Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * pgpa_ast.c
4 : * additional supporting code related to plan advice parsing
5 : *
6 : * Copyright (c) 2016-2026, PostgreSQL Global Development Group
7 : *
8 : * contrib/pg_plan_advice/pgpa_ast.c
9 : *
10 : *-------------------------------------------------------------------------
11 : */
12 :
13 : #include "postgres.h"
14 :
15 : #include "pgpa_ast.h"
16 :
17 : #include "funcapi.h"
18 : #include "utils/array.h"
19 : #include "utils/builtins.h"
20 :
21 : static bool pgpa_identifiers_cover_target(int nrids, pgpa_identifier *rids,
22 : pgpa_advice_target *target,
23 : bool *rids_used);
24 :
25 : /*
26 : * Get a C string that corresponds to the specified advice tag.
27 : */
28 : char *
29 142506 : pgpa_cstring_advice_tag(pgpa_advice_tag_type advice_tag)
30 : {
31 142506 : switch (advice_tag)
32 : {
33 2437 : case PGPA_TAG_BITMAP_HEAP_SCAN:
34 2437 : return "BITMAP_HEAP_SCAN";
35 328 : case PGPA_TAG_DO_NOT_SCAN:
36 328 : return "DO_NOT_SCAN";
37 1 : case PGPA_TAG_FOREIGN_JOIN:
38 1 : return "FOREIGN_JOIN";
39 172 : case PGPA_TAG_GATHER:
40 172 : return "GATHER";
41 61 : case PGPA_TAG_GATHER_MERGE:
42 61 : return "GATHER_MERGE";
43 4718 : case PGPA_TAG_HASH_JOIN:
44 4718 : return "HASH_JOIN";
45 1927 : case PGPA_TAG_INDEX_ONLY_SCAN:
46 1927 : return "INDEX_ONLY_SCAN";
47 11550 : case PGPA_TAG_INDEX_SCAN:
48 11550 : return "INDEX_SCAN";
49 10910 : case PGPA_TAG_JOIN_ORDER:
50 10910 : return "JOIN_ORDER";
51 27 : case PGPA_TAG_MERGE_JOIN_MATERIALIZE:
52 27 : return "MERGE_JOIN_MATERIALIZE";
53 557 : case PGPA_TAG_MERGE_JOIN_PLAIN:
54 557 : return "MERGE_JOIN_PLAIN";
55 500 : case PGPA_TAG_NESTED_LOOP_MATERIALIZE:
56 500 : return "NESTED_LOOP_MATERIALIZE";
57 229 : case PGPA_TAG_NESTED_LOOP_MEMOIZE:
58 229 : return "NESTED_LOOP_MEMOIZE";
59 8431 : case PGPA_TAG_NESTED_LOOP_PLAIN:
60 8431 : return "NESTED_LOOP_PLAIN";
61 70708 : case PGPA_TAG_NO_GATHER:
62 70708 : return "NO_GATHER";
63 2192 : case PGPA_TAG_PARTITIONWISE:
64 2192 : return "PARTITIONWISE";
65 625 : case PGPA_TAG_SEMIJOIN_NON_UNIQUE:
66 625 : return "SEMIJOIN_NON_UNIQUE";
67 79 : case PGPA_TAG_SEMIJOIN_UNIQUE:
68 79 : return "SEMIJOIN_UNIQUE";
69 26632 : case PGPA_TAG_SEQ_SCAN:
70 26632 : return "SEQ_SCAN";
71 422 : case PGPA_TAG_TID_SCAN:
72 422 : return "TID_SCAN";
73 : }
74 :
75 0 : pg_unreachable();
76 : return NULL;
77 : }
78 :
79 : /*
80 : * Convert an advice tag, formatted as a string that has already been
81 : * downcased as appropriate, to a pgpa_advice_tag_type.
82 : *
83 : * If we succeed, set *fail = false and return the result; if we fail,
84 : * set *fail = true and return an arbitrary value.
