Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * nbtpreprocesskeys.c
4 : * Preprocessing for Postgres btree scan keys.
5 : *
6 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/access/nbtree/nbtpreprocesskeys.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 :
16 : #include "postgres.h"
17 :
18 : #include "access/nbtree.h"
19 : #include "access/relscan.h"
20 : #include "common/int.h"
21 : #include "lib/qunique.h"
22 : #include "utils/array.h"
23 : #include "utils/lsyscache.h"
24 : #include "utils/memutils.h"
25 : #include "utils/rel.h"
26 :
27 : typedef struct BTScanKeyPreproc
28 : {
29 : ScanKey inkey;
30 : int inkeyi;
31 : int arrayidx;
32 : } BTScanKeyPreproc;
33 :
34 : typedef struct BTSortArrayContext
35 : {
36 : FmgrInfo *sortproc;
37 : Oid collation;
38 : bool reverse;
39 : } BTSortArrayContext;
40 :
41 : static bool _bt_fix_scankey_strategy(ScanKey skey, int16 *indoption);
42 : static void _bt_mark_scankey_required(ScanKey skey);
43 : static bool _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
44 : ScanKey leftarg, ScanKey rightarg,
45 : BTArrayKeyInfo *array, FmgrInfo *orderproc,
46 : bool *result);
47 : static bool _bt_compare_array_scankey_args(IndexScanDesc scan,
48 : ScanKey arraysk, ScanKey skey,
49 : FmgrInfo *orderproc, BTArrayKeyInfo *array,
50 : bool *qual_ok);
51 : static bool _bt_saoparray_shrink(IndexScanDesc scan, ScanKey arraysk,
52 : ScanKey skey, FmgrInfo *orderproc,
53 : BTArrayKeyInfo *array, bool *qual_ok);
54 : static bool _bt_skiparray_shrink(IndexScanDesc scan, ScanKey skey,
55 : BTArrayKeyInfo *array, bool *qual_ok);
56 : static void _bt_skiparray_strat_adjust(IndexScanDesc scan, ScanKey arraysk,
57 : BTArrayKeyInfo *array);
58 : static void _bt_skiparray_strat_decrement(IndexScanDesc scan, ScanKey arraysk,
59 : BTArrayKeyInfo *array);
60 : static void _bt_skiparray_strat_increment(IndexScanDesc scan, ScanKey arraysk,
61 : BTArrayKeyInfo *array);
62 : static void _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap);
63 : static int _bt_reorder_array_cmp(const void *a, const void *b);
64 : static ScanKey _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys);
65 : static void _bt_preprocess_array_keys_final(IndexScanDesc scan, int *keyDataMap);
66 : static int _bt_num_array_keys(IndexScanDesc scan, Oid *skip_eq_ops_out,
67 : int *numSkipArrayKeys_out);
68 : static Datum _bt_find_extreme_element(IndexScanDesc scan, ScanKey skey,
69 : Oid elemtype, StrategyNumber strat,
70 : Datum *elems, int nelems);
71 : static void _bt_setup_array_cmp(IndexScanDesc scan, ScanKey skey, Oid elemtype,
72 : FmgrInfo *orderproc, FmgrInfo **sortprocp);
73 : static int _bt_sort_array_elements(ScanKey skey, FmgrInfo *sortproc,
74 : bool reverse, Datum *elems, int nelems);
75 : static bool _bt_merge_arrays(IndexScanDesc scan, ScanKey skey,
76 : FmgrInfo *sortproc, bool reverse,
77 : Oid origelemtype, Oid nextelemtype,
78 : Datum *elems_orig, int *nelems_orig,
79 : Datum *elems_next, int nelems_next);
80 : static int _bt_compare_array_elements(const void *a, const void *b, void *arg);
81 :
82 :
83 : /*
84 : * _bt_preprocess_keys() -- Preprocess scan keys
85 : *
86 : * The given search-type keys (taken from scan->keyData[])
87 : * are copied to so->keyData[] with possible transformation.
88 : * scan->numberOfKeys is the number of input keys, so->numberOfKeys gets
89 : * the number of output keys. Calling here a second or subsequent time
90 : * (during the same btrescan) is a no-op.
91 : *
92 : * The output keys are marked with additional sk_flags bits beyond the
93 : * system-standard bits supplied by the caller. The DESC and NULLS_FIRST
94 : * indoption bits for the relevant index attribute are copied into the flags.
95 : * Also, for a DESC column, we commute (flip) all the sk_strategy numbers
96 : * so that the index sorts in the desired direction.
97 : *
98 : * One key purpose of this routine is to discover which scan keys must be
99 : * satisfied to continue the scan. It also attempts to eliminate redundant
100 : * keys and detect contradictory keys. (If the index opfamily provides
101 : * incomplete sets of cross-type operators, we may fail to detect redundant
102 : * or contradictory keys, but we can survive that.)
103 : *
104 : * Required output keys are sorted by index attribute. Presently we expect
105 : * (but verify) that the input keys are already so sorted --- this is done
106 : * by match_clauses_to_index() in indxpath.c. Some reordering of the keys
107 : * within each attribute may be done as a byproduct of the processing here.
108 : * That process must leave array scan keys (within an attribute) in the same
109 : * order as corresponding entries from the scan's BTArrayKeyInfo array info.
110 : * We might also construct skip array scan keys that weren't present in the
111 : * original input keys; these are also output in standard attribute order.
112 : *
113 : * The output keys are marked with flags SK_BT_REQFWD and/or SK_BT_REQBKWD
114 : * if they must be satisfied in order to continue the scan forward or backward
115 : * respectively. _bt_checkkeys uses these flags. For example, if the quals
116 : * are "x = 1 AND y < 4 AND z < 5", then _bt_checkkeys will reject a tuple
117 : * (1,2,7), but we must continue the scan in case there are tuples (1,3,z).
118 : * But once we reach tuples like (1,4,z) we can stop scanning because no
119 : * later tuples could match. This is reflected by marking the x and y keys,
120 : * but not the z key, with SK_BT_REQFWD. In general, the keys for leading
121 : * attributes with "=" keys are marked both SK_BT_REQFWD and SK_BT_REQBKWD.
122 : * For the first attribute without an "=" key, any "<" and "<=" keys are
123 : * marked SK_BT_REQFWD while any ">" and ">=" keys are marked SK_BT_REQBKWD.
124 : * This can be seen to be correct by considering the above example.
125 : *
126 : * If we never generated skip array scan keys, it would be possible for "gaps"
127 : * to appear that make it unsafe to mark any subsequent input scan keys
128 : * (copied from scan->keyData[]) as required to continue the scan. Prior to
129 : * Postgres 18, a qual like "WHERE y = 4" always resulted in a full scan.
130 : * This qual now becomes "WHERE x = ANY('{every possible x value}') and y = 4"
131 : * on output. In other words, preprocessing now adds a skip array on "x".
132 : * This has the potential to be much more efficient than a full index scan
133 : * (though it behaves like a full scan when there's many distinct "x" values).
134 : *
135 : * Typically, redundant keys are eliminated: we keep only the tightest
136 : * >/>= bound and the tightest </<= bound, and if there's an = key then
137 : * that's the only one returned. (So, we return either a single = key,
138 : * or one or two boundary-condition keys for each attr.) However, if we
139 : * cannot compare two keys for lack of a suitable cross-type operator,
140 : * we cannot eliminate either key.
141 : *
142 : * When all redundant keys could not be eliminated, we'll output a key array
143 : * that can more or less be treated as if it had no redundant keys. Suppose
144 : * we have "x > 4::int AND x > 10::bigint AND x < 70", and we are unable to
145 : * determine which > key is more restrictive for lack of a suitable cross-type
146 : * operator. We'll arbitrarily pick one of the > keys; the other > key won't
147 : * be marked required. Obviously, the scan will be less efficient if we
148 : * choose x > 4 over x > 10 -- but it can still largely proceed as if there
149 : * was only a single > condition. "x > 10" will be placed at the end of the
150 : * so->keyData[] output array. It'll always be evaluated last, after the keys
151 : * that could be marked required in the usual way (after "x > 4 AND x < 70").
152 : * This can sometimes result in so->keyData[] keys that aren't even in index
153 : * attribute order (if the qual involves multiple attributes). The scan's
154 : * required keys will still be in attribute order, though, so it can't matter.
155 : *
156 : * This scheme ensures that _bt_first always uses the same set of keys at the
157 : * start of a forwards scan as those _bt_checkkeys uses to determine when to
158 : * end a similar backwards scan (and vice-versa). _bt_advance_array_keys
159 : * depends on this: it expects to be able to reliably predict what the next
160 : * _bt_first call will do by testing whether _bt_checkkeys' routines report
161 : * that the final tuple on the page is past the end of matches for the scan's
162 : * keys with the scan direction flipped. If it is (if continuescan=false),
163 : * then it follows that calling _bt_first will, at a minimum, relocate the
164 : * scan to the very next leaf page (in the current scan direction).
165 : *
166 : * As a byproduct of this work, we can detect contradictory quals such
167 : * as "x = 1 AND x > 2". If we see that, we return so->qual_ok = false,
168 : * indicating the scan need not be run at all since no tuples can match.
169 : * (In this case we do not bother completing the output key array!)
170 : * Again, missing cross-type operators might cause us to fail to prove the
171 : * quals contradictory when they really are, but the scan will work correctly.
172 : *
173 : * Skip array = keys will even be generated in the presence of "contradictory"
174 : * inequality quals when it'll enable marking later input quals as required.
175 : * We'll merge any such inequalities into the generated skip array by setting
176 : * its array.low_compare or array.high_compare key field. The resulting skip
177 : * array will generate its array elements from a range that's constrained by
178 : * any merged input inequalities (which won't get output in so->keyData[]).
179 : *
180 : * Row comparison keys currently have a couple of notable limitations.
181 : * Right now we just transfer them into the preprocessed array without any
182 : * editorialization. We can treat them the same as an ordinary inequality
183 : * comparison on the row's first index column, for the purposes of the logic
184 : * about required keys. Also, we are unable to merge a row comparison key
185 : * into a skip array (only ordinary inequalities are merged). A key that
186 : * comes after a Row comparison key is therefore never marked as required.
187 : *
188 : * Note: the reason we have to copy the preprocessed scan keys into private
189 : * storage is that we are modifying the array based on comparisons of the
190 : * key argument values, which could change on a rescan. Therefore we can't
191 : * overwrite the source data.
192 : */
193 : void
194 16427264 : _bt_preprocess_keys(IndexScanDesc scan)
195 : {
196 16427264 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
197 16427264 : int numberOfKeys = scan->numberOfKeys;
198 16427264 : int16 *indoption = scan->indexRelation->rd_indoption;
199 : int new_numberOfKeys;
200 : int numberOfEqualCols;
201 : ScanKey inkeys;
202 : BTScanKeyPreproc xform[BTMaxStrategyNumber];
203 : bool test_result,
204 16427264 : redundant_key_kept = false;
205 : AttrNumber attno;
206 : ScanKey arrayKeyData;
207 16427264 : int *keyDataMap = NULL;
208 16427264 : int arrayidx = 0;
209 :
210 16427264 : if (so->numberOfKeys > 0)
211 : {
212 : /*
213 : * Only need to do preprocessing once per btrescan, at most. All
214 : * calls after the first are handled as no-ops.
215 : */
216 8553504 : return;
217 : }
218 :
219 : /* initialize result variables */
220 16409730 : so->qual_ok = true;
221 16409730 : so->numberOfKeys = 0;
222 :
223 16409730 : if (numberOfKeys < 1)
224 13218 : return; /* done if qual-less scan */
225 :
226 : /* If any keys are SK_SEARCHARRAY type, set up array-key info */
227 16396512 : arrayKeyData = _bt_preprocess_array_keys(scan, &numberOfKeys);
228 16396512 : if (!so->qual_ok)
229 : {
230 : /* unmatchable array, so give up */
231 18 : return;
232 : }
233 :
234 : /*
235 : * Treat arrayKeyData[] (a partially preprocessed copy of scan->keyData[])
236 : * as our input if _bt_preprocess_array_keys just allocated it, else just
237 : * use scan->keyData[]
238 : */
239 16396494 : if (arrayKeyData)
240 : {
241 71350 : inkeys = arrayKeyData;
242 :
243 : /* Also maintain keyDataMap for remapping so->orderProcs[] later */
244 71350 : keyDataMap = MemoryContextAlloc(so->arrayContext,
245 : numberOfKeys * sizeof(int));
246 :
247 : /*
248 : * Also enlarge output array when it might otherwise not have room for
249 : * a skip array's scan key
250 : */
251 71350 : if (numberOfKeys > scan->numberOfKeys)
252 3814 : so->keyData = repalloc(so->keyData,
253 : numberOfKeys * sizeof(ScanKeyData));
254 : }
255 : else
256 16325144 : inkeys = scan->keyData;
257 :
258 : /* we check that input keys are correctly ordered */
259 16396494 : if (inkeys[0].sk_attno < 1)
260 0 : elog(ERROR, "btree index keys must be ordered by attribute");
261 :
262 : /* We can short-circuit most of the work if there's just one key */
263 16396494 : if (numberOfKeys == 1)
264 : {
265 : /* Apply indoption to scankey (might change sk_strategy!) */
266 8521758 : if (!_bt_fix_scankey_strategy(&inkeys[0], indoption))
267 1110 : so->qual_ok = false;
268 8521758 : memcpy(&so->keyData[0], &inkeys[0], sizeof(ScanKeyData));
269 8521758 : so->numberOfKeys = 1;
270 : /* We can mark the qual as required if it's for first index col */
271 8521758 : if (inkeys[0].sk_attno == 1)
272 8521758 : _bt_mark_scankey_required(&so->keyData[0]);
273 : if (arrayKeyData)
274 : {
275 : /*
276 : * Don't call _bt_preprocess_array_keys_final in this fast path
277 : * (we'll miss out on the single value array transformation, but
278 : * that's not nearly as important when there's only one scan key)
279 : */
280 : Assert(so->keyData[0].sk_flags & SK_SEARCHARRAY);
281 : Assert(so->keyData[0].sk_strategy != BTEqualStrategyNumber ||
282 : (so->arrayKeys[0].scan_key == 0 &&
283 : !(so->keyData[0].sk_flags & SK_BT_SKIP) &&
284 : OidIsValid(so->orderProcs[0].fn_oid)));
285 : }
286 :
287 8521758 : return;
288 : }
289 :
290 : /*
291 : * Otherwise, do the full set of pushups.
292 : */
293 7874736 : new_numberOfKeys = 0;
294 7874736 : numberOfEqualCols = 0;
295 :
296 : /*
297 : * Initialize for processing of keys for attr 1.
298 : *
299 : * xform[i] points to the currently best scan key of strategy type i+1; it
300 : * is NULL if we haven't yet found such a key for this attr.
301 : */
302 7874736 : attno = 1;
303 7874736 : memset(xform, 0, sizeof(xform));
304 :
305 : /*
306 : * Loop iterates from 0 to numberOfKeys inclusive; we use the last pass to
307 : * handle after-last-key processing. Actual exit from the loop is at the
308 : * "break" statement below.
309 : */
310 7874736 : for (int i = 0;; i++)
311 17286380 : {
312 25161116 : ScanKey inkey = inkeys + i;
313 : int j;
314 :
315 25161116 : if (i < numberOfKeys)
316 : {
317 : /* Apply indoption to scankey (might change sk_strategy!) */
318 17287320 : if (!_bt_fix_scankey_strategy(inkey, indoption))
319 : {
320 : /* NULL can't be matched, so give up */
321 934 : so->qual_ok = false;
322 934 : return;
323 : }
324 : }
325 :
326 : /*
327 : * If we are at the end of the keys for a particular attr, finish up
328 : * processing and emit the cleaned-up keys.
