Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * nbtree.h
4 : * header file for postgres btree access method implementation.
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : * src/include/access/nbtree.h
11 : *
12 : *-------------------------------------------------------------------------
13 : */
14 : #ifndef NBTREE_H
15 : #define NBTREE_H
16 :
17 : #include "access/amapi.h"
18 : #include "access/itup.h"
19 : #include "access/sdir.h"
20 : #include "catalog/pg_am_d.h"
21 : #include "catalog/pg_class.h"
22 : #include "catalog/pg_index.h"
23 : #include "lib/stringinfo.h"
24 : #include "storage/bufmgr.h"
25 : #include "storage/dsm.h"
26 : #include "storage/shm_toc.h"
27 : #include "utils/skipsupport.h"
28 :
29 : /* There's room for a 16-bit vacuum cycle ID in BTPageOpaqueData */
30 : typedef uint16 BTCycleId;
31 :
32 : /*
33 : * BTPageOpaqueData -- At the end of every page, we store a pointer
34 : * to both siblings in the tree. This is used to do forward/backward
35 : * index scans. The next-page link is also critical for recovery when
36 : * a search has navigated to the wrong page due to concurrent page splits
37 : * or deletions; see src/backend/access/nbtree/README for more info.
38 : *
39 : * In addition, we store the page's btree level (counting upwards from
40 : * zero at a leaf page) as well as some flag bits indicating the page type
41 : * and status. If the page is deleted, a BTDeletedPageData struct is stored
42 : * in the page's tuple area, while a standard BTPageOpaqueData struct is
43 : * stored in the page special area.
44 : *
45 : * We also store a "vacuum cycle ID". When a page is split while VACUUM is
46 : * processing the index, a nonzero value associated with the VACUUM run is
47 : * stored into both halves of the split page. (If VACUUM is not running,
48 : * both pages receive zero cycleids.) This allows VACUUM to detect whether
49 : * a page was split since it started, with a small probability of false match
50 : * if the page was last split some exact multiple of MAX_BT_CYCLE_ID VACUUMs
51 : * ago. Also, during a split, the BTP_SPLIT_END flag is cleared in the left
52 : * (original) page, and set in the right page, but only if the next page
53 : * to its right has a different cycleid.
54 : *
55 : * NOTE: the BTP_LEAF flag bit is redundant since level==0 could be tested
56 : * instead.
57 : *
58 : * NOTE: the btpo_level field used to be a union type in order to allow
59 : * deleted pages to store a 32-bit safexid in the same field. We now store
60 : * 64-bit/full safexid values using BTDeletedPageData instead.
61 : */
62 :
63 : typedef struct BTPageOpaqueData
64 : {
65 : BlockNumber btpo_prev; /* left sibling, or P_NONE if leftmost */
66 : BlockNumber btpo_next; /* right sibling, or P_NONE if rightmost */
67 : uint32 btpo_level; /* tree level --- zero for leaf pages */
68 : uint16 btpo_flags; /* flag bits, see below */
69 : BTCycleId btpo_cycleid; /* vacuum cycle ID of latest split */
70 : } BTPageOpaqueData;
71 :
72 : typedef BTPageOpaqueData *BTPageOpaque;
73 :
74 : #define BTPageGetOpaque(page) ((BTPageOpaque) PageGetSpecialPointer(page))
75 :
76 : /* Bits defined in btpo_flags */
77 : #define BTP_LEAF (1 << 0) /* leaf page, i.e. not internal page */
78 : #define BTP_ROOT (1 << 1) /* root page (has no parent) */
79 : #define BTP_DELETED (1 << 2) /* page has been deleted from tree */
80 : #define BTP_META (1 << 3) /* meta-page */
81 : #define BTP_HALF_DEAD (1 << 4) /* empty, but still in tree */
82 : #define BTP_SPLIT_END (1 << 5) /* rightmost page of split group */
83 : #define BTP_HAS_GARBAGE (1 << 6) /* page has LP_DEAD tuples (deprecated) */
84 : #define BTP_INCOMPLETE_SPLIT (1 << 7) /* right sibling's downlink is missing */
85 : #define BTP_HAS_FULLXID (1 << 8) /* contains BTDeletedPageData */
86 :
87 : /*
88 : * The max allowed value of a cycle ID is a bit less than 64K. This is
89 : * for convenience of pg_filedump and similar utilities: we want to use
90 : * the last 2 bytes of special space as an index type indicator, and
91 : * restricting cycle ID lets btree use that space for vacuum cycle IDs
92 : * while still allowing index type to be identified.