85 : */
86 : pgpa_advice_tag_type
87 336331 : pgpa_parse_advice_tag(const char *tag, bool *fail)
88 : {
89 336331 : *fail = false;
90 :
91 336331 : switch (tag[0])
92 : {
93 8997 : case 'b':
94 8997 : if (strcmp(tag, "bitmap_heap_scan") == 0)
95 2333 : return PGPA_TAG_BITMAP_HEAP_SCAN;
96 6664 : break;
97 3047 : case 'd':
98 3047 : if (strcmp(tag, "do_not_scan") == 0)
99 181 : return PGPA_TAG_DO_NOT_SCAN;
100 2866 : break;
101 5435 : case 'f':
102 5435 : if (strcmp(tag, "foreign_join") == 0)
103 8 : return PGPA_TAG_FOREIGN_JOIN;
104 5427 : break;
105 2561 : case 'g':
106 2561 : if (strcmp(tag, "gather") == 0)
107 339 : return PGPA_TAG_GATHER;
108 2222 : if (strcmp(tag, "gather_merge") == 0)
109 118 : return PGPA_TAG_GATHER_MERGE;
110 2104 : break;
111 6394 : case 'h':
112 6394 : if (strcmp(tag, "hash_join") == 0)
113 5749 : return PGPA_TAG_HASH_JOIN;
114 645 : break;
115 16343 : case 'i':
116 16343 : if (strcmp(tag, "index_scan") == 0)
117 6999 : return PGPA_TAG_INDEX_SCAN;
118 9344 : if (strcmp(tag, "index_only_scan") == 0)
119 1715 : return PGPA_TAG_INDEX_ONLY_SCAN;
120 7629 : break;
121 11605 : case 'j':
122 11605 : if (strcmp(tag, "join_order") == 0)
123 10933 : return PGPA_TAG_JOIN_ORDER;
124 672 : break;
125 4296 : case 'm':
126 4296 : if (strcmp(tag, "merge_join_materialize") == 0)
127 58 : return PGPA_TAG_MERGE_JOIN_MATERIALIZE;
128 4238 : if (strcmp(tag, "merge_join_plain") == 0)
129 934 : return PGPA_TAG_MERGE_JOIN_PLAIN;
130 3304 : break;
131 62430 : case 'n':
132 62430 : if (strcmp(tag, "nested_loop_materialize") == 0)
133 910 : return PGPA_TAG_NESTED_LOOP_MATERIALIZE;
134 61520 : if (strcmp(tag, "nested_loop_memoize") == 0)
135 438 : return PGPA_TAG_NESTED_LOOP_MEMOIZE;
136 61082 : if (strcmp(tag, "nested_loop_plain") == 0)
137 11514 : return PGPA_TAG_NESTED_LOOP_PLAIN;
138 49568 : if (strcmp(tag, "no_gather") == 0)
139 43414 : return PGPA_TAG_NO_GATHER;
140 6154 : break;
141 82724 : case 'p':
142 82724 : if (strcmp(tag, "partitionwise") == 0)
143 3368 : return PGPA_TAG_PARTITIONWISE;
144 79356 : break;
145 39561 : case 's':
146 39561 : if (strcmp(tag, "semijoin_non_unique") == 0)
147 1180 : return PGPA_TAG_SEMIJOIN_NON_UNIQUE;
148 38381 : if (strcmp(tag, "semijoin_unique") == 0)
149 150 : return PGPA_TAG_SEMIJOIN_UNIQUE;
150 38231 : if (strcmp(tag, "seq_scan") == 0)
151 16394 : return PGPA_TAG_SEQ_SCAN;
152 21837 : break;
153 23894 : case 't':
154 23894 : if (strcmp(tag, "tid_scan") == 0)
155 405 : return PGPA_TAG_TID_SCAN;
156 23489 : break;
157 : }
158 :
159 : /* didn't work out */
160 229191 : *fail = true;
161 :
162 : /* return an arbitrary value to unwind the call stack */
163 229191 : return PGPA_TAG_SEQ_SCAN;
164 : }
165 :
166 : /*
167 : * Format a pgpa_advice_target as a string and append result to a StringInfo.
168 : */
169 : void
170 170337 : pgpa_format_advice_target(StringInfo str, pgpa_advice_target *target)
171 : {
172 170337 : if (target->ttype != PGPA_TARGET_IDENTIFIER)
173 : {
174 12283 : bool first = true;
175 : char *delims;
176 :
177 12283 : if (target->ttype == PGPA_TARGET_UNORDERED_LIST)
178 14 : delims = "{}";
179 : else
180 12269 : delims = "()";
181 :
182 12283 : appendStringInfoChar(str, delims[0]);
183 52397 : foreach_ptr(pgpa_advice_target, child_target, target->children)
184 : {
185 27831 : if (first)
186 12283 : first = false;
187 : else
188 15548 : appendStringInfoChar(str, ' ');
189 27831 : pgpa_format_advice_target(str, child_target);
190 : }
191 12283 : appendStringInfoChar(str, delims[1]);
192 : }
193 : else
194 : {
195 : const char *rt_identifier;
196 :
197 158054 : rt_identifier = pgpa_identifier_string(&target->rid);
198 158054 : appendStringInfoString(str, rt_identifier);
199 : }
200 170337 : }
201 :
202 : /*
203 : * Format a pgpa_index_target as a string and append result to a StringInfo.
204 : */
205 : void
206 13477 : pgpa_format_index_target(StringInfo str, pgpa_index_target *itarget)
207 : {
208 13477 : if (itarget->indnamespace != NULL)
209 13459 : appendStringInfo(str, "%s.",
210 13459 : quote_identifier(itarget->indnamespace));
211 13477 : appendStringInfoString(str, quote_identifier(itarget->indname));
212 13477 : }
213 :
214 : /*
215 : * Determine whether two pgpa_index_target objects are exactly identical.