329 : */
330 25160182 : if (i == numberOfKeys || inkey->sk_attno != attno)
331 : {
332 17283894 : int priorNumberOfEqualCols = numberOfEqualCols;
333 :
334 : /* check input keys are correctly ordered */
335 17283894 : if (i < numberOfKeys && inkey->sk_attno < attno)
336 0 : elog(ERROR, "btree index keys must be ordered by attribute");
337 :
338 : /*
339 : * If = has been specified, all other keys can be eliminated as
340 : * redundant. Note that this is no less true if the = key is
341 : * SEARCHARRAY; the only real difference is that the inequality
342 : * key _becomes_ redundant by making _bt_compare_scankey_args
343 : * eliminate the subset of elements that won't need to be matched
344 : * (with SAOP arrays and skip arrays alike).
345 : *
346 : * If we have a case like "key = 1 AND key > 2", we set qual_ok to
347 : * false and abandon further processing. We'll do the same thing
348 : * given a case like "key IN (0, 1) AND key > 2".
349 : *
350 : * We also have to deal with the case of "key IS NULL", which is
351 : * unsatisfiable in combination with any other index condition. By
352 : * the time we get here, that's been classified as an equality
353 : * check, and we've rejected any combination of it with a regular
354 : * equality condition; but not with other types of conditions.
355 : */
356 17283894 : if (xform[BTEqualStrategyNumber - 1].inkey)
357 : {
358 15586308 : ScanKey eq = xform[BTEqualStrategyNumber - 1].inkey;
359 15586308 : BTArrayKeyInfo *array = NULL;
360 15586308 : FmgrInfo *orderproc = NULL;
361 :
362 15586308 : if (arrayKeyData && (eq->sk_flags & SK_SEARCHARRAY))
363 : {
364 : int eq_in_ikey,
365 : eq_arrayidx;
366 :
367 4660 : eq_in_ikey = xform[BTEqualStrategyNumber - 1].inkeyi;
368 4660 : eq_arrayidx = xform[BTEqualStrategyNumber - 1].arrayidx;
369 4660 : array = &so->arrayKeys[eq_arrayidx - 1];
370 4660 : orderproc = so->orderProcs + eq_in_ikey;
371 :
372 : Assert(array->scan_key == eq_in_ikey);
373 : Assert(OidIsValid(orderproc->fn_oid));
374 : }
375 :
376 93517692 : for (j = BTMaxStrategyNumber; --j >= 0;)
377 : {
378 77931420 : ScanKey chk = xform[j].inkey;
379 :
380 77931420 : if (!chk || j == (BTEqualStrategyNumber - 1))
381 77930862 : continue;
382 :
383 558 : if (eq->sk_flags & SK_SEARCHNULL)
384 : {
385 : /* IS NULL is contradictory to anything else */
386 24 : so->qual_ok = false;
387 24 : return;
388 : }
389 :
390 534 : if (_bt_compare_scankey_args(scan, chk, eq, chk,
391 : array, orderproc,
392 : &test_result))
393 : {
394 528 : if (!test_result)
395 : {
396 : /* keys proven mutually contradictory */
397 12 : so->qual_ok = false;
398 12 : return;
399 : }
400 : /* else discard the redundant non-equality key */
401 516 : xform[j].inkey = NULL;
402 516 : xform[j].inkeyi = -1;
403 : }
404 : else
405 6 : redundant_key_kept = true;
406 : }
407 : /* track number of attrs for which we have "=" keys */
408 15586272 : numberOfEqualCols++;
409 : }
410 :
411 : /* try to keep only one of <, <= */
412 17283858 : if (xform[BTLessStrategyNumber - 1].inkey &&
413 1916 : xform[BTLessEqualStrategyNumber - 1].inkey)
414 : {
415 6 : ScanKey lt = xform[BTLessStrategyNumber - 1].inkey;
416 6 : ScanKey le = xform[BTLessEqualStrategyNumber - 1].inkey;
417 :
418 6 : if (_bt_compare_scankey_args(scan, le, lt, le, NULL, NULL,
419 : &test_result))
420 : {
421 6 : if (test_result)
422 6 : xform[BTLessEqualStrategyNumber - 1].inkey = NULL;
423 : else
424 0 : xform[BTLessStrategyNumber - 1].inkey = NULL;
425 : }
426 : else
427 0 : redundant_key_kept = true;
428 : }
429 :
430 : /* try to keep only one of >, >= */
431 17283858 : if (xform[BTGreaterStrategyNumber - 1].inkey &&
432 1693256 : xform[BTGreaterEqualStrategyNumber - 1].inkey)
433 : {
434 6 : ScanKey gt = xform[BTGreaterStrategyNumber - 1].inkey;
435 6 : ScanKey ge = xform[BTGreaterEqualStrategyNumber - 1].inkey;
436 :
437 6 : if (_bt_compare_scankey_args(scan, ge, gt, ge, NULL, NULL,
438 : &test_result))
439 : {
440 6 : if (test_result)
441 0 : xform[BTGreaterEqualStrategyNumber - 1].inkey = NULL;
442 : else
443 6 : xform[BTGreaterStrategyNumber - 1].inkey = NULL;
444 : }
445 : else
446 0 : redundant_key_kept = true;
447 : }
448 :
449 : /*
450 : * Emit the cleaned-up keys into the so->keyData[] array, and then
451 : * mark them if they are required. They are required (possibly
452 : * only in one direction) if all attrs before this one had "=".
453 : *
454 : * In practice we'll rarely output non-required scan keys here;
455 : * typically, _bt_preprocess_array_keys has already added "=" keys
456 : * sufficient to form an unbroken series of "=" constraints on all
457 : * attrs prior to the attr from the final scan->keyData[] key.
458 : */
459 103703148 : for (j = BTMaxStrategyNumber; --j >= 0;)
460 : {
461 86419290 : if (xform[j].inkey)
462 : {
463 17285702 : ScanKey outkey = &so->keyData[new_numberOfKeys++];
464 :
465 17285702 : memcpy(outkey, xform[j].inkey, sizeof(ScanKeyData));
466 17285702 : if (arrayKeyData)
467 9548 : keyDataMap[new_numberOfKeys - 1] = xform[j].inkeyi;
468 17285702 : if (priorNumberOfEqualCols == attno - 1)
469 17285702 : _bt_mark_scankey_required(outkey);
470 : }
471 : }
472 :
473 : /*
474 : * Exit loop here if done.
475 : */
476 17283858 : if (i == numberOfKeys)
477 7873760 : break;
478 :
479 : /* Re-initialize for new attno */
480 9410098 : attno = inkey->sk_attno;
481 9410098 : memset(xform, 0, sizeof(xform));
482 : }
483 :
484 : /* check strategy this key's operator corresponds to */
485 17286386 : j = inkey->sk_strategy - 1;
486 :
487 17286386 : if (inkey->sk_strategy == BTEqualStrategyNumber &&
488 15586350 : (inkey->sk_flags & SK_SEARCHARRAY))
489 : {
490 : /* must track how input scan keys map to arrays */
491 : Assert(arrayKeyData);
492 4666 : arrayidx++;
493 : }
494 :
495 : /*
496 : * have we seen a scan key for this same attribute and using this same
497 : * operator strategy before now?
498 : */
499 17286386 : if (xform[j].inkey == NULL)
500 : {
501 : /* nope, so this scan key wins by default (at least for now) */
502 17286320 : xform[j].inkey = inkey;
503 17286320 : xform[j].inkeyi = i;
504 17286320 : xform[j].arrayidx = arrayidx;
505 : }
506 : else
507 : {
508 66 : FmgrInfo *orderproc = NULL;
509 66 : BTArrayKeyInfo *array = NULL;
510 :
511 : /*
512 : * Seen one of these before, so keep only the more restrictive key
513 : * if possible
514 : */
515 66 : if (j == (BTEqualStrategyNumber - 1) && arrayKeyData)
516 : {
517 : /*
518 : * Have to set up array keys
519 : */
520 18 : if (inkey->sk_flags & SK_SEARCHARRAY)
521 : {
522 0 : array = &so->arrayKeys[arrayidx - 1];
523 0 : orderproc = so->orderProcs + i;
524 :
525 : Assert(array->scan_key == i);
526 : Assert(OidIsValid(orderproc->fn_oid));
527 : Assert(!(inkey->sk_flags & SK_BT_SKIP));
528 : }
529 18 : else if (xform[j].inkey->sk_flags & SK_SEARCHARRAY)
530 : {
531 12 : array = &so->arrayKeys[xform[j].arrayidx - 1];
532 12 : orderproc = so->orderProcs + xform[j].inkeyi;
533 :
534 : Assert(array->scan_key == xform[j].inkeyi);
535 : Assert(OidIsValid(orderproc->fn_oid));
536 : Assert(!(xform[j].inkey->sk_flags & SK_BT_SKIP));
537 : }
538 :
539 : /*
540 : * Both scan keys might have arrays, in which case we'll
541 : * arbitrarily pass only one of the arrays. That won't
542 : * matter, since _bt_compare_scankey_args is aware that two
543 : * SEARCHARRAY scan keys mean that _bt_preprocess_array_keys
544 : * failed to eliminate redundant arrays through array merging.
545 : * _bt_compare_scankey_args just returns false when it sees
546 : * this; it won't even try to examine either array.
547 : */
548 : }
549 :
550 66 : if (_bt_compare_scankey_args(scan, inkey, inkey, xform[j].inkey,
551 : array, orderproc, &test_result))
552 : {
553 : /* Have all we need to determine redundancy */
554 66 : if (test_result)
555 : {
556 : /*
557 : * New key is more restrictive, and so replaces old key...
558 : */
559 54 : if (j != (BTEqualStrategyNumber - 1) ||
560 18 : !(xform[j].inkey->sk_flags & SK_SEARCHARRAY))
561 : {
562 48 : xform[j].inkey = inkey;
563 48 : xform[j].inkeyi = i;
564 48 : xform[j].arrayidx = arrayidx;
565 : }
566 : else
567 : {
568 : /*
569 : * ...unless we have to keep the old key because it's
570 : * an array that rendered the new key redundant. We
571 : * need to make sure that we don't throw away an array
572 : * scan key. _bt_preprocess_array_keys_final expects
573 : * us to keep all of the arrays that weren't already
574 : * eliminated by _bt_preprocess_array_keys earlier on.
575 : */
576 : Assert(!(inkey->sk_flags & SK_SEARCHARRAY));
577 : }
578 : }
579 12 : else if (j == (BTEqualStrategyNumber - 1))
580 : {
581 : /* key == a && key == b, but a != b */
582 6 : so->qual_ok = false;
583 6 : return;
584 : }
585 : /* else old key is more restrictive, keep it */
586 : }
587 : else
588 : {
589 : /*
590 : * We can't determine which key is more restrictive. Push
591 : * xform[j] directly to the output array, then set xform[j] to
592 : * the new scan key.
593 : *
594 : * Note: We do things this way around so that our arrays are
595 : * always in the same order as their corresponding scan keys.
596 : * _bt_preprocess_array_keys_final expects this.
597 : */
598 0 : ScanKey outkey = &so->keyData[new_numberOfKeys++];
599 :
600 0 : memcpy(outkey, xform[j].inkey, sizeof(ScanKeyData));
601 0 : if (arrayKeyData)
602 0 : keyDataMap[new_numberOfKeys - 1] = xform[j].inkeyi;
603 0 : if (numberOfEqualCols == attno - 1)
604 0 : _bt_mark_scankey_required(outkey);
605 0 : xform[j].inkey = inkey;
606 0 : xform[j].inkeyi = i;
607 0 : xform[j].arrayidx = arrayidx;
608 0 : redundant_key_kept = true;
609 : }
610 : }
611 : }
612 :
613 7873760 : so->numberOfKeys = new_numberOfKeys;
614 :
615 : /*
616 : * Now that we've built a temporary mapping from so->keyData[] (output
617 : * scan keys) to arrayKeyData[] (our input scan keys), fix array->scan_key
618 : * references. Also consolidate the so->orderProcs[] array such that it
619 : * can be subscripted using so->keyData[]-wise offsets.
620 : */
621 7873760 : if (arrayKeyData)
622 4312 : _bt_preprocess_array_keys_final(scan, keyDataMap);
623 :
624 : /*
625 : * If there are remaining redundant inequality keys, we must make sure
626 : * that each index attribute has no more than one required >/>= key, and
627 : * no more than one required </<= key. Attributes that have one or more
628 : * required = keys now must keep only one required key (the first = key).
629 : */
630 7873760 : if (unlikely(redundant_key_kept) && so->qual_ok)
631 6 : _bt_unmark_keys(scan, keyDataMap);
632 :
633 : /* Could pfree arrayKeyData/keyDataMap now, but not worth the cycles */
634 : }
635 :
636 : /*
637 : * Adjust a scankey's strategy and flags setting as needed for indoptions.
638 : *
639 : * We copy the appropriate indoption value into the scankey sk_flags
640 : * (shifting to avoid clobbering system-defined flag bits). Also, if
641 : * the DESC option is set, commute (flip) the operator strategy number.
642 : *
643 : * A secondary purpose is to check for IS NULL/NOT NULL scankeys and set up
644 : * the strategy field correctly for them.
645 : *
646 : * Lastly, for ordinary scankeys (not IS NULL/NOT NULL), we check for a
647 : * NULL comparison value. Since all btree operators are assumed strict,
648 : * a NULL means that the qual cannot be satisfied. We return true if the
649 : * comparison value isn't NULL, or false if the scan should be abandoned.
650 : *
651 : * This function is applied to the *input* scankey structure; therefore
652 : * on a rescan we will be looking at already-processed scankeys. Hence
653 : * we have to be careful not to re-commute the strategy if we already did it.
654 : * It's a bit ugly to modify the caller's copy of the scankey but in practice
655 : * there shouldn't be any problem, since the index's indoptions are certainly
656 : * not going to change while the scankey survives.
657 : */
658 : static bool
659 25809078 : _bt_fix_scankey_strategy(ScanKey skey, int16 *indoption)
660 : {
661 : int addflags;
662 :
663 25809078 : addflags = indoption[skey->sk_attno - 1] << SK_BT_INDOPTION_SHIFT;
664 :
665 : /*
666 : * We treat all btree operators as strict (even if they're not so marked
667 : * in pg_proc). This means that it is impossible for an operator condition
668 : * with a NULL comparison constant to succeed, and we can reject it right
669 : * away.
670 : *
671 : * However, we now also support "x IS NULL" clauses as search conditions,
672 : * so in that case keep going. The planner has not filled in any
673 : * particular strategy in this case, so set it to BTEqualStrategyNumber
674 : * --- we can treat IS NULL as an equality operator for purposes of search
675 : * strategy.
676 : *
677 : * Likewise, "x IS NOT NULL" is supported. We treat that as either "less
678 : * than NULL" in a NULLS LAST index, or "greater than NULL" in a NULLS
679 : * FIRST index.
680 : *
681 : * Note: someday we might have to fill in sk_collation from the index
682 : * column's collation. At the moment this is a non-issue because we'll
683 : * never actually call the comparison operator on a NULL.