93 : */
94 : #define MAX_BT_CYCLE_ID 0xFF7F
95 :
96 :
97 : /*
98 : * The Meta page is always the first page in the btree index.
99 : * Its primary purpose is to point to the location of the btree root page.
100 : * We also point to the "fast" root, which is the current effective root;
101 : * see README for discussion.
102 : */
103 :
104 : typedef struct BTMetaPageData
105 : {
106 : uint32 btm_magic; /* should contain BTREE_MAGIC */
107 : uint32 btm_version; /* nbtree version (always <= BTREE_VERSION) */
108 : BlockNumber btm_root; /* current root location */
109 : uint32 btm_level; /* tree level of the root page */
110 : BlockNumber btm_fastroot; /* current "fast" root location */
111 : uint32 btm_fastlevel; /* tree level of the "fast" root page */
112 : /* remaining fields only valid when btm_version >= BTREE_NOVAC_VERSION */
113 :
114 : /* number of deleted, non-recyclable pages during last cleanup */
115 : uint32 btm_last_cleanup_num_delpages;
116 : /* number of heap tuples during last cleanup (deprecated) */
117 : float8 btm_last_cleanup_num_heap_tuples;
118 :
119 : bool btm_allequalimage; /* are all columns "equalimage"? */
120 : } BTMetaPageData;
121 :
122 : #define BTPageGetMeta(p) \
123 : ((BTMetaPageData *) PageGetContents(p))
124 :
125 : /*
126 : * The current Btree version is 4. That's what you'll get when you create
127 : * a new index.
128 : *
129 : * Btree version 3 was used in PostgreSQL v11. It is mostly the same as
130 : * version 4, but heap TIDs were not part of the keyspace. Index tuples
131 : * with duplicate keys could be stored in any order. We continue to
132 : * support reading and writing Btree versions 2 and 3, so that they don't
133 : * need to be immediately re-indexed at pg_upgrade. In order to get the
134 : * new heapkeyspace semantics, however, a REINDEX is needed.
135 : *
136 : * Deduplication is safe to use when the btm_allequalimage field is set to
137 : * true. It's safe to read the btm_allequalimage field on version 3, but
138 : * only version 4 indexes make use of deduplication. Even version 4
139 : * indexes created on PostgreSQL v12 will need a REINDEX to make use of
140 : * deduplication, though, since there is no other way to set
141 : * btm_allequalimage to true (pg_upgrade hasn't been taught to set the
142 : * metapage field).
143 : *
144 : * Btree version 2 is mostly the same as version 3. There are two new
145 : * fields in the metapage that were introduced in version 3. A version 2
146 : * metapage will be automatically upgraded to version 3 on the first
147 : * insert to it. INCLUDE indexes cannot use version 2.
148 : */
149 : #define BTREE_METAPAGE 0 /* first page is meta */
150 : #define BTREE_MAGIC 0x053162 /* magic number in metapage */
151 : #define BTREE_VERSION 4 /* current version number */
152 : #define BTREE_MIN_VERSION 2 /* minimum supported version */
153 : #define BTREE_NOVAC_VERSION 3 /* version with all meta fields set */
154 :
155 : /*
156 : * Maximum size of a btree index entry, including its tuple header.
157 : *
158 : * We actually need to be able to fit three items on every page,
159 : * so restrict any one item to 1/3 the per-page available space.
160 : *
161 : * There are rare cases where _bt_truncate() will need to enlarge
162 : * a heap index tuple to make space for a tiebreaker heap TID
163 : * attribute, which we account for here.
164 : */
165 : #define BTMaxItemSize \
166 : (MAXALIGN_DOWN((BLCKSZ - \
167 : MAXALIGN(SizeOfPageHeaderData + 3*sizeof(ItemIdData)) - \
168 : MAXALIGN(sizeof(BTPageOpaqueData))) / 3) - \
169 : MAXALIGN(sizeof(ItemPointerData)))
170 : #define BTMaxItemSizeNoHeapTid \
171 : MAXALIGN_DOWN((BLCKSZ - \
172 : MAXALIGN(SizeOfPageHeaderData + 3*sizeof(ItemIdData)) - \
173 : MAXALIGN(sizeof(BTPageOpaqueData))) / 3)
174 :
175 : /*
176 : * MaxTIDsPerBTreePage is an upper bound on the number of heap TIDs tuples
177 : * that may be stored on a btree leaf page. It is used to size the
178 : * per-page temporary buffers.