216 : */
217 : bool
218 2 : pgpa_index_targets_equal(pgpa_index_target *i1, pgpa_index_target *i2)
219 : {
220 : /* indnamespace can be NULL, and two NULL values are equal */
221 2 : if ((i1->indnamespace != NULL || i2->indnamespace != NULL) &&
222 1 : (i1->indnamespace == NULL || i2->indnamespace == NULL ||
223 0 : strcmp(i1->indnamespace, i2->indnamespace) != 0))
224 1 : return false;
225 1 : if (strcmp(i1->indname, i2->indname) != 0)
226 0 : return false;
227 :
228 1 : return true;
229 : }
230 :
231 : /*
232 : * Check whether an identifier matches an any part of an advice target.
233 : */
234 : bool
235 1481520 : pgpa_identifier_matches_target(pgpa_identifier *rid, pgpa_advice_target *target)
236 : {
237 : /* For non-identifiers, check all descendants. */
238 1481520 : if (target->ttype != PGPA_TARGET_IDENTIFIER)
239 : {
240 159339 : foreach_ptr(pgpa_advice_target, child_target, target->children)
241 : {
242 152149 : if (pgpa_identifier_matches_target(rid, child_target))
243 73673 : return true;
244 : }
245 3595 : return false;
246 : }
247 :
248 : /* Straightforward comparisons of alias name and occurrence number. */
249 1404252 : if (strcmp(rid->alias_name, target->rid.alias_name) != 0)
250 806778 : return false;
251 597474 : if (rid->occurrence != target->rid.occurrence)
252 27126 : return false;
253 :
254 : /*
255 : * If a relation identifier mentions a partition name, it should also
256 : * specify a partition schema. But the target may leave the schema NULL to
257 : * match anything.
258 : */
259 : Assert(rid->partnsp != NULL || rid->partrel == NULL);
260 570348 : if (rid->partnsp != NULL && target->rid.partnsp != NULL &&
261 48269 : strcmp(rid->partnsp, target->rid.partnsp) != 0)
262 0 : return false;
263 :
264 : /*
265 : * These fields can be NULL on either side, but NULL only matches another
266 : * NULL.
267 : */
268 570348 : if (!strings_equal_or_both_null(rid->partrel, target->rid.partrel))
269 11 : return false;
270 570337 : if (!strings_equal_or_both_null(rid->plan_name, target->rid.plan_name))
271 0 : return false;
272 :
273 570337 : return true;
274 : }
275 :
276 : /*
277 : * Match identifiers to advice targets and return an enum value indicating
278 : * the relationship between the set of keys and the set of targets.
279 : *
280 : * See the comments for pgpa_itm_type.
281 : */
282 : pgpa_itm_type
283 357297 : pgpa_identifiers_match_target(int nrids, pgpa_identifier *rids,
284 : pgpa_advice_target *target)
285 : {
286 357297 : bool all_rids_used = true;
287 357297 : bool any_rids_used = false;
288 : bool all_targets_used;
289 357297 : bool *rids_used = palloc0_array(bool, nrids);
290 :
291 : all_targets_used =
292 357297 : pgpa_identifiers_cover_target(nrids, rids, target, rids_used);
293 :
294 1008435 : for (int i = 0; i < nrids; ++i)
295 : {
296 651138 : if (rids_used[i])
297 302247 : any_rids_used = true;
298 : else
299 348891 : all_rids_used = false;
300 : }
301 :
302 357297 : if (all_rids_used)
303 : {
304 137694 : if (all_targets_used)
305 118818 : return PGPA_ITM_EQUAL;
306 : else
307 18876 : return PGPA_ITM_KEYS_ARE_SUBSET;
308 : }
309 : else
310 : {
311 219603 : if (all_targets_used)
312 84024 : return PGPA_ITM_TARGETS_ARE_SUBSET;
313 135579 : else if (any_rids_used)
314 20737 : return PGPA_ITM_INTERSECTING;
315 : else
316 114842 : return PGPA_ITM_DISJOINT;
317 : }
318 : }
319 :
320 : /*
321 : * Returns true if every target or sub-target is matched by at least one
322 : * identifier, and otherwise false.
323 : *
324 : * Also sets rids_used[i] = true for each identifier that matches at least one
325 : * target.
326 : */
327 : static bool
328 653842 : pgpa_identifiers_cover_target(int nrids, pgpa_identifier *rids,
329 : pgpa_advice_target *target, bool *rids_used)
330 : {
331 653842 : bool result = false;
332 :
333 653842 : if (target->ttype != PGPA_TARGET_IDENTIFIER)
334 : {
335 160550 : result = true;
336 :
337 617645 : foreach_ptr(pgpa_advice_target, child_target, target->children)
338 : {
339 296545 : if (!pgpa_identifiers_cover_target(nrids, rids, child_target,
340 : rids_used))
341 133869 : result = false;
342 : }
343 : }
344 : else
345 : {
346 1544933 : for (int i = 0; i < nrids; ++i)
347 : {
348 1051641 : if (pgpa_identifier_matches_target(&rids[i], target))
349 : {
350 302247 : rids_used[i] = true;
351 302247 : result = true;
352 : }
353 : }
354 : }
355 :
356 653842 : return result;
357 : }
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