684 : */
685 25809078 : if (skey->sk_flags & SK_ISNULL)
686 : {
687 : /* SK_ISNULL shouldn't be set in a row header scankey */
688 : Assert(!(skey->sk_flags & SK_ROW_HEADER));
689 :
690 : /* Set indoption flags in scankey (might be done already) */
691 128026 : skey->sk_flags |= addflags;
692 :
693 : /* Set correct strategy for IS NULL or NOT NULL search */
694 128026 : if (skey->sk_flags & SK_SEARCHNULL)
695 : {
696 152 : skey->sk_strategy = BTEqualStrategyNumber;
697 152 : skey->sk_subtype = InvalidOid;
698 152 : skey->sk_collation = InvalidOid;
699 : }
700 127874 : else if (skey->sk_flags & SK_SEARCHNOTNULL)
701 : {
702 125836 : if (skey->sk_flags & SK_BT_NULLS_FIRST)
703 36 : skey->sk_strategy = BTGreaterStrategyNumber;
704 : else
705 125800 : skey->sk_strategy = BTLessStrategyNumber;
706 125836 : skey->sk_subtype = InvalidOid;
707 125836 : skey->sk_collation = InvalidOid;
708 : }
709 : else
710 : {
711 : /* regular qual, so it cannot be satisfied */
712 2038 : return false;
713 : }
714 :
715 : /* Needn't do the rest */
716 125988 : return true;
717 : }
718 :
719 : /* Adjust strategy for DESC, if we didn't already */
720 25681052 : if ((addflags & SK_BT_DESC) && !(skey->sk_flags & SK_BT_DESC))
721 78 : skey->sk_strategy = BTCommuteStrategyNumber(skey->sk_strategy);
722 25681052 : skey->sk_flags |= addflags;
723 :
724 : /* If it's a row header, fix row member flags and strategies similarly */
725 25681052 : if (skey->sk_flags & SK_ROW_HEADER)
726 : {
727 84 : ScanKey subkey = (ScanKey) DatumGetPointer(skey->sk_argument);
728 :
729 84 : if (subkey->sk_flags & SK_ISNULL)
730 : {
731 : /* First row member is NULL, so RowCompare is unsatisfiable */
732 : Assert(subkey->sk_flags & SK_ROW_MEMBER);
733 6 : return false;
734 : }
735 :
736 : for (;;)
737 : {
738 78 : Assert(subkey->sk_flags & SK_ROW_MEMBER);
739 156 : addflags = indoption[subkey->sk_attno - 1] << SK_BT_INDOPTION_SHIFT;
740 156 : if ((addflags & SK_BT_DESC) && !(subkey->sk_flags & SK_BT_DESC))
741 0 : subkey->sk_strategy = BTCommuteStrategyNumber(subkey->sk_strategy);
742 156 : subkey->sk_flags |= addflags;
743 156 : if (subkey->sk_flags & SK_ROW_END)
744 78 : break;
745 78 : subkey++;
746 : }
747 : }
748 :
749 25681046 : return true;
750 : }
751 :
752 : /*
753 : * Mark a scankey as "required to continue the scan".
754 : *
755 : * Depending on the operator type, the key may be required for both scan
756 : * directions or just one. Also, if the key is a row comparison header,
757 : * we have to mark the appropriate subsidiary ScanKeys as required. In such
758 : * cases, the first subsidiary key is required, but subsequent ones are
759 : * required only as long as they correspond to successive index columns and
760 : * match the leading column as to sort direction. Otherwise the row
761 : * comparison ordering is different from the index ordering and so we can't
762 : * stop the scan on the basis of those lower-order columns.
763 : *
764 : * Note: when we set required-key flag bits in a subsidiary scankey, we are
765 : * scribbling on a data structure belonging to the index AM's caller, not on
766 : * our private copy. This should be OK because the marking will not change
767 : * from scan to scan within a query, and so we'd just re-mark the same way
768 : * anyway on a rescan. Something to keep an eye on though.
769 : */
770 : static void
771 25807460 : _bt_mark_scankey_required(ScanKey skey)
772 : {
773 : int addflags;
774 :
775 25807460 : switch (skey->sk_strategy)
776 : {
777 128710 : case BTLessStrategyNumber:
778 : case BTLessEqualStrategyNumber:
779 128710 : addflags = SK_BT_REQFWD;
780 128710 : break;
781 23979992 : case BTEqualStrategyNumber:
782 23979992 : addflags = SK_BT_REQFWD | SK_BT_REQBKWD;
783 23979992 : break;
784 1698758 : case BTGreaterEqualStrategyNumber:
785 : case BTGreaterStrategyNumber:
786 1698758 : addflags = SK_BT_REQBKWD;
787 1698758 : break;
788 0 : default:
789 0 : elog(ERROR, "unrecognized StrategyNumber: %d",
790 : (int) skey->sk_strategy);
791 : addflags = 0; /* keep compiler quiet */
792 : break;
793 : }
794 :
795 25807460 : skey->sk_flags |= addflags;
796 :
797 25807460 : if (skey->sk_flags & SK_ROW_HEADER)
798 : {
799 84 : ScanKey subkey = (ScanKey) DatumGetPointer(skey->sk_argument);
800 84 : AttrNumber attno = skey->sk_attno;
801 :
802 : /* First subkey should be same column/operator as the header */
803 : Assert(subkey->sk_attno == attno);
804 : Assert(subkey->sk_strategy == skey->sk_strategy);
805 :
806 : for (;;)
807 : {
808 84 : Assert(subkey->sk_flags & SK_ROW_MEMBER);
809 168 : if (subkey->sk_attno != attno)
810 12 : break; /* non-adjacent key, so not required */
811 156 : if (subkey->sk_strategy != skey->sk_strategy)
812 0 : break; /* wrong direction, so not required */
813 156 : subkey->sk_flags |= addflags;
814 156 : if (subkey->sk_flags & SK_ROW_END)
815 72 : break;
816 84 : subkey++;
817 84 : attno++;
818 : }
819 : }
820 25807460 : }
821 :
822 : /*
823 : * Compare two scankey values using a specified operator.
824 : *
825 : * The test we want to perform is logically "leftarg op rightarg", where
826 : * leftarg and rightarg are the sk_argument values in those ScanKeys, and
827 : * the comparison operator is the one in the op ScanKey. However, in
828 : * cross-data-type situations we may need to look up the correct operator in
829 : * the index's opfamily: it is the one having amopstrategy = op->sk_strategy
830 : * and amoplefttype/amoprighttype equal to the two argument datatypes.
831 : *
832 : * If the opfamily doesn't supply a complete set of cross-type operators we
833 : * may not be able to make the comparison. If we can make the comparison
834 : * we store the operator result in *result and return true. We return false
835 : * if the comparison could not be made.
836 : *
837 : * If either leftarg or rightarg are an array, we'll apply array-specific
838 : * rules to determine which array elements are redundant on behalf of caller.
839 : * It is up to our caller to save whichever of the two scan keys is the array,
840 : * and discard the non-array scan key (the non-array scan key is guaranteed to
841 : * be redundant with any complete opfamily). Caller isn't expected to call
842 : * here with a pair of array scan keys provided we're dealing with a complete
843 : * opfamily (_bt_preprocess_array_keys will merge array keys together to make
844 : * sure of that).
845 : *
846 : * Note: we'll also shrink caller's array as needed to eliminate redundant
847 : * array elements. One reason why caller should prefer to discard non-array
848 : * scan keys is so that we'll have the opportunity to shrink the array
849 : * multiple times, in multiple calls (for each of several other scan keys on
850 : * the same index attribute).
851 : *
852 : * Note: op always points at the same ScanKey as either leftarg or rightarg.
853 : * Since we don't scribble on the scankeys themselves, this aliasing should
854 : * cause no trouble.
855 : *
856 : * Note: this routine needs to be insensitive to any DESC option applied
857 : * to the index column. For example, "x < 4" is a tighter constraint than
858 : * "x < 5" regardless of which way the index is sorted.
859 : */
860 : static bool
861 624 : _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
862 : ScanKey leftarg, ScanKey rightarg,
863 : BTArrayKeyInfo *array, FmgrInfo *orderproc,
864 : bool *result)
865 : {
866 624 : Relation rel = scan->indexRelation;
867 : Oid lefttype,
868 : righttype,
869 : optype,
870 : opcintype,
871 : cmp_op;
872 : StrategyNumber strat;
873 :
874 : Assert(!((leftarg->sk_flags | rightarg->sk_flags) & SK_ROW_MEMBER));
875 :
876 : /*
877 : * First, deal with cases where one or both args are NULL. This should
878 : * only happen when the scankeys represent IS NULL/NOT NULL conditions.
879 : */
880 624 : if ((leftarg->sk_flags | rightarg->sk_flags) & SK_ISNULL)
881 : {
882 : bool leftnull,
883 : rightnull;
884 :
885 : /* Handle skip array comparison with IS NOT NULL scan key */
886 174 : if ((leftarg->sk_flags | rightarg->sk_flags) & SK_BT_SKIP)
887 : {
888 : /* Shouldn't generate skip array in presence of IS NULL key */
889 : Assert(!((leftarg->sk_flags | rightarg->sk_flags) & SK_SEARCHNULL));
890 : Assert((leftarg->sk_flags | rightarg->sk_flags) & SK_SEARCHNOTNULL);
891 :
892 : /* Skip array will have no NULL element/IS NULL scan key */
893 : Assert(array->num_elems == -1);
894 36 : array->null_elem = false;
895 :
896 : /* IS NOT NULL key (could be leftarg or rightarg) now redundant */
897 36 : *result = true;
898 36 : return true;
899 : }
900 :
901 138 : if (leftarg->sk_flags & SK_ISNULL)
902 : {
903 : Assert(leftarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
904 6 : leftnull = true;
905 : }
906 : else
907 132 : leftnull = false;
908 138 : if (rightarg->sk_flags & SK_ISNULL)
909 : {
910 : Assert(rightarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
911 138 : rightnull = true;
912 : }
913 : else
914 0 : rightnull = false;
915 :
916 : /*
917 : * We treat NULL as either greater than or less than all other values.
918 : * Since true > false, the tests below work correctly for NULLS LAST
919 : * logic. If the index is NULLS FIRST, we need to flip the strategy.
920 : */
921 138 : strat = op->sk_strategy;
922 138 : if (op->sk_flags & SK_BT_NULLS_FIRST)
923 0 : strat = BTCommuteStrategyNumber(strat);
924 :
925 138 : switch (strat)
926 : {
927 132 : case BTLessStrategyNumber:
928 132 : *result = (leftnull < rightnull);
929 132 : break;
930 0 : case BTLessEqualStrategyNumber:
931 0 : *result = (leftnull <= rightnull);
932 0 : break;
933 6 : case BTEqualStrategyNumber:
934 6 : *result = (leftnull == rightnull);
935 6 : break;
936 0 : case BTGreaterEqualStrategyNumber:
937 0 : *result = (leftnull >= rightnull);
938 0 : break;
939 0 : case BTGreaterStrategyNumber:
940 0 : *result = (leftnull > rightnull);
941 0 : break;
942 0 : default:
943 0 : elog(ERROR, "unrecognized StrategyNumber: %d", (int) strat);
944 : *result = false; /* keep compiler quiet */
945 : break;
946 : }
947 138 : return true;
948 : }
949 :
950 : /*
951 : * We don't yet know how to determine redundancy when it involves a row
952 : * compare key (barring simple cases involving IS NULL/IS NOT NULL)
953 : */
954 450 : if ((leftarg->sk_flags | rightarg->sk_flags) & SK_ROW_HEADER)
955 : {
956 : Assert(!((leftarg->sk_flags | rightarg->sk_flags) & SK_BT_SKIP));
957 6 : return false;
958 : }
959 :
960 : /*
961 : * If either leftarg or rightarg are equality-type array scankeys, we need
962 : * specialized handling (since by now we know that IS NULL wasn't used)
963 : */
964 444 : if (array)
965 : {
966 : bool leftarray,
967 : rightarray;
968 :
969 620 : leftarray = ((leftarg->sk_flags & SK_SEARCHARRAY) &&
970 304 : leftarg->sk_strategy == BTEqualStrategyNumber);
971 328 : rightarray = ((rightarg->sk_flags & SK_SEARCHARRAY) &&
972 12 : rightarg->sk_strategy == BTEqualStrategyNumber);
973 :
974 : /*
975 : * _bt_preprocess_array_keys is responsible for merging together array
976 : * scan keys, and will do so whenever the opfamily has the required
977 : * cross-type support. If it failed to do that, we handle it just
978 : * like the case where we can't make the comparison ourselves.
979 : */
980 316 : if (leftarray && rightarray)
981 : {
982 : /* Can't make the comparison */
983 0 : *result = false; /* suppress compiler warnings */
984 : Assert(!((leftarg->sk_flags | rightarg->sk_flags) & SK_BT_SKIP));
985 0 : return false;
986 : }
987 :
988 : /*
989 : * Otherwise we need to determine if either one of leftarg or rightarg
990 : * uses an array, then pass this through to a dedicated helper
991 : * function.
992 : */
993 316 : if (leftarray)
994 304 : return _bt_compare_array_scankey_args(scan, leftarg, rightarg,
995 : orderproc, array, result);
996 12 : else if (rightarray)
997 12 : return _bt_compare_array_scankey_args(scan, rightarg, leftarg,
998 : orderproc, array, result);
999 :
1000 : /* FALL THRU */
1001 : }
1002 :
1003 : /*
1004 : * The opfamily we need to worry about is identified by the index column.
1005 : */
1006 : Assert(leftarg->sk_attno == rightarg->sk_attno);
1007 :
1008 128 : opcintype = rel->rd_opcintype[leftarg->sk_attno - 1];
1009 :
1010 : /*
1011 : * Determine the actual datatypes of the ScanKey arguments. We have to
1012 : * support the convention that sk_subtype == InvalidOid means the opclass
1013 : * input type; this is a hack to simplify life for ScanKeyInit().
1014 : */
1015 128 : lefttype = leftarg->sk_subtype;
1016 128 : if (lefttype == InvalidOid)
1017 0 : lefttype = opcintype;
1018 128 : righttype = rightarg->sk_subtype;
1019 128 : if (righttype == InvalidOid)
1020 0 : righttype = opcintype;
1021 128 : optype = op->sk_subtype;
1022 128 : if (optype == InvalidOid)
1023 0 : optype = opcintype;
1024 :
1025 : /*
1026 : * If leftarg and rightarg match the types expected for the "op" scankey,
1027 : * we can use its already-looked-up comparison function.
1028 : */
1029 128 : if (lefttype == opcintype && righttype == optype)
1030 : {
1031 122 : *result = DatumGetBool(FunctionCall2Coll(&op->sk_func,
1032 : op->sk_collation,
1033 : leftarg->sk_argument,
1034 : rightarg->sk_argument));
1035 122 : return true;
1036 : }
1037 :
1038 : /*
1039 : * Otherwise, we need to go to the syscache to find the appropriate
1040 : * operator. (This cannot result in infinite recursion, since no
1041 : * indexscan initiated by syscache lookup will use cross-data-type
1042 : * operators.)
1043 : *
1044 : * If the sk_strategy was flipped by _bt_fix_scankey_strategy, we have to
1045 : * un-flip it to get the correct opfamily member.
1046 : */
1047 6 : strat = op->sk_strategy;
1048 6 : if (op->sk_flags & SK_BT_DESC)
1049 0 : strat = BTCommuteStrategyNumber(strat);
1050 :
1051 6 : cmp_op = get_opfamily_member(rel->rd_opfamily[leftarg->sk_attno - 1],
1052 : lefttype,
1053 : righttype,
1054 : strat);
1055 6 : if (OidIsValid(cmp_op))
1056 : {
1057 6 : RegProcedure cmp_proc = get_opcode(cmp_op);
1058 :
1059 6 : if (RegProcedureIsValid(cmp_proc))
1060 : {
1061 6 : *result = DatumGetBool(OidFunctionCall2Coll(cmp_proc,
1062 : op->sk_collation,
1063 : leftarg->sk_argument,
1064 : rightarg->sk_argument));
1065 6 : return true;
1066 : }
1067 : }
1068 :
1069 : /* Can't make the comparison */
1070 0 : *result = false; /* suppress compiler warnings */
1071 0 : return false;
1072 : }
1073 :
1074 : /*
1075 : * Compare an array scan key to a scalar scan key, eliminating contradictory
1076 : * array elements such that the scalar scan key becomes redundant.
1077 : *
1078 : * If the opfamily is incomplete we may not be able to determine which
1079 : * elements are contradictory. When we return true we'll have validly set
1080 : * *qual_ok, guaranteeing that at least the scalar scan key can be considered
1081 : * redundant. We return false if the comparison could not be made (caller
1082 : * must keep both scan keys when this happens).
1083 : *
1084 : * Note: it's up to caller to deal with IS [NOT] NULL scan keys, as well as
1085 : * row comparison scan keys. We only deal with scalar scan keys.