179 : *
180 : * Note: we don't bother considering per-tuple overheads here to keep
181 : * things simple (value is based on how many elements a single array of
182 : * heap TIDs must have to fill the space between the page header and
183 : * special area). The value is slightly higher (i.e. more conservative)
184 : * than necessary as a result, which is considered acceptable.
185 : */
186 : #define MaxTIDsPerBTreePage \
187 : (int) ((BLCKSZ - SizeOfPageHeaderData - sizeof(BTPageOpaqueData)) / \
188 : sizeof(ItemPointerData))
189 :
190 : /*
191 : * The leaf-page fillfactor defaults to 90% but is user-adjustable.
192 : * For pages above the leaf level, we use a fixed 70% fillfactor.
193 : * The fillfactor is applied during index build and when splitting
194 : * a rightmost page; when splitting non-rightmost pages we try to
195 : * divide the data equally. When splitting a page that's entirely
196 : * filled with a single value (duplicates), the effective leaf-page
197 : * fillfactor is 96%, regardless of whether the page is a rightmost
198 : * page.
199 : */
200 : #define BTREE_MIN_FILLFACTOR 10
201 : #define BTREE_DEFAULT_FILLFACTOR 90
202 : #define BTREE_NONLEAF_FILLFACTOR 70
203 : #define BTREE_SINGLEVAL_FILLFACTOR 96
204 :
205 : /*
206 : * In general, the btree code tries to localize its knowledge about
207 : * page layout to a couple of routines. However, we need a special
208 : * value to indicate "no page number" in those places where we expect
209 : * page numbers. We can use zero for this because we never need to
210 : * make a pointer to the metadata page.
211 : */
212 :
213 : #define P_NONE 0
214 :
215 : /*
216 : * Macros to test whether a page is leftmost or rightmost on its tree level,
217 : * as well as other state info kept in the opaque data.
218 : */
219 : #define P_LEFTMOST(opaque) ((opaque)->btpo_prev == P_NONE)
220 : #define P_RIGHTMOST(opaque) ((opaque)->btpo_next == P_NONE)
221 : #define P_ISLEAF(opaque) (((opaque)->btpo_flags & BTP_LEAF) != 0)
222 : #define P_ISROOT(opaque) (((opaque)->btpo_flags & BTP_ROOT) != 0)
223 : #define P_ISDELETED(opaque) (((opaque)->btpo_flags & BTP_DELETED) != 0)
224 : #define P_ISMETA(opaque) (((opaque)->btpo_flags & BTP_META) != 0)
225 : #define P_ISHALFDEAD(opaque) (((opaque)->btpo_flags & BTP_HALF_DEAD) != 0)
226 : #define P_IGNORE(opaque) (((opaque)->btpo_flags & (BTP_DELETED|BTP_HALF_DEAD)) != 0)
227 : #define P_HAS_GARBAGE(opaque) (((opaque)->btpo_flags & BTP_HAS_GARBAGE) != 0)
228 : #define P_INCOMPLETE_SPLIT(opaque) (((opaque)->btpo_flags & BTP_INCOMPLETE_SPLIT) != 0)
229 : #define P_HAS_FULLXID(opaque) (((opaque)->btpo_flags & BTP_HAS_FULLXID) != 0)
230 :
231 : /*
232 : * BTDeletedPageData is the page contents of a deleted page
233 : */
234 : typedef struct BTDeletedPageData
235 : {
236 : FullTransactionId safexid; /* See BTPageIsRecyclable() */
237 : } BTDeletedPageData;
238 :
239 : static inline void
240 3598 : BTPageSetDeleted(Page page, FullTransactionId safexid)
241 : {
242 : BTPageOpaque opaque;
243 : PageHeader header;
244 : BTDeletedPageData *contents;
245 :
246 3598 : opaque = BTPageGetOpaque(page);
247 3598 : header = ((PageHeader) page);
248 :
249 3598 : opaque->btpo_flags &= ~BTP_HALF_DEAD;
250 3598 : opaque->btpo_flags |= BTP_DELETED | BTP_HAS_FULLXID;
251 3598 : header->pd_lower = MAXALIGN(SizeOfPageHeaderData) +
252 : sizeof(BTDeletedPageData);
253 3598 : header->pd_upper = header->pd_special;
254 :
255 : /* Set safexid in deleted page */
256 3598 : contents = ((BTDeletedPageData *) PageGetContents(page));
257 3598 : contents->safexid = safexid;
258 3598 : }
259 :
260 : static inline FullTransactionId
261 410 : BTPageGetDeleteXid(Page page)
262 : {
263 : BTPageOpaque opaque;
264 : BTDeletedPageData *contents;
265 :
266 : /* We only expect to be called with a deleted page */
267 : Assert(!PageIsNew(page));
268 410 : opaque = BTPageGetOpaque(page);
269 : Assert(P_ISDELETED(opaque));
270 :
271 : /* pg_upgrade'd deleted page -- must be safe to recycle now */
272 410 : if (!P_HAS_FULLXID(opaque))
273 0 : return FirstNormalFullTransactionId;
274 :
275 : /* Get safexid from deleted page */
276 410 : contents = ((BTDeletedPageData *) PageGetContents(page));
277 410 : return contents->safexid;
278 : }
279 :
280 : /*
281 : * Is an existing page recyclable?