1086 : */
1087 : static bool
1088 316 : _bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey,
1089 : FmgrInfo *orderproc, BTArrayKeyInfo *array,
1090 : bool *qual_ok)
1091 : {
1092 : Assert(arraysk->sk_attno == skey->sk_attno);
1093 : Assert(!(arraysk->sk_flags & (SK_ISNULL | SK_ROW_HEADER | SK_ROW_MEMBER)));
1094 : Assert((arraysk->sk_flags & SK_SEARCHARRAY) &&
1095 : arraysk->sk_strategy == BTEqualStrategyNumber);
1096 : /* don't expect to have to deal with NULLs/row comparison scan keys */
1097 : Assert(!(skey->sk_flags & (SK_ISNULL | SK_ROW_HEADER | SK_ROW_MEMBER)));
1098 : Assert(!(skey->sk_flags & SK_SEARCHARRAY) ||
1099 : skey->sk_strategy != BTEqualStrategyNumber);
1100 :
1101 : /*
1102 : * Just call the appropriate helper function based on whether it's a SAOP
1103 : * array or a skip array. Both helpers will set *qual_ok in passing.
1104 : */
1105 316 : if (array->num_elems != -1)
1106 30 : return _bt_saoparray_shrink(scan, arraysk, skey, orderproc, array,
1107 : qual_ok);
1108 : else
1109 286 : return _bt_skiparray_shrink(scan, skey, array, qual_ok);
1110 : }
1111 :
1112 : /*
1113 : * Preprocessing of SAOP array scan key, used to determine which array
1114 : * elements are eliminated as contradictory by a non-array scalar key.
1115 : *
1116 : * _bt_compare_array_scankey_args helper function.
1117 : *
1118 : * Array elements can be eliminated as contradictory when excluded by some
1119 : * other operator on the same attribute. For example, with an index scan qual
1120 : * "WHERE a IN (1, 2, 3) AND a < 2", all array elements except the value "1"
1121 : * are eliminated, and the < scan key is eliminated as redundant. Cases where
1122 : * every array element is eliminated by a redundant scalar scan key have an
1123 : * unsatisfiable qual, which we handle by setting *qual_ok=false for caller.
1124 : */
1125 : static bool
1126 30 : _bt_saoparray_shrink(IndexScanDesc scan, ScanKey arraysk, ScanKey skey,
1127 : FmgrInfo *orderproc, BTArrayKeyInfo *array, bool *qual_ok)
1128 : {
1129 30 : Relation rel = scan->indexRelation;
1130 30 : Oid opcintype = rel->rd_opcintype[arraysk->sk_attno - 1];
1131 30 : int cmpresult = 0,
1132 30 : cmpexact = 0,
1133 : matchelem,
1134 30 : new_nelems = 0;
1135 : FmgrInfo crosstypeproc;
1136 30 : FmgrInfo *orderprocp = orderproc;
1137 :
1138 : Assert(array->num_elems > 0);
1139 : Assert(!(arraysk->sk_flags & SK_BT_SKIP));
1140 :
1141 : /*
1142 : * _bt_binsrch_array_skey searches an array for the entry best matching a
1143 : * datum of opclass input type for the index's attribute (on-disk type).
1144 : * We can reuse the array's ORDER proc whenever the non-array scan key's
1145 : * type is a match for the corresponding attribute's input opclass type.
1146 : * Otherwise, we have to do another ORDER proc lookup so that our call to
1147 : * _bt_binsrch_array_skey applies the correct comparator.
1148 : *
1149 : * Note: we have to support the convention that sk_subtype == InvalidOid
1150 : * means the opclass input type; this is a hack to simplify life for
1151 : * ScanKeyInit().
1152 : */
1153 30 : if (skey->sk_subtype != opcintype && skey->sk_subtype != InvalidOid)
1154 : {
1155 : RegProcedure cmp_proc;
1156 : Oid arraysk_elemtype;
1157 :
1158 : /*
1159 : * Need an ORDER proc lookup to detect redundancy/contradictoriness
1160 : * with this pair of scankeys.
1161 : *
1162 : * Scalar scan key's argument will be passed to _bt_compare_array_skey
1163 : * as its tupdatum/lefthand argument (rhs arg is for array elements).
1164 : */
1165 6 : arraysk_elemtype = arraysk->sk_subtype;
1166 6 : if (arraysk_elemtype == InvalidOid)
1167 0 : arraysk_elemtype = rel->rd_opcintype[arraysk->sk_attno - 1];
1168 6 : cmp_proc = get_opfamily_proc(rel->rd_opfamily[arraysk->sk_attno - 1],
1169 : skey->sk_subtype, arraysk_elemtype,
1170 : BTORDER_PROC);
1171 6 : if (!RegProcedureIsValid(cmp_proc))
1172 : {
1173 : /* Can't make the comparison */
1174 0 : *qual_ok = false; /* suppress compiler warnings */
1175 0 : return false;
1176 : }
1177 :
1178 : /* We have all we need to determine redundancy/contradictoriness */
1179 6 : orderprocp = &crosstypeproc;
1180 6 : fmgr_info(cmp_proc, orderprocp);
1181 : }
1182 :
1183 30 : matchelem = _bt_binsrch_array_skey(orderprocp, false,
1184 : NoMovementScanDirection,
1185 : skey->sk_argument, false, array,
1186 : arraysk, &cmpresult);
1187 :
1188 30 : switch (skey->sk_strategy)
1189 : {
1190 6 : case BTLessStrategyNumber:
1191 6 : cmpexact = 1; /* exclude exact match, if any */
1192 : /* FALL THRU */
1193 6 : case BTLessEqualStrategyNumber:
1194 6 : if (cmpresult >= cmpexact)
1195 0 : matchelem++;
1196 : /* Resize, keeping elements from the start of the array */
1197 6 : new_nelems = matchelem;
1198 6 : break;
1199 12 : case BTEqualStrategyNumber:
1200 12 : if (cmpresult != 0)
1201 : {
1202 : /* qual is unsatisfiable */
1203 6 : new_nelems = 0;
1204 : }
1205 : else
1206 : {
1207 : /* Shift matching element to the start of the array, resize */
1208 6 : array->elem_values[0] = array->elem_values[matchelem];
1209 6 : new_nelems = 1;
1210 : }
1211 12 : break;
1212 6 : case BTGreaterEqualStrategyNumber:
1213 6 : cmpexact = 1; /* include exact match, if any */
1214 : /* FALL THRU */
1215 12 : case BTGreaterStrategyNumber:
1216 12 : if (cmpresult >= cmpexact)
1217 6 : matchelem++;
1218 : /* Shift matching elements to the start of the array, resize */
1219 12 : new_nelems = array->num_elems - matchelem;
1220 12 : memmove(array->elem_values, array->elem_values + matchelem,
1221 : sizeof(Datum) * new_nelems);
1222 12 : break;
1223 0 : default:
1224 0 : elog(ERROR, "unrecognized StrategyNumber: %d",
1225 : (int) skey->sk_strategy);
1226 : break;
1227 : }
1228 :
1229 : Assert(new_nelems >= 0);
1230 : Assert(new_nelems <= array->num_elems);
1231 :
1232 30 : array->num_elems = new_nelems;
1233 30 : *qual_ok = new_nelems > 0;
1234 :
1235 30 : return true;
1236 : }
1237 :
1238 : /*
1239 : * Preprocessing of skip array scan key, used to determine redundancy against
1240 : * a non-array scalar scan key (must be an inequality).
1241 : *
1242 : * _bt_compare_array_scankey_args helper function.
1243 : *
1244 : * Skip arrays work by procedurally generating their elements as needed, so we
1245 : * just store the inequality as the skip array's low_compare or high_compare
1246 : * (except when there's already a more restrictive low_compare/high_compare).
1247 : * The array's final elements are the range of values that still satisfy the
1248 : * array's final low_compare and high_compare.
1249 : */
1250 : static bool
1251 286 : _bt_skiparray_shrink(IndexScanDesc scan, ScanKey skey, BTArrayKeyInfo *array,
1252 : bool *qual_ok)
1253 : {
1254 : bool test_result;
1255 :
1256 : Assert(array->num_elems == -1);
1257 :
1258 : /*
1259 : * Array's index attribute will be constrained by a strict operator/key.
1260 : * Array must not "contain a NULL element" (i.e. the scan must not apply
1261 : * "IS NULL" qual when it reaches the end of the index that stores NULLs).
1262 : */
1263 286 : array->null_elem = false;
1264 286 : *qual_ok = true;
1265 :
1266 : /*
1267 : * Consider if we should treat caller's scalar scan key as the skip
1268 : * array's high_compare or low_compare.
1269 : *
1270 : * In general the current array element must either be a copy of a value
1271 : * taken from an index tuple, or a derivative value generated by opclass's
1272 : * skip support function. That way the scan can always safely assume that
1273 : * it's okay to use the only-input-opclass-type proc from so->orderProcs[]
1274 : * (they can be cross-type with SAOP arrays, but never with skip arrays).
1275 : *
1276 : * This approach is enabled by MINVAL/MAXVAL sentinel key markings, which
1277 : * can be thought of as representing either the lowest or highest matching
1278 : * array element (excluding the NULL element, where applicable, though as
1279 : * just discussed it isn't applicable to this range skip array anyway).
1280 : * Array keys marked MINVAL/MAXVAL never have a valid datum in their
1281 : * sk_argument field. The scan directly applies the array's low_compare
1282 : * key when it encounters MINVAL in the array key proper (just as it
1283 : * applies high_compare when it sees MAXVAL set in the array key proper).
1284 : * The scan must never use the array's so->orderProcs[] proc against
1285 : * low_compare's/high_compare's sk_argument, either (so->orderProcs[] is
1286 : * only intended to be used with rhs datums from the array proper/index).
1287 : */
1288 286 : switch (skey->sk_strategy)
1289 : {
1290 146 : case BTLessStrategyNumber:
1291 : case BTLessEqualStrategyNumber:
1292 146 : if (array->high_compare)
1293 : {
1294 : /* replace existing high_compare with caller's key? */
1295 6 : if (!_bt_compare_scankey_args(scan, array->high_compare, skey,
1296 : array->high_compare, NULL, NULL,
1297 : &test_result))
1298 0 : return false; /* can't determine more restrictive key */
1299 :
1300 6 : if (!test_result)
1301 6 : return true; /* no, just discard caller's key */
1302 :
1303 : /* yes, replace existing high_compare with caller's key */
1304 : }
1305 :
1306 : /* caller's key becomes skip array's high_compare */
1307 140 : array->high_compare = skey;
1308 140 : break;
1309 140 : case BTGreaterEqualStrategyNumber:
1310 : case BTGreaterStrategyNumber:
1311 140 : if (array->low_compare)
1312 : {
1313 : /* replace existing low_compare with caller's key? */
1314 6 : if (!_bt_compare_scankey_args(scan, array->low_compare, skey,
1315 : array->low_compare, NULL, NULL,
1316 : &test_result))
1317 0 : return false; /* can't determine more restrictive key */
1318 :
1319 6 : if (!test_result)
1320 0 : return true; /* no, just discard caller's key */
1321 :
1322 : /* yes, replace existing low_compare with caller's key */
1323 : }
1324 :
1325 : /* caller's key becomes skip array's low_compare */
1326 140 : array->low_compare = skey;
1327 140 : break;
1328 0 : case BTEqualStrategyNumber:
1329 : default:
1330 0 : elog(ERROR, "unrecognized StrategyNumber: %d",
1331 : (int) skey->sk_strategy);
1332 : break;
1333 : }
1334 :
1335 280 : return true;
1336 : }
1337 :
1338 : /*
1339 : * Applies the opfamily's skip support routine to convert the skip array's >
1340 : * low_compare key (if any) into a >= key, and to convert its < high_compare
1341 : * key (if any) into a <= key. Decrements the high_compare key's sk_argument,
1342 : * and/or increments the low_compare key's sk_argument (also adjusts their
1343 : * operator strategies, while changing the operator as appropriate).
1344 : *
1345 : * This optional optimization reduces the number of descents required within
1346 : * _bt_first. Whenever _bt_first is called with a skip array whose current
1347 : * array element is the sentinel value MINVAL, using a transformed >= key
1348 : * instead of using the original > key makes it safe to include lower-order
1349 : * scan keys in the insertion scan key (there must be lower-order scan keys
1350 : * after the skip array). We will avoid an extra _bt_first to find the first
1351 : * value in the index > sk_argument -- at least when the first real matching
1352 : * value in the index happens to be an exact match for the sk_argument value
1353 : * that we produced here by incrementing the original input key's sk_argument.
1354 : * (Backwards scans derive the same benefit when they encounter the sentinel
1355 : * value MAXVAL, by converting the high_compare key from < to <=.)
1356 : *
1357 : * Note: The transformation is only correct when it cannot allow the scan to
1358 : * overlook matching tuples, but we don't have enough semantic information to
1359 : * safely make sure that can't happen during scans with cross-type operators.
1360 : * That's why we'll never apply the transformation in cross-type scenarios.
1361 : * For example, if we attempted to convert "sales_ts > '2024-01-01'::date"
1362 : * into "sales_ts >= '2024-01-02'::date" given a "sales_ts" attribute whose
1363 : * input opclass is timestamp_ops, the scan would overlook almost all (or all)
1364 : * tuples for sales that fell on '2024-01-01'.
1365 : *
1366 : * Note: We can safely modify array->low_compare/array->high_compare in place
1367 : * because they just point to copies of our scan->keyData[] input scan keys
1368 : * (namely the copies returned by _bt_preprocess_array_keys to be used as
1369 : * input into the standard preprocessing steps in _bt_preprocess_keys).
1370 : * Everything will be reset if there's a rescan.
1371 : */
1372 : static void
1373 78 : _bt_skiparray_strat_adjust(IndexScanDesc scan, ScanKey arraysk,
1374 : BTArrayKeyInfo *array)
1375 : {
1376 78 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1377 : MemoryContext oldContext;
1378 :
1379 : /*
1380 : * Called last among all preprocessing steps, when the skip array's final
1381 : * low_compare and high_compare have both been chosen
1382 : */
1383 : Assert(arraysk->sk_flags & SK_BT_SKIP);
1384 : Assert(array->num_elems == -1 && !array->null_elem && array->sksup);
1385 :
1386 78 : oldContext = MemoryContextSwitchTo(so->arrayContext);
1387 :
1388 78 : if (array->high_compare &&
1389 24 : array->high_compare->sk_strategy == BTLessStrategyNumber)
1390 18 : _bt_skiparray_strat_decrement(scan, arraysk, array);
1391 :
1392 78 : if (array->low_compare &&
1393 18 : array->low_compare->sk_strategy == BTGreaterStrategyNumber)
1394 12 : _bt_skiparray_strat_increment(scan, arraysk, array);
1395 :
1396 78 : MemoryContextSwitchTo(oldContext);
1397 78 : }
1398 :
1399 : /*
1400 : * Convert skip array's > low_compare key into a >= key
1401 : */
1402 : static void
1403 18 : _bt_skiparray_strat_decrement(IndexScanDesc scan, ScanKey arraysk,
1404 : BTArrayKeyInfo *array)
1405 : {
1406 18 : Relation rel = scan->indexRelation;
1407 18 : Oid opfamily = rel->rd_opfamily[arraysk->sk_attno - 1],
1408 18 : opcintype = rel->rd_opcintype[arraysk->sk_attno - 1],
1409 : leop;
1410 : RegProcedure cmp_proc;
1411 18 : ScanKey high_compare = array->high_compare;
1412 18 : Datum orig_sk_argument = high_compare->sk_argument,
1413 : new_sk_argument;
1414 : bool uflow;
1415 : int16 lookupstrat;
1416 :
1417 : Assert(high_compare->sk_strategy == BTLessStrategyNumber);
1418 :
1419 : /*
1420 : * Only perform the transformation when the operator type matches the
1421 : * index attribute's input opclass type
1422 : */
1423 18 : if (high_compare->sk_subtype != opcintype &&
1424 0 : high_compare->sk_subtype != InvalidOid)
1425 0 : return;
1426 :
1427 : /* Decrement, handling underflow by marking the qual unsatisfiable */
1428 18 : new_sk_argument = array->sksup->decrement(rel, orig_sk_argument, &uflow);
1429 18 : if (uflow)
1430 : {
1431 0 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1432 :
1433 0 : so->qual_ok = false;
1434 0 : return;
1435 : }
1436 :
1437 : /*
1438 : * Look up <= operator (might fail), accounting for the fact that a
1439 : * high_compare on a DESC column already had its strategy commuted
1440 : */
1441 18 : lookupstrat = BTLessEqualStrategyNumber;
1442 18 : if (high_compare->sk_flags & SK_BT_DESC)
1443 0 : lookupstrat = BTGreaterEqualStrategyNumber; /* commute this too */
1444 18 : leop = get_opfamily_member(opfamily, opcintype, opcintype, lookupstrat);
1445 18 : if (!OidIsValid(leop))
1446 0 : return;
1447 18 : cmp_proc = get_opcode(leop);
1448 18 : if (RegProcedureIsValid(cmp_proc))
1449 : {
1450 : /* Transform < high_compare key into <= key */
1451 18 : fmgr_info(cmp_proc, &high_compare->sk_func);
1452 18 : high_compare->sk_argument = new_sk_argument;
1453 18 : high_compare->sk_strategy = BTLessEqualStrategyNumber;
1454 : }
1455 : }
1456 :
1457 : /*
1458 : * Convert skip array's < low_compare key into a <= key
1459 : */
1460 : static void
1461 12 : _bt_skiparray_strat_increment(IndexScanDesc scan, ScanKey arraysk,
1462 : BTArrayKeyInfo *array)
1463 : {
1464 12 : Relation rel = scan->indexRelation;
1465 12 : Oid opfamily = rel->rd_opfamily[arraysk->sk_attno - 1],
1466 12 : opcintype = rel->rd_opcintype[arraysk->sk_attno - 1],
1467 : geop;
1468 : RegProcedure cmp_proc;
1469 12 : ScanKey low_compare = array->low_compare;
1470 12 : Datum orig_sk_argument = low_compare->sk_argument,
1471 : new_sk_argument;
1472 : bool oflow;
1473 : int16 lookupstrat;
1474 :
1475 : Assert(low_compare->sk_strategy == BTGreaterStrategyNumber);
1476 :
1477 : /*
1478 : * Only perform the transformation when the operator type matches the
1479 : * index attribute's input opclass type
1480 : */
1481 12 : if (low_compare->sk_subtype != opcintype &&
1482 0 : low_compare->sk_subtype != InvalidOid)
1483 0 : return;
1484 :
1485 : /* Increment, handling overflow by marking the qual unsatisfiable */
1486 12 : new_sk_argument = array->sksup->increment(rel, orig_sk_argument, &oflow);
1487 12 : if (oflow)
1488 : {
1489 0 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1490 :
1491 0 : so->qual_ok = false;
1492 0 : return;
1493 : }
1494 :
1495 : /*
1496 : * Look up >= operator (might fail), accounting for the fact that a
1497 : * low_compare on a DESC column already had its strategy commuted
1498 : */
1499 12 : lookupstrat = BTGreaterEqualStrategyNumber;
1500 12 : if (low_compare->sk_flags & SK_BT_DESC)
1501 0 : lookupstrat = BTLessEqualStrategyNumber; /* commute this too */
1502 12 : geop = get_opfamily_member(opfamily, opcintype, opcintype, lookupstrat);
1503 12 : if (!OidIsValid(geop))
1504 0 : return;
1505 12 : cmp_proc = get_opcode(geop);
1506 12 : if (RegProcedureIsValid(cmp_proc))
1507 : {
1508 : /* Transform > low_compare key into >= key */
1509 12 : fmgr_info(cmp_proc, &low_compare->sk_func);
1510 12 : low_compare->sk_argument = new_sk_argument;
1511 12 : low_compare->sk_strategy = BTGreaterEqualStrategyNumber;
1512 : }
1513 : }
1514 :
1515 : /*
1516 : * _bt_unmark_keys() -- make superfluous required keys nonrequired after all
1517 : *
1518 : * When _bt_preprocess_keys fails to eliminate one or more redundant keys, it
1519 : * calls here to make sure that no index attribute has more than one > or >=
1520 : * key marked required, and no more than one required < or <= key. Attributes
1521 : * with = keys will always get one = key as their required key. All other
1522 : * keys that were initially marked required get "unmarked" here. That way,
1523 : * _bt_first and _bt_checkkeys will reliably agree on which keys to use to
1524 : * start and/or to end the scan.
1525 : *
1526 : * We also relocate keys that become/started out nonrequired to the end of
1527 : * so->keyData[]. That way, _bt_first and _bt_checkkeys cannot fail to reach
1528 : * a required key due to some earlier nonrequired key getting in the way.
1529 : *
1530 : * Only call here when _bt_compare_scankey_args returned false at least once
1531 : * (otherwise, calling here will just waste cycles).
1532 : */
1533 : static void
1534 6 : _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap)
1535 : {
1536 6 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1537 : AttrNumber attno;
1538 : bool *unmarkikey;
1539 : int nunmark,
1540 : nunmarked,
1541 : nkept,
1542 : firsti;
1543 : ScanKey keepKeys,
1544 : unmarkKeys;
1545 6 : FmgrInfo *keepOrderProcs = NULL,
1546 6 : *unmarkOrderProcs = NULL;
1547 : bool haveReqEquals,
1548 : haveReqForward,
1549 : haveReqBackward;
1550 :
1551 : /*
1552 : * Do an initial pass over so->keyData[] that determines which keys to
1553 : * keep as required. We expect so->keyData[] to still be in attribute
1554 : * order when we're called (though we don't expect any particular order
1555 : * among each attribute's keys).
1556 : *
1557 : * When both equality and inequality keys remain on a single attribute, we
1558 : * *must* make sure that exactly one of the equalities remains required.
1559 : * Any requiredness markings that we might leave on later keys/attributes
1560 : * are predicated on there being required = keys on all prior columns.
1561 : */
1562 6 : unmarkikey = palloc0(so->numberOfKeys * sizeof(bool));
1563 6 : nunmark = 0;
1564 :
1565 : /* Set things up for first key's attribute */
1566 6 : attno = so->keyData[0].sk_attno;
1567 6 : firsti = 0;
1568 6 : haveReqEquals = false;
1569 6 : haveReqForward = false;
1570 6 : haveReqBackward = false;
1571 30 : for (int i = 0; i < so->numberOfKeys; i++)
1572 : {
1573 24 : ScanKey origkey = &so->keyData[i];
1574 :
1575 24 : if (origkey->sk_attno != attno)
1576 : {
1577 : /* Reset for next attribute */
1578 12 : attno = origkey->sk_attno;
1579 12 : firsti = i;
1580 :
1581 12 : haveReqEquals = false;
1582 12 : haveReqForward = false;
1583 12 : haveReqBackward = false;
1584 : }
1585 :
1586 : /* Equalities get priority over inequalities */
1587 24 : if (haveReqEquals)
1588 : {
1589 : /*
1590 : * We already found the first "=" key for this attribute. We've
1591 : * already decided that all its other keys will be unmarked.
1592 : */
1593 : Assert(!(origkey->sk_flags & SK_SEARCHNULL));
1594 0 : unmarkikey[i] = true;
1595 0 : nunmark++;
1596 0 : continue;
1597 : }
1598 24 : else if ((origkey->sk_flags & SK_BT_REQFWD) &&
1599 18 : (origkey->sk_flags & SK_BT_REQBKWD))
1600 : {
1601 : /*
1602 : * Found the first "=" key for attno. All other attno keys will
1603 : * be unmarked.
1604 : */
1605 : Assert(origkey->sk_strategy == BTEqualStrategyNumber);
1606 :
1607 18 : haveReqEquals = true;
1608 24 : for (int j = firsti; j < i; j++)
1609 : {
1610 : /* Unmark any prior inequality keys on attno after all */
1611 6 : if (!unmarkikey[j])
1612 : {
1613 6 : unmarkikey[j] = true;
1614 6 : nunmark++;
1615 : }
1616 : }
1617 18 : continue;
1618 : }
1619 :
1620 : /* Deal with inequalities next */
1621 6 : if ((origkey->sk_flags & SK_BT_REQFWD) && !haveReqForward)
1622 : {
1623 0 : haveReqForward = true;
1624 0 : continue;
1625 : }
1626 6 : else if ((origkey->sk_flags & SK_BT_REQBKWD) && !haveReqBackward)
1627 : {
1628 6 : haveReqBackward = true;
1629 6 : continue;
1630 : }
1631 :
1632 : /*
1633 : * We have either a redundant inequality key that will be unmarked, or
1634 : * we have a key that wasn't marked required in the first place
1635 : */
1636 0 : unmarkikey[i] = true;
1637 0 : nunmark++;
1638 : }
1639 :
1640 : /* Should only be called when _bt_compare_scankey_args reported failure */
1641 : Assert(nunmark > 0);
1642 :
1643 : /*
1644 : * Next, allocate temp arrays: one for required keys that'll remain
1645 : * required, the other for all remaining keys
1646 : */
1647 6 : unmarkKeys = palloc(nunmark * sizeof(ScanKeyData));
1648 6 : keepKeys = palloc((so->numberOfKeys - nunmark) * sizeof(ScanKeyData));
1649 6 : nunmarked = 0;
1650 6 : nkept = 0;
1651 6 : if (so->numArrayKeys)
1652 : {
1653 6 : unmarkOrderProcs = palloc(nunmark * sizeof(FmgrInfo));
1654 6 : keepOrderProcs = palloc((so->numberOfKeys - nunmark) * sizeof(FmgrInfo));
1655 : }
1656 :
1657 : /*
1658 : * Next, copy the contents of so->keyData[] into the appropriate temp
1659 : * array.
1660 : *
1661 : * Scans with = array keys need us to maintain invariants around the order
1662 : * of so->orderProcs[] and so->arrayKeys[] relative to so->keyData[]. See
1663 : * _bt_preprocess_array_keys_final for a full explanation.
1664 : */
1665 30 : for (int i = 0; i < so->numberOfKeys; i++)
1666 : {
1667 24 : ScanKey origkey = &so->keyData[i];
1668 : ScanKey unmark;
1669 :
1670 24 : if (!unmarkikey[i])
1671 : {
1672 : /*
1673 : * Key gets to keep its original requiredness markings.
1674 : *
1675 : * Key will stay in its original position, unless we're going to
1676 : * unmark an earlier key (in which case this key gets moved back).
1677 : */
1678 18 : memcpy(keepKeys + nkept, origkey, sizeof(ScanKeyData));
1679 :
1680 18 : if (so->numArrayKeys)
1681 : {
1682 18 : keyDataMap[i] = nkept;
1683 18 : memcpy(keepOrderProcs + nkept, &so->orderProcs[i],
1684 : sizeof(FmgrInfo));
1685 : }
1686 :
1687 18 : nkept++;
1688 18 : continue;
1689 : }
1690 :
1691 : /*
1692 : * Key will be unmarked as needed, and moved to the end of the array,
1693 : * next to other keys that will become (or always were) nonrequired
1694 : */
1695 6 : unmark = unmarkKeys + nunmarked;
1696 6 : memcpy(unmark, origkey, sizeof(ScanKeyData));
1697 :
1698 6 : if (so->numArrayKeys)
1699 : {
1700 6 : keyDataMap[i] = (so->numberOfKeys - nunmark) + nunmarked;
1701 6 : memcpy(&unmarkOrderProcs[nunmarked], &so->orderProcs[i],
1702 : sizeof(FmgrInfo));
1703 : }
1704 :
1705 : /*
1706 : * Preprocessing only generates skip arrays when it knows that they'll
1707 : * be the only required = key on the attr. We'll never unmark them.
1708 : */
1709 : Assert(!(unmark->sk_flags & SK_BT_SKIP));
1710 :
1711 : /*
1712 : * Also shouldn't have to unmark an IS NULL or an IS NOT NULL key.
1713 : * They aren't cross-type, so an incomplete opfamily can't matter.
1714 : */
1715 : Assert(!(unmark->sk_flags & SK_ISNULL) ||
1716 : !(unmark->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)));
1717 :
1718 : /* Clear requiredness flags on redundant key (and on any subkeys) */
1719 6 : unmark->sk_flags &= ~(SK_BT_REQFWD | SK_BT_REQBKWD);
1720 6 : if (unmark->sk_flags & SK_ROW_HEADER)
1721 : {
1722 6 : ScanKey subkey = (ScanKey) DatumGetPointer(unmark->sk_argument);
1723 :
1724 : Assert(subkey->sk_strategy == unmark->sk_strategy);
1725 : for (;;)
1726 : {
1727 6 : Assert(subkey->sk_flags & SK_ROW_MEMBER);
1728 12 : subkey->sk_flags &= ~(SK_BT_REQFWD | SK_BT_REQBKWD);
1729 12 : if (subkey->sk_flags & SK_ROW_END)
1730 6 : break;
1731 6 : subkey++;
1732 : }
1733 : }
1734 :
1735 6 : nunmarked++;
1736 : }
1737 :
1738 : /* Copy both temp arrays back into so->keyData[] to reorder */
1739 : Assert(nkept == so->numberOfKeys - nunmark);
1740 : Assert(nunmarked == nunmark);
1741 6 : memcpy(so->keyData, keepKeys, sizeof(ScanKeyData) * nkept);
1742 6 : memcpy(so->keyData + nkept, unmarkKeys, sizeof(ScanKeyData) * nunmarked);
1743 :
1744 : /* Done with temp arrays */
1745 6 : pfree(unmarkikey);
1746 6 : pfree(keepKeys);
1747 6 : pfree(unmarkKeys);
1748 :
1749 : /*
1750 : * Now copy so->orderProcs[] temp entries needed by scans with = array
1751 : * keys back (just like with the so->keyData[] temp arrays)
1752 : */
1753 6 : if (so->numArrayKeys)
1754 : {
1755 6 : memcpy(so->orderProcs, keepOrderProcs, sizeof(FmgrInfo) * nkept);
1756 6 : memcpy(so->orderProcs + nkept, unmarkOrderProcs,
1757 : sizeof(FmgrInfo) * nunmarked);
1758 :
1759 : /* Also fix-up array->scan_key references */
1760 18 : for (int arridx = 0; arridx < so->numArrayKeys; arridx++)
1761 : {
1762 12 : BTArrayKeyInfo *array = &so->arrayKeys[arridx];
1763 :
1764 12 : array->scan_key = keyDataMap[array->scan_key];
1765 : }
1766 :
1767 : /*
1768 : * Sort so->arrayKeys[] based on its new BTArrayKeyInfo.scan_key
1769 : * offsets, so that its order matches so->keyData[] order as expected
1770 : */
1771 6 : qsort(so->arrayKeys, so->numArrayKeys, sizeof(BTArrayKeyInfo),
1772 : _bt_reorder_array_cmp);
1773 :
1774 : /* Done with temp arrays */
1775 6 : pfree(unmarkOrderProcs);
1776 6 : pfree(keepOrderProcs);
1777 : }
1778 6 : }
1779 :
1780 : /*
1781 : * qsort comparator for reordering so->arrayKeys[] BTArrayKeyInfo entries
1782 : */
1783 : static int
1784 6 : _bt_reorder_array_cmp(const void *a, const void *b)
1785 : {
1786 6 : BTArrayKeyInfo *arraya = (BTArrayKeyInfo *) a;
1787 6 : BTArrayKeyInfo *arrayb = (BTArrayKeyInfo *) b;
1788 :
1789 6 : return pg_cmp_s32(arraya->scan_key, arrayb->scan_key);
1790 : }
1791 :
1792 : /*
1793 : * _bt_preprocess_array_keys() -- Preprocess SK_SEARCHARRAY scan keys
1794 : *
1795 : * If there are any SK_SEARCHARRAY scan keys, deconstruct the array(s) and
1796 : * set up BTArrayKeyInfo info for each one that is an equality-type key.
1797 : * Returns modified scan keys as input for further, standard preprocessing.
1798 : *
1799 : * Currently we perform two kinds of preprocessing to deal with redundancies.
1800 : * For inequality array keys, it's sufficient to find the extreme element
1801 : * value and replace the whole array with that scalar value. This eliminates
1802 : * all but one array element as redundant. Similarly, we are capable of
1803 : * "merging together" multiple equality array keys (from two or more input
1804 : * scan keys) into a single output scan key containing only the intersecting
1805 : * array elements. This can eliminate many redundant array elements, as well
1806 : * as eliminating whole array scan keys as redundant. It can also allow us to
1807 : * detect contradictory quals.
1808 : *
1809 : * Caller must pass *new_numberOfKeys to give us a way to change the number of
1810 : * scan keys that caller treats as input to standard preprocessing steps. The
1811 : * returned array is smaller than scan->keyData[] when we could eliminate a
1812 : * redundant array scan key (redundant with another array scan key). It is
1813 : * convenient for _bt_preprocess_keys caller to have to deal with no more than
1814 : * one equality strategy array scan key per index attribute. We'll always be
1815 : * able to set things up that way when complete opfamilies are used.
1816 : *
1817 : * We're also responsible for generating skip arrays (and their associated
1818 : * scan keys) here. This enables skip scan. We do this for index attributes
1819 : * that initially lacked an equality condition within scan->keyData[], iff
1820 : * doing so allows a later scan key (that was passed to us in scan->keyData[])
1821 : * to be marked required by our _bt_preprocess_keys caller.
1822 : *
1823 : * We set the scan key references from the scan's BTArrayKeyInfo info array to
1824 : * offsets into the temp modified input array returned to caller. Scans that
1825 : * have array keys should call _bt_preprocess_array_keys_final when standard
1826 : * preprocessing steps are complete. This will convert the scan key offset
1827 : * references into references to the scan's so->keyData[] output scan keys.
1828 : *
1829 : * Note: the reason we need to return a temp scan key array, rather than just
1830 : * modifying scan->keyData[], is that callers are permitted to call btrescan
1831 : * without supplying a new set of scankey data. Certain other preprocessing
1832 : * routines (e.g., _bt_fix_scankey_strategy) _can_ modify scan->keyData[], but
1833 : * we can't make that work here because our modifications are non-idempotent.
1834 : */
1835 : static ScanKey
1836 16396512 : _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
1837 : {
1838 16396512 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1839 16396512 : Relation rel = scan->indexRelation;
1840 16396512 : int16 *indoption = rel->rd_indoption;
1841 : Oid skip_eq_ops[INDEX_MAX_KEYS];
1842 : int numArrayKeys,
1843 : numSkipArrayKeys,
1844 : numArrayKeyData;
1845 16396512 : AttrNumber attno_skip = 1;
1846 16396512 : int origarrayatt = InvalidAttrNumber,
1847 16396512 : origarraykey = -1;
1848 16396512 : Oid origelemtype = InvalidOid;
1849 : MemoryContext oldContext;
1850 : ScanKey arrayKeyData; /* modified copy of scan->keyData */
1851 :
1852 : /*
1853 : * Check the number of input array keys within scan->keyData[] input keys
1854 : * (also checks if we should add extra skip arrays based on input keys)
1855 : */
1856 16396512 : numArrayKeys = _bt_num_array_keys(scan, skip_eq_ops, &numSkipArrayKeys);
1857 16396512 : so->skipScan = (numSkipArrayKeys > 0);
1858 :
1859 : /* Quit if nothing to do. */
1860 16396512 : if (numArrayKeys == 0)
1861 16325144 : return NULL;
1862 :
1863 : /*
1864 : * Estimated final size of arrayKeyData[] array we'll return to our caller
1865 : * is the size of the original scan->keyData[] input array, plus space for
1866 : * any additional skip array scan keys we'll need to generate below
1867 : */
1868 71368 : numArrayKeyData = scan->numberOfKeys + numSkipArrayKeys;
1869 :
1870 : /*
1871 : * Make a scan-lifespan context to hold array-associated data, or reset it
1872 : * if we already have one from a previous rescan cycle.
1873 : */
1874 71368 : if (so->arrayContext == NULL)
1875 4784 : so->arrayContext = AllocSetContextCreate(CurrentMemoryContext,
1876 : "BTree array context",
1877 : ALLOCSET_SMALL_SIZES);
1878 : else
1879 66584 : MemoryContextReset(so->arrayContext);
1880 :
1881 71368 : oldContext = MemoryContextSwitchTo(so->arrayContext);
1882 :
1883 : /* Create output scan keys in the workspace context */
1884 71368 : arrayKeyData = (ScanKey) palloc(numArrayKeyData * sizeof(ScanKeyData));
1885 :
1886 : /* Allocate space for per-array data in the workspace context */
1887 71368 : so->arrayKeys = (BTArrayKeyInfo *) palloc(numArrayKeys * sizeof(BTArrayKeyInfo));
1888 :
1889 : /* Allocate space for ORDER procs used to help _bt_checkkeys */
1890 71368 : so->orderProcs = (FmgrInfo *) palloc(numArrayKeyData * sizeof(FmgrInfo));
1891 :
1892 71368 : numArrayKeys = 0;
1893 71368 : numArrayKeyData = 0;
1894 144528 : for (int input_ikey = 0; input_ikey < scan->numberOfKeys; input_ikey++)
1895 : {
1896 73178 : ScanKey inkey = scan->keyData + input_ikey,
1897 : cur;
1898 : FmgrInfo sortproc;
1899 73178 : FmgrInfo *sortprocp = &sortproc;
1900 : Oid elemtype;
1901 : bool reverse;
1902 : ArrayType *arrayval;
1903 : int16 elmlen;
1904 : bool elmbyval;
1905 : char elmalign;
1906 : int num_elems;
1907 : Datum *elem_values;
1908 : bool *elem_nulls;
1909 : int num_nonnulls;
1910 :
1911 : /* set up next output scan key */
1912 73178 : cur = &arrayKeyData[numArrayKeyData];
1913 :
1914 : /* Backfill skip arrays for attrs < or <= input key's attr? */
1915 76998 : while (numSkipArrayKeys && attno_skip <= inkey->sk_attno)
1916 : {
1917 4648 : Oid opfamily = rel->rd_opfamily[attno_skip - 1];
1918 4648 : Oid opcintype = rel->rd_opcintype[attno_skip - 1];
1919 4648 : Oid collation = rel->rd_indcollation[attno_skip - 1];
1920 4648 : Oid eq_op = skip_eq_ops[attno_skip - 1];
1921 : CompactAttribute *attr;
1922 : RegProcedure cmp_proc;
1923 :
1924 4648 : if (!OidIsValid(eq_op))
1925 : {
1926 : /*
1927 : * Attribute already has an = input key, so don't output a
1928 : * skip array for attno_skip. Just copy attribute's = input
1929 : * key into arrayKeyData[] once outside this inner loop.
1930 : *
1931 : * Note: When we get here there must be a later attribute that
1932 : * lacks an equality input key, and still needs a skip array
1933 : * (if there wasn't then numSkipArrayKeys would be 0 by now).
1934 : */
1935 : Assert(attno_skip == inkey->sk_attno);
1936 : /* inkey can't be last input key to be marked required: */
1937 : Assert(input_ikey < scan->numberOfKeys - 1);
1938 : #if 0
1939 : /* Could be a redundant input scan key, so can't do this: */
1940 : Assert(inkey->sk_strategy == BTEqualStrategyNumber ||
1941 : (inkey->sk_flags & SK_SEARCHNULL));
1942 : #endif
1943 :
1944 828 : attno_skip++;
1945 828 : break;
1946 : }
1947 :
1948 3820 : cmp_proc = get_opcode(eq_op);
1949 3820 : if (!RegProcedureIsValid(cmp_proc))
1950 0 : elog(ERROR, "missing oprcode for skipping equals operator %u", eq_op);
1951 :
1952 3820 : ScanKeyEntryInitialize(cur,
1953 : SK_SEARCHARRAY | SK_BT_SKIP, /* flags */
1954 : attno_skip, /* skipped att number */
1955 : BTEqualStrategyNumber, /* equality strategy */
1956 : InvalidOid, /* opclass input subtype */
1957 : collation, /* index column's collation */
1958 : cmp_proc, /* equality operator's proc */
1959 : (Datum) 0); /* constant */
1960 :
1961 : /* Initialize generic BTArrayKeyInfo fields */
1962 3820 : so->arrayKeys[numArrayKeys].scan_key = numArrayKeyData;
1963 3820 : so->arrayKeys[numArrayKeys].num_elems = -1;
1964 :
1965 : /* Initialize skip array specific BTArrayKeyInfo fields */
1966 3820 : attr = TupleDescCompactAttr(RelationGetDescr(rel), attno_skip - 1);
1967 3820 : reverse = (indoption[attno_skip - 1] & INDOPTION_DESC) != 0;
1968 3820 : so->arrayKeys[numArrayKeys].attlen = attr->attlen;
1969 3820 : so->arrayKeys[numArrayKeys].attbyval = attr->attbyval;
1970 3820 : so->arrayKeys[numArrayKeys].null_elem = true; /* for now */
1971 7640 : so->arrayKeys[numArrayKeys].sksup =
1972 3820 : PrepareSkipSupportFromOpclass(opfamily, opcintype, reverse);
1973 3820 : so->arrayKeys[numArrayKeys].low_compare = NULL; /* for now */
1974 3820 : so->arrayKeys[numArrayKeys].high_compare = NULL; /* for now */
1975 :
1976 : /*
1977 : * We'll need a 3-way ORDER proc. Set that up now.
1978 : */
1979 3820 : _bt_setup_array_cmp(scan, cur, opcintype,
1980 3820 : &so->orderProcs[numArrayKeyData], NULL);
1981 :
1982 3820 : numArrayKeys++;
1983 3820 : numArrayKeyData++; /* keep this scan key/array */
1984 :
1985 : /* set up next output scan key */
1986 3820 : cur = &arrayKeyData[numArrayKeyData];
1987 :
1988 : /* remember having output this skip array and scan key */
1989 3820 : numSkipArrayKeys--;
1990 3820 : attno_skip++;
1991 : }
1992 :
1993 : /*
1994 : * Provisionally copy scan key into arrayKeyData[] array we'll return
1995 : * to _bt_preprocess_keys caller
1996 : */
1997 73178 : *cur = *inkey;
1998 :
1999 73178 : if (!(cur->sk_flags & SK_SEARCHARRAY))
2000 : {
2001 5306 : numArrayKeyData++; /* keep this non-array scan key */
2002 5324 : continue;
2003 : }
2004 :
2005 : /*
2006 : * Process SAOP array scan key
2007 : */
2008 : Assert(!(cur->sk_flags & (SK_ROW_HEADER | SK_SEARCHNULL | SK_SEARCHNOTNULL)));
2009 :
2010 : /* If array is null as a whole, the scan qual is unsatisfiable */
2011 67872 : if (cur->sk_flags & SK_ISNULL)
2012 : {
2013 6 : so->qual_ok = false;
2014 18 : break;
2015 : }
2016 :
2017 : /*
2018 : * Deconstruct the array into elements
2019 : */
2020 67866 : arrayval = DatumGetArrayTypeP(cur->sk_argument);
2021 : /* We could cache this data, but not clear it's worth it */
2022 67866 : get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
2023 : &elmlen, &elmbyval, &elmalign);
2024 67866 : deconstruct_array(arrayval,
2025 : ARR_ELEMTYPE(arrayval),
2026 : elmlen, elmbyval, elmalign,
2027 : &elem_values, &elem_nulls, &num_elems);
2028 :
2029 : /*
2030 : * Compress out any null elements. We can ignore them since we assume
2031 : * all btree operators are strict.
2032 : */
2033 67866 : num_nonnulls = 0;
2034 268910 : for (int j = 0; j < num_elems; j++)
2035 : {
2036 201044 : if (!elem_nulls[j])
2037 201026 : elem_values[num_nonnulls++] = elem_values[j];
2038 : }
2039 :
2040 : /* We could pfree(elem_nulls) now, but not worth the cycles */
2041 :
2042 : /* If there's no non-nulls, the scan qual is unsatisfiable */
2043 67866 : if (num_nonnulls == 0)
2044 : {
2045 6 : so->qual_ok = false;
2046 6 : break;
2047 : }
2048 :
2049 : /*
2050 : * Determine the nominal datatype of the array elements. We have to
2051 : * support the convention that sk_subtype == InvalidOid means the
2052 : * opclass input type; this is a hack to simplify life for
2053 : * ScanKeyInit().
2054 : */
2055 67860 : elemtype = cur->sk_subtype;
2056 67860 : if (elemtype == InvalidOid)
2057 0 : elemtype = rel->rd_opcintype[cur->sk_attno - 1];
2058 :
2059 : /*
2060 : * If the comparison operator is not equality, then the array qual
2061 : * degenerates to a simple comparison against the smallest or largest
2062 : * non-null array element, as appropriate.
2063 : */
2064 67860 : switch (cur->sk_strategy)
2065 : {
2066 6 : case BTLessStrategyNumber:
2067 : case BTLessEqualStrategyNumber:
2068 6 : cur->sk_argument =
2069 6 : _bt_find_extreme_element(scan, cur, elemtype,
2070 : BTGreaterStrategyNumber,
2071 : elem_values, num_nonnulls);
2072 6 : numArrayKeyData++; /* keep this transformed scan key */
2073 6 : continue;
2074 67848 : case BTEqualStrategyNumber:
2075 : /* proceed with rest of loop */
2076 67848 : break;
2077 6 : case BTGreaterEqualStrategyNumber:
2078 : case BTGreaterStrategyNumber:
2079 6 : cur->sk_argument =
2080 6 : _bt_find_extreme_element(scan, cur, elemtype,
2081 : BTLessStrategyNumber,
2082 : elem_values, num_nonnulls);
2083 6 : numArrayKeyData++; /* keep this transformed scan key */
2084 6 : continue;
2085 0 : default:
2086 0 : elog(ERROR, "unrecognized StrategyNumber: %d",
2087 : (int) cur->sk_strategy);
2088 : break;
2089 : }
2090 :
2091 : /*
2092 : * We'll need a 3-way ORDER proc to perform binary searches for the
2093 : * next matching array element. Set that up now.
2094 : *
2095 : * Array scan keys with cross-type equality operators will require a
2096 : * separate same-type ORDER proc for sorting their array. Otherwise,
2097 : * sortproc just points to the same proc used during binary searches.
2098 : */
2099 67848 : _bt_setup_array_cmp(scan, cur, elemtype,
2100 67848 : &so->orderProcs[numArrayKeyData], &sortprocp);
2101 :
2102 : /*
2103 : * Sort the non-null elements and eliminate any duplicates. We must
2104 : * sort in the same ordering used by the index column, so that the
2105 : * arrays can be advanced in lockstep with the scan's progress through
2106 : * the index's key space.
2107 : */
2108 67848 : reverse = (indoption[cur->sk_attno - 1] & INDOPTION_DESC) != 0;
2109 67848 : num_elems = _bt_sort_array_elements(cur, sortprocp, reverse,
2110 : elem_values, num_nonnulls);
2111 :
2112 67848 : if (origarrayatt == cur->sk_attno)
2113 : {
2114 12 : BTArrayKeyInfo *orig = &so->arrayKeys[origarraykey];
2115 :
2116 : /*
2117 : * This array scan key is redundant with a previous equality
2118 : * operator array scan key. Merge the two arrays together to
2119 : * eliminate contradictory non-intersecting elements (or try to).
2120 : *
2121 : * We merge this next array back into attribute's original array.
2122 : */
2123 : Assert(arrayKeyData[orig->scan_key].sk_attno == cur->sk_attno);
2124 : Assert(arrayKeyData[orig->scan_key].sk_collation ==
2125 : cur->sk_collation);
2126 12 : if (_bt_merge_arrays(scan, cur, sortprocp, reverse,
2127 : origelemtype, elemtype,
2128 : orig->elem_values, &orig->num_elems,
2129 : elem_values, num_elems))
2130 : {
2131 : /* Successfully eliminated this array */
2132 12 : pfree(elem_values);
2133 :
2134 : /*
2135 : * If no intersecting elements remain in the original array,
2136 : * the scan qual is unsatisfiable
2137 : */
2138 12 : if (orig->num_elems == 0)
2139 : {
2140 6 : so->qual_ok = false;
2141 6 : break;
2142 : }
2143 :
2144 : /* Throw away this scan key/array */
2145 6 : continue;
2146 : }
2147 :
2148 : /*
2149 : * Unable to merge this array with previous array due to a lack of
2150 : * suitable cross-type opfamily support. Will need to keep both
2151 : * scan keys/arrays.
2152 : */
2153 : }
2154 : else
2155 : {
2156 : /*
2157 : * This array is the first for current index attribute.
2158 : *
2159 : * If it turns out to not be the last array (that is, if the next
2160 : * array is redundantly applied to this same index attribute),
2161 : * we'll then treat this array as the attribute's "original" array
2162 : * when merging.
2163 : */
2164 67836 : origarrayatt = cur->sk_attno;
2165 67836 : origarraykey = numArrayKeys;
2166 67836 : origelemtype = elemtype;
2167 : }
2168 :
2169 : /* Initialize generic BTArrayKeyInfo fields */
2170 67836 : so->arrayKeys[numArrayKeys].scan_key = numArrayKeyData;
2171 67836 : so->arrayKeys[numArrayKeys].num_elems = num_elems;
2172 :
2173 : /* Initialize SAOP array specific BTArrayKeyInfo fields */
2174 67836 : so->arrayKeys[numArrayKeys].elem_values = elem_values;
2175 67836 : so->arrayKeys[numArrayKeys].cur_elem = -1; /* i.e. invalid */
2176 :
2177 67836 : numArrayKeys++;
2178 67836 : numArrayKeyData++; /* keep this scan key/array */
2179 : }
2180 :
2181 : Assert(numSkipArrayKeys == 0 || !so->qual_ok);
2182 :
2183 : /* Set final number of equality-type array keys */
2184 71368 : so->numArrayKeys = numArrayKeys;
2185 : /* Set number of scan keys in arrayKeyData[] */
2186 71368 : *new_numberOfKeys = numArrayKeyData;
2187 :
2188 71368 : MemoryContextSwitchTo(oldContext);
2189 :
2190 71368 : return arrayKeyData;
2191 : }
2192 :
2193 : /*
2194 : * _bt_preprocess_array_keys_final() -- fix up array scan key references
2195 : *
2196 : * When _bt_preprocess_array_keys performed initial array preprocessing, it
2197 : * set each array's array->scan_key to its scankey's arrayKeyData[] offset.
2198 : * This function handles translation of the scan key references from the
2199 : * BTArrayKeyInfo info array, from input scan key references (to the keys in
2200 : * arrayKeyData[]), into output references (to the keys in so->keyData[]).
2201 : * Caller's keyDataMap[] array tells us how to perform this remapping.
2202 : *
2203 : * Also finalizes so->orderProcs[] for the scan. Arrays already have an ORDER
2204 : * proc, which might need to be repositioned to its so->keyData[]-wise offset
2205 : * (very much like the remapping that we apply to array->scan_key references).
2206 : * Non-array equality strategy scan keys (that survived preprocessing) don't
2207 : * yet have an so->orderProcs[] entry, so we set one for them here.
2208 : *
2209 : * Also converts single-element array scan keys into equivalent non-array
2210 : * equality scan keys, which decrements so->numArrayKeys. It's possible that
2211 : * this will leave this new btrescan without any arrays at all. This isn't
2212 : * necessary for correctness; it's just an optimization. Non-array equality
2213 : * scan keys are slightly faster than equivalent array scan keys at runtime.
2214 : */
2215 : static void
2216 4312 : _bt_preprocess_array_keys_final(IndexScanDesc scan, int *keyDataMap)
2217 : {
2218 4312 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
2219 4312 : Relation rel = scan->indexRelation;
2220 4312 : int arrayidx = 0;
2221 4312 : int last_equal_output_ikey PG_USED_FOR_ASSERTS_ONLY = -1;
2222 :
2223 : Assert(so->qual_ok);
2224 :
2225 : /*
2226 : * Nothing for us to do when _bt_preprocess_array_keys only had to deal
2227 : * with array inequalities
2228 : */
2229 4312 : if (so->numArrayKeys == 0)
2230 0 : return;
2231 :
2232 13824 : for (int output_ikey = 0; output_ikey < so->numberOfKeys; output_ikey++)
2233 : {
2234 9524 : ScanKey outkey = so->keyData + output_ikey;
2235 : int input_ikey;
2236 9524 : bool found PG_USED_FOR_ASSERTS_ONLY = false;
2237 :
2238 : Assert(outkey->sk_strategy != InvalidStrategy);
2239 :
2240 9524 : if (outkey->sk_strategy != BTEqualStrategyNumber)
2241 104 : continue;
2242 :
2243 9420 : input_ikey = keyDataMap[output_ikey];
2244 :
2245 : Assert(last_equal_output_ikey < output_ikey);
2246 : Assert(last_equal_output_ikey < input_ikey);
2247 9420 : last_equal_output_ikey = output_ikey;
2248 :
2249 : /*
2250 : * We're lazy about looking up ORDER procs for non-array keys, since
2251 : * not all input keys become output keys. Take care of it now.
2252 : */
2253 9420 : if (!(outkey->sk_flags & SK_SEARCHARRAY))
2254 4742 : {
2255 : Oid elemtype;
2256 :
2257 : /* No need for an ORDER proc given an IS NULL scan key */
2258 4796 : if (outkey->sk_flags & SK_SEARCHNULL)
2259 54 : continue;
2260 :
2261 : /*
2262 : * A non-required scan key doesn't need an ORDER proc, either
2263 : * (unless it's associated with an array, which this one isn't)
2264 : */
2265 4742 : if (!(outkey->sk_flags & SK_BT_REQFWD))
2266 0 : continue;
2267 :
2268 4742 : elemtype = outkey->sk_subtype;
2269 4742 : if (elemtype == InvalidOid)
2270 2558 : elemtype = rel->rd_opcintype[outkey->sk_attno - 1];
2271 :
2272 4742 : _bt_setup_array_cmp(scan, outkey, elemtype,
2273 4742 : &so->orderProcs[output_ikey], NULL);
2274 4742 : continue;
2275 : }
2276 :
2277 : /*
2278 : * Reorder existing array scan key so->orderProcs[] entries.
2279 : *
2280 : * Doing this in-place is safe because preprocessing is required to
2281 : * output all equality strategy scan keys in original input order
2282 : * (among each group of entries against the same index attribute).
2283 : * This is also the order that the arrays themselves appear in.
2284 : */
2285 4624 : so->orderProcs[output_ikey] = so->orderProcs[input_ikey];
2286 :
2287 : /* Fix-up array->scan_key references for arrays */
2288 4624 : for (; arrayidx < so->numArrayKeys; arrayidx++)
2289 : {
2290 4624 : BTArrayKeyInfo *array = &so->arrayKeys[arrayidx];
2291 :
2292 : /*
2293 : * All skip arrays must be marked required, and final column can
2294 : * never have a skip array
2295 : */
2296 : Assert(array->num_elems > 0 || array->num_elems == -1);
2297 : Assert(array->num_elems != -1 || outkey->sk_flags & SK_BT_REQFWD);
2298 : Assert(array->num_elems != -1 ||
2299 : outkey->sk_attno < IndexRelationGetNumberOfKeyAttributes(rel));
2300 :
2301 4624 : if (array->scan_key == input_ikey)
2302 : {
2303 : /* found it */
2304 4624 : array->scan_key = output_ikey;
2305 4624 : found = true;
2306 :
2307 : /*
2308 : * Transform array scan keys that have exactly 1 element
2309 : * remaining (following all prior preprocessing) into
2310 : * equivalent non-array scan keys.
2311 : */
2312 4624 : if (array->num_elems == 1)
2313 : {
2314 18 : outkey->sk_flags &= ~SK_SEARCHARRAY;
2315 18 : outkey->sk_argument = array->elem_values[0];
2316 18 : so->numArrayKeys--;
2317 :
2318 : /* If we're out of array keys, we can quit right away */
2319 18 : if (so->numArrayKeys == 0)
2320 12 : return;
2321 :
2322 : /* Shift other arrays forward */
2323 6 : memmove(array, array + 1,
2324 : sizeof(BTArrayKeyInfo) *
2325 6 : (so->numArrayKeys - arrayidx));
2326 :
2327 : /*
2328 : * Don't increment arrayidx (there was an entry that was
2329 : * just shifted forward to the offset at arrayidx, which
2330 : * will still need to be matched)
2331 : */
2332 : }
2333 : else
2334 : {
2335 : /*
2336 : * Any skip array low_compare and high_compare scan keys
2337 : * are now final. Transform the array's > low_compare key
2338 : * into a >= key (and < high_compare keys into a <= key).
2339 : */
2340 4606 : if (array->num_elems == -1 && array->sksup &&
2341 3280 : !array->null_elem)
2342 78 : _bt_skiparray_strat_adjust(scan, outkey, array);
2343 :
2344 : /* Match found, so done with this array */
2345 4606 : arrayidx++;
2346 : }
2347 :
2348 4612 : break;
2349 : }
2350 : }
2351 :
2352 : Assert(found);
2353 : }
2354 :
2355 : /*
2356 : * Parallel index scans require space in shared memory to store the
2357 : * current array elements (for arrays kept by preprocessing) to schedule
2358 : * the next primitive index scan. The underlying structure is protected
2359 : * using an LWLock, so defensively limit its size. In practice this can
2360 : * only affect parallel scans that use an incomplete opfamily.
2361 : */
2362 4300 : if (scan->parallel_scan && so->numArrayKeys > INDEX_MAX_KEYS)
2363 0 : ereport(ERROR,
2364 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
2365 : errmsg_internal("number of array scan keys left by preprocessing (%d) exceeds the maximum allowed by parallel btree index scans (%d)",
2366 : so->numArrayKeys, INDEX_MAX_KEYS)));
2367 : }
2368 :
2369 : /*
2370 : * _bt_num_array_keys() -- determine # of BTArrayKeyInfo entries
2371 : *
2372 : * _bt_preprocess_array_keys helper function. Returns the estimated size of
2373 : * the scan's BTArrayKeyInfo array, which is guaranteed to be large enough to
2374 : * fit every so->arrayKeys[] entry.
2375 : *
2376 : * Also sets *numSkipArrayKeys_out to the number of skip arrays caller must
2377 : * add to the scan keys it'll output. Caller must add this many skip arrays:
2378 : * one array for each of the most significant attributes that lack a = input
2379 : * key (IS NULL keys count as = input keys here). The specific attributes
2380 : * that need skip arrays are indicated by initializing skip_eq_ops_out[] arg
2381 : * 0-based attribute offset to a valid = op strategy Oid. We'll only ever set
2382 : * skip_eq_ops_out[] entries to InvalidOid for attributes that already have an
2383 : * equality key in scan->keyData[] input keys -- and only when there's some
2384 : * later "attribute gap" for us to "fill-in" with a skip array.
2385 : *
2386 : * We're optimistic about skipping working out: we always add exactly the skip
2387 : * arrays needed to maximize the number of input scan keys that can ultimately
2388 : * be marked as required to continue the scan (but no more). Given a
2389 : * multi-column index on (a, b, c, d), we add skip arrays as follows:
2390 : *
2391 : * Input keys Output keys (after all preprocessing)
2392 : * ---------- -------------------------------------
2393 : * a = 1 a = 1 (no skip arrays)
2394 : * b = 42 skip a AND b = 42
2395 : * a = 1 AND b = 42 a = 1 AND b = 42 (no skip arrays)
2396 : * a >= 1 AND b = 42 range skip a AND b = 42
2397 : * a = 1 AND b > 42 a = 1 AND b > 42 (no skip arrays)
2398 : * a >= 1 AND a <= 3 AND b = 42 range skip a AND b = 42
2399 : * a = 1 AND c <= 27 a = 1 AND skip b AND c <= 27
2400 : * a = 1 AND d >= 1 a = 1 AND skip b AND skip c AND d >= 1
2401 : * a = 1 AND b >= 42 AND d > 1 a = 1 AND range skip b AND skip c AND d > 1
2402 : */
2403 : static int
2404 16396512 : _bt_num_array_keys(IndexScanDesc scan, Oid *skip_eq_ops_out,
2405 : int *numSkipArrayKeys_out)
2406 : {
2407 16396512 : Relation rel = scan->indexRelation;
2408 16396512 : AttrNumber attno_skip = 1,
2409 16396512 : attno_inkey = 1;
2410 16396512 : bool attno_has_equal = false,
2411 16396512 : attno_has_rowcompare = false;
2412 : int numSAOPArrayKeys,
2413 : numSkipArrayKeys,
2414 : prev_numSkipArrayKeys;
2415 :
2416 : Assert(scan->numberOfKeys);
2417 :
2418 : /* Initial pass over input scan keys counts the number of SAOP arrays */
2419 16396512 : numSAOPArrayKeys = 0;
2420 16396512 : *numSkipArrayKeys_out = prev_numSkipArrayKeys = numSkipArrayKeys = 0;
2421 42202722 : for (int i = 0; i < scan->numberOfKeys; i++)
2422 : {
2423 25806210 : ScanKey inkey = scan->keyData + i;
2424 :
2425 25806210 : if (inkey->sk_flags & SK_SEARCHARRAY)
2426 67872 : numSAOPArrayKeys++;
2427 : }
2428 :
2429 : #ifdef DEBUG_DISABLE_SKIP_SCAN
2430 : /* don't attempt to add skip arrays */
2431 : return numSAOPArrayKeys;
2432 : #endif
2433 :
2434 16396512 : for (int i = 0;; i++)
2435 25806180 : {
2436 42202692 : ScanKey inkey = scan->keyData + i;
2437 :
2438 : /*
2439 : * Backfill skip arrays for any wholly omitted attributes prior to
2440 : * attno_inkey
2441 : */
2442 42203256 : while (attno_skip < attno_inkey)
2443 : {
2444 564 : Oid opfamily = rel->rd_opfamily[attno_skip - 1];
2445 564 : Oid opcintype = rel->rd_opcintype[attno_skip - 1];
2446 :
2447 : /* Look up input opclass's equality operator (might fail) */
2448 1128 : skip_eq_ops_out[attno_skip - 1] =
2449 564 : get_opfamily_member(opfamily, opcintype, opcintype,
2450 : BTEqualStrategyNumber);
2451 564 : if (!OidIsValid(skip_eq_ops_out[attno_skip - 1]))
2452 : {
2453 : /*
2454 : * Cannot generate a skip array for this or later attributes
2455 : * (input opclass lacks an equality strategy operator)
2456 : */
2457 0 : *numSkipArrayKeys_out = prev_numSkipArrayKeys;
2458 0 : return numSAOPArrayKeys + prev_numSkipArrayKeys;
2459 : }
2460 :
2461 : /* plan on adding a backfill skip array for this attribute */
2462 564 : numSkipArrayKeys++;
2463 564 : attno_skip++;
2464 : }
2465 :
2466 42202692 : prev_numSkipArrayKeys = numSkipArrayKeys;
2467 :
2468 : /*
2469 : * Stop once past the final input scan key. We deliberately never add
2470 : * a skip array for the last input scan key's attribute -- even when
2471 : * there are only inequality keys on that attribute.
2472 : */
2473 42202692 : if (i == scan->numberOfKeys)
2474 16396494 : break;
2475 :
2476 : /*
2477 : * Later preprocessing steps cannot merge a RowCompare into a skip
2478 : * array, so stop adding skip arrays once we see one. (Note that we
2479 : * can backfill skip arrays before a RowCompare, which will allow keys
2480 : * up to and including the RowCompare to be marked required.)
2481 : *
2482 : * Skip arrays work by maintaining a current array element value,
2483 : * which anchors lower-order keys via an implied equality constraint.
2484 : * This is incompatible with the current nbtree row comparison design,
2485 : * which compares all columns together, as an indivisible group.
2486 : * Alternative designs that can be used alongside skip arrays are
2487 : * possible, but it's not clear that they're really worth pursuing.
2488 : *
2489 : * A RowCompare qual "(a, b, c) > (10, 'foo', 42)" is equivalent to
2490 : * "(a=10 AND b='foo' AND c>42) OR (a=10 AND b>'foo') OR (a>10)".
2491 : * Decomposing this RowCompare into these 3 disjuncts allows each
2492 : * disjunct to be executed as a separate "single value" index scan.
2493 : * That'll give all 3 scans the ability to add skip arrays in the
2494 : * usual way (when there are any scalar keys after the RowCompare).
2495 : * Under this scheme, a qual "(a, b, c) > (10, 'foo', 42) AND d = 99"
2496 : * performs 3 separate scans, each of which can mark keys up to and
2497 : * including its "d = 99" key as required to continue the scan.
2498 : */
2499 25806198 : if (attno_has_rowcompare)
2500 18 : break;
2501 :
2502 : /*
2503 : * Now consider next attno_inkey (or keep going if this is an
2504 : * additional scan key against the same attribute)
2505 : */
2506 25806180 : if (attno_inkey < inkey->sk_attno)
2507 : {
2508 : /*
2509 : * Now add skip array for previous scan key's attribute, though
2510 : * only if the attribute has no equality strategy scan keys
2511 : */
2512 9410456 : if (attno_has_equal)
2513 : {
2514 : /* Attributes with an = key must have InvalidOid eq_op set */
2515 9407200 : skip_eq_ops_out[attno_skip - 1] = InvalidOid;
2516 : }
2517 : else
2518 : {
2519 3256 : Oid opfamily = rel->rd_opfamily[attno_skip - 1];
2520 3256 : Oid opcintype = rel->rd_opcintype[attno_skip - 1];
2521 :
2522 : /* Look up input opclass's equality operator (might fail) */
2523 6512 : skip_eq_ops_out[attno_skip - 1] =
2524 3256 : get_opfamily_member(opfamily, opcintype, opcintype,
2525 : BTEqualStrategyNumber);
2526 :
2527 3256 : if (!OidIsValid(skip_eq_ops_out[attno_skip - 1]))
2528 : {
2529 : /*
2530 : * Input opclass lacks an equality strategy operator, so
2531 : * don't generate a skip array that definitely won't work
2532 : */
2533 0 : break;
2534 : }
2535 :
2536 : /* plan on adding a backfill skip array for this attribute */
2537 3256 : numSkipArrayKeys++;
2538 : }
2539 :
2540 : /* Set things up for this new attribute */
2541 9410456 : attno_skip++;
2542 9410456 : attno_inkey = inkey->sk_attno;
2543 9410456 : attno_has_equal = false;
2544 : }
2545 :
2546 : /*
2547 : * Track if this attribute's scan keys include any equality strategy
2548 : * scan keys (IS NULL keys count as equality keys here). Also track
2549 : * if it has any RowCompare keys.
2550 : */
2551 25806180 : if (inkey->sk_strategy == BTEqualStrategyNumber ||
2552 1828206 : (inkey->sk_flags & SK_SEARCHNULL))
2553 23978118 : attno_has_equal = true;
2554 25806180 : if (inkey->sk_flags & SK_ROW_HEADER)
2555 84 : attno_has_rowcompare = true;
2556 : }
2557 :
2558 16396512 : *numSkipArrayKeys_out = numSkipArrayKeys;
2559 16396512 : return numSAOPArrayKeys + numSkipArrayKeys;
2560 : }
2561 :
2562 : /*
2563 : * _bt_find_extreme_element() -- get least or greatest array element
2564 : *
2565 : * scan and skey identify the index column, whose opfamily determines the
2566 : * comparison semantics. strat should be BTLessStrategyNumber to get the
2567 : * least element, or BTGreaterStrategyNumber to get the greatest.
2568 : */
2569 : static Datum
2570 12 : _bt_find_extreme_element(IndexScanDesc scan, ScanKey skey, Oid elemtype,
2571 : StrategyNumber strat,
2572 : Datum *elems, int nelems)
2573 : {
2574 12 : Relation rel = scan->indexRelation;
2575 : Oid cmp_op;
2576 : RegProcedure cmp_proc;
2577 : FmgrInfo flinfo;
2578 : Datum result;
2579 : int i;
2580 :
2581 : /*
2582 : * Look up the appropriate comparison operator in the opfamily.
2583 : *
2584 : * Note: it's possible that this would fail, if the opfamily is
2585 : * incomplete, but it seems quite unlikely that an opfamily would omit
2586 : * non-cross-type comparison operators for any datatype that it supports
2587 : * at all.
2588 : */
2589 : Assert(skey->sk_strategy != BTEqualStrategyNumber);
2590 : Assert(OidIsValid(elemtype));
2591 12 : cmp_op = get_opfamily_member(rel->rd_opfamily[skey->sk_attno - 1],
2592 : elemtype,
2593 : elemtype,
2594 : strat);
2595 12 : if (!OidIsValid(cmp_op))
2596 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
2597 : strat, elemtype, elemtype,
2598 : rel->rd_opfamily[skey->sk_attno - 1]);
2599 12 : cmp_proc = get_opcode(cmp_op);
2600 12 : if (!RegProcedureIsValid(cmp_proc))
2601 0 : elog(ERROR, "missing oprcode for operator %u", cmp_op);
2602 :
2603 12 : fmgr_info(cmp_proc, &flinfo);
2604 :
2605 : Assert(nelems > 0);
2606 12 : result = elems[0];
2607 36 : for (i = 1; i < nelems; i++)
2608 : {
2609 24 : if (DatumGetBool(FunctionCall2Coll(&flinfo,
2610 : skey->sk_collation,
2611 24 : elems[i],
2612 : result)))
2613 6 : result = elems[i];
2614 : }
2615 :
2616 12 : return result;
2617 : }
2618 :
2619 : /*
2620 : * _bt_setup_array_cmp() -- Set up array comparison functions
2621 : *
2622 : * Sets ORDER proc in caller's orderproc argument, which is used during binary
2623 : * searches of arrays during the index scan. Also sets a same-type ORDER proc
2624 : * in caller's *sortprocp argument, which is used when sorting the array.
2625 : *
2626 : * Preprocessing calls here with all equality strategy scan keys (when scan
2627 : * uses equality array keys), including those not associated with any array.
2628 : * See _bt_advance_array_keys for an explanation of why it'll need to treat
2629 : * simple scalar equality scan keys as degenerate single element arrays.
2630 : *
2631 : * Caller should pass an orderproc pointing to space that'll store the ORDER
2632 : * proc for the scan, and a *sortprocp pointing to its own separate space.
2633 : * When calling here for a non-array scan key, sortprocp arg should be NULL.
2634 : *
2635 : * In the common case where we don't need to deal with cross-type operators,
2636 : * only one ORDER proc is actually required by caller. We'll set *sortprocp
2637 : * to point to the same memory that caller's orderproc continues to point to.
2638 : * Otherwise, *sortprocp will continue to point to caller's own space. Either
2639 : * way, *sortprocp will point to a same-type ORDER proc (since that's the only
2640 : * safe way to sort/deduplicate the array associated with caller's scan key).
2641 : */
2642 : static void
2643 76410 : _bt_setup_array_cmp(IndexScanDesc scan, ScanKey skey, Oid elemtype,
2644 : FmgrInfo *orderproc, FmgrInfo **sortprocp)
2645 : {
2646 76410 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
2647 76410 : Relation rel = scan->indexRelation;
2648 : RegProcedure cmp_proc;
2649 76410 : Oid opcintype = rel->rd_opcintype[skey->sk_attno - 1];
2650 :
2651 : Assert(skey->sk_strategy == BTEqualStrategyNumber);
2652 : Assert(OidIsValid(elemtype));
2653 :
2654 : /*
2655 : * If scankey operator is not a cross-type comparison, we can use the
2656 : * cached comparison function; otherwise gotta look it up in the catalogs
2657 : */
2658 76410 : if (elemtype == opcintype)
2659 : {
2660 : /* Set same-type ORDER procs for caller */
2661 76140 : *orderproc = *index_getprocinfo(rel, skey->sk_attno, BTORDER_PROC);
2662 76140 : if (sortprocp)
2663 67842 : *sortprocp = orderproc;
2664 :
2665 76140 : return;
2666 : }
2667 :
2668 : /*
2669 : * Look up the appropriate cross-type comparison function in the opfamily.
2670 : *
2671 : * Use the opclass input type as the left hand arg type, and the array
2672 : * element type as the right hand arg type (since binary searches use an
2673 : * index tuple's attribute value to search for a matching array element).
2674 : *
2675 : * Note: it's possible that this would fail, if the opfamily is
2676 : * incomplete, but only in cases where it's quite likely that _bt_first
2677 : * would fail in just the same way (had we not failed before it could).
2678 : */
2679 270 : cmp_proc = get_opfamily_proc(rel->rd_opfamily[skey->sk_attno - 1],
2680 : opcintype, elemtype, BTORDER_PROC);
2681 270 : if (!RegProcedureIsValid(cmp_proc))
2682 0 : elog(ERROR, "missing support function %d(%u,%u) for attribute %d of index \"%s\"",
2683 : BTORDER_PROC, opcintype, elemtype, skey->sk_attno,
2684 : RelationGetRelationName(rel));
2685 :
2686 : /* Set cross-type ORDER proc for caller */
2687 270 : fmgr_info_cxt(cmp_proc, orderproc, so->arrayContext);
2688 :
2689 : /* Done if caller doesn't actually have an array they'll need to sort */
2690 270 : if (!sortprocp)
2691 264 : return;
2692 :
2693 : /*
2694 : * Look up the appropriate same-type comparison function in the opfamily.
2695 : *
2696 : * Note: it's possible that this would fail, if the opfamily is
2697 : * incomplete, but it seems quite unlikely that an opfamily would omit
2698 : * non-cross-type comparison procs for any datatype that it supports at
2699 : * all.
2700 : */
2701 6 : cmp_proc = get_opfamily_proc(rel->rd_opfamily[skey->sk_attno - 1],
2702 : elemtype, elemtype, BTORDER_PROC);
2703 6 : if (!RegProcedureIsValid(cmp_proc))
2704 0 : elog(ERROR, "missing support function %d(%u,%u) for attribute %d of index \"%s\"",
2705 : BTORDER_PROC, elemtype, elemtype,
2706 : skey->sk_attno, RelationGetRelationName(rel));
2707 :
2708 : /* Set same-type ORDER proc for caller */
2709 6 : fmgr_info_cxt(cmp_proc, *sortprocp, so->arrayContext);
2710 : }
2711 :
2712 : /*
2713 : * _bt_sort_array_elements() -- sort and de-dup array elements
2714 : *
2715 : * The array elements are sorted in-place, and the new number of elements
2716 : * after duplicate removal is returned.
2717 : *
2718 : * skey identifies the index column whose opfamily determines the comparison
2719 : * semantics, and sortproc is a corresponding ORDER proc. If reverse is true,
2720 : * we sort in descending order.
2721 : */
2722 : static int
2723 67848 : _bt_sort_array_elements(ScanKey skey, FmgrInfo *sortproc, bool reverse,
2724 : Datum *elems, int nelems)
2725 : {
2726 : BTSortArrayContext cxt;
2727 :
2728 67848 : if (nelems <= 1)
2729 52 : return nelems; /* no work to do */
2730 :
2731 : /* Sort the array elements */
2732 67796 : cxt.sortproc = sortproc;
2733 67796 : cxt.collation = skey->sk_collation;
2734 67796 : cxt.reverse = reverse;
2735 67796 : qsort_arg(elems, nelems, sizeof(Datum),
2736 : _bt_compare_array_elements, &cxt);
2737 :
2738 : /* Now scan the sorted elements and remove duplicates */
2739 67796 : return qunique_arg(elems, nelems, sizeof(Datum),
2740 : _bt_compare_array_elements, &cxt);
2741 : }
2742 :
2743 : /*
2744 : * _bt_merge_arrays() -- merge next array's elements into an original array
2745 : *
2746 : * Called when preprocessing encounters a pair of array equality scan keys,
2747 : * both against the same index attribute (during initial array preprocessing).
2748 : * Merging reorganizes caller's original array (the left hand arg) in-place,
2749 : * without ever copying elements from one array into the other. (Mixing the
2750 : * elements together like this would be wrong, since they don't necessarily
2751 : * use the same underlying element type, despite all the other similarities.)
2752 : *
2753 : * Both arrays must have already been sorted and deduplicated by calling
2754 : * _bt_sort_array_elements. sortproc is the same-type ORDER proc that was
2755 : * just used to sort and deduplicate caller's "next" array. We'll usually be
2756 : * able to reuse that order PROC to merge the arrays together now. If not,
2757 : * then we'll perform a separate ORDER proc lookup.
2758 : *
2759 : * If the opfamily doesn't supply a complete set of cross-type ORDER procs we
2760 : * may not be able to determine which elements are contradictory. If we have
2761 : * the required ORDER proc then we return true (and validly set *nelems_orig),
2762 : * guaranteeing that at least the next array can be considered redundant. We
2763 : * return false if the required comparisons cannot be made (caller must keep
2764 : * both arrays when this happens).
2765 : */
2766 : static bool
2767 12 : _bt_merge_arrays(IndexScanDesc scan, ScanKey skey, FmgrInfo *sortproc,
2768 : bool reverse, Oid origelemtype, Oid nextelemtype,
2769 : Datum *elems_orig, int *nelems_orig,
2770 : Datum *elems_next, int nelems_next)
2771 : {
2772 12 : Relation rel = scan->indexRelation;
2773 12 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
2774 : BTSortArrayContext cxt;
2775 12 : int nelems_orig_start = *nelems_orig,
2776 12 : nelems_orig_merged = 0;
2777 12 : FmgrInfo *mergeproc = sortproc;
2778 : FmgrInfo crosstypeproc;
2779 :
2780 : Assert(skey->sk_strategy == BTEqualStrategyNumber);
2781 : Assert(OidIsValid(origelemtype) && OidIsValid(nextelemtype));
2782 :
2783 12 : if (origelemtype != nextelemtype)
2784 : {
2785 : RegProcedure cmp_proc;
2786 :
2787 : /*
2788 : * Cross-array-element-type merging is required, so can't just reuse
2789 : * sortproc when merging
2790 : */
2791 6 : cmp_proc = get_opfamily_proc(rel->rd_opfamily[skey->sk_attno - 1],
2792 : origelemtype, nextelemtype, BTORDER_PROC);
2793 6 : if (!RegProcedureIsValid(cmp_proc))
2794 : {
2795 : /* Can't make the required comparisons */
2796 0 : return false;
2797 : }
2798 :
2799 : /* We have all we need to determine redundancy/contradictoriness */
2800 6 : mergeproc = &crosstypeproc;
2801 6 : fmgr_info_cxt(cmp_proc, mergeproc, so->arrayContext);
2802 : }
2803 :
2804 12 : cxt.sortproc = mergeproc;
2805 12 : cxt.collation = skey->sk_collation;
2806 12 : cxt.reverse = reverse;
2807 :
2808 54 : for (int i = 0, j = 0; i < nelems_orig_start && j < nelems_next;)
2809 : {
2810 42 : Datum *oelem = elems_orig + i,
2811 42 : *nelem = elems_next + j;
2812 42 : int res = _bt_compare_array_elements(oelem, nelem, &cxt);
2813 :
2814 42 : if (res == 0)
2815 : {
2816 6 : elems_orig[nelems_orig_merged++] = *oelem;
2817 6 : i++;
2818 6 : j++;
2819 : }
2820 36 : else if (res < 0)
2821 24 : i++;
2822 : else /* res > 0 */
2823 12 : j++;
2824 : }
2825 :
2826 12 : *nelems_orig = nelems_orig_merged;
2827 :
2828 12 : return true;
2829 : }
2830 :
2831 : /*
2832 : * qsort_arg comparator for sorting array elements
2833 : */
2834 : static int
2835 302920 : _bt_compare_array_elements(const void *a, const void *b, void *arg)
2836 : {
2837 302920 : Datum da = *((const Datum *) a);
2838 302920 : Datum db = *((const Datum *) b);
2839 302920 : BTSortArrayContext *cxt = (BTSortArrayContext *) arg;
2840 : int32 compare;
2841 :
2842 302920 : compare = DatumGetInt32(FunctionCall2Coll(cxt->sortproc,
2843 : cxt->collation,
2844 : da, db));
2845 302920 : if (cxt->reverse)
2846 30 : INVERT_COMPARE_RESULT(compare);
2847 302920 : return compare;
2848 : }
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