282 : *
283 : * This exists to centralize the policy on which deleted pages are now safe to
284 : * re-use. However, _bt_pendingfsm_finalize() duplicates some of the same
285 : * logic because it doesn't work directly with pages -- keep the two in sync.
286 : *
287 : * Note: PageIsNew() pages are always safe to recycle, but we can't deal with
288 : * them here (caller is responsible for that case themselves). Caller might
289 : * well need special handling for new pages anyway.
290 : */
291 : static inline bool
292 12525 : BTPageIsRecyclable(Page page, Relation heaprel)
293 : {
294 : BTPageOpaque opaque;
295 :
296 : Assert(!PageIsNew(page));
297 : Assert(heaprel != NULL);
298 :
299 : /* Recycling okay iff page is deleted and safexid is old enough */
300 12525 : opaque = BTPageGetOpaque(page);
301 12525 : if (P_ISDELETED(opaque))
302 : {
303 336 : FullTransactionId safexid = BTPageGetDeleteXid(page);
304 :
305 : /*
306 : * The page was deleted, but when? If it was just deleted, a scan
307 : * might have seen the downlink to it, and will read the page later.
308 : * As long as that can happen, we must keep the deleted page around as
309 : * a tombstone.
310 : *
311 : * For that check if the deletion XID could still be visible to
312 : * anyone. If not, then no scan that's still in progress could have
313 : * seen its downlink, and we can recycle it.
314 : */
315 336 : return GlobalVisCheckRemovableFullXid(heaprel, safexid);
316 : }
317 :
318 12189 : return false;
319 : }
320 :
321 : /*
322 : * BTVacState and BTPendingFSM are private nbtree.c state used during VACUUM.
323 : * They are exported for use by page deletion related code in nbtpage.c.
324 : */
325 : typedef struct BTPendingFSM
326 : {
327 : BlockNumber target; /* Page deleted by current VACUUM */
328 : FullTransactionId safexid; /* Page's BTDeletedPageData.safexid */
329 : } BTPendingFSM;
330 :
331 : typedef struct BTVacState
332 : {
333 : IndexVacuumInfo *info;
334 : IndexBulkDeleteResult *stats;
335 : IndexBulkDeleteCallback callback;
336 : void *callback_state;
337 : BTCycleId cycleid;
338 : MemoryContext pagedelcontext;
339 :
340 : /*
341 : * _bt_pendingfsm_finalize() state
342 : */
343 : int bufsize; /* pendingpages space (in # elements) */
344 : int maxbufsize; /* max bufsize that respects work_mem */
345 : BTPendingFSM *pendingpages; /* One entry per newly deleted page */
346 : int npendingpages; /* current # valid pendingpages */
347 : } BTVacState;
348 :
349 : /*
350 : * Lehman and Yao's algorithm requires a ``high key'' on every non-rightmost
351 : * page. The high key is not a tuple that is used to visit the heap. It is
352 : * a pivot tuple (see "Notes on B-Tree tuple format" below for definition).
353 : * The high key on a page is required to be greater than or equal to any
354 : * other key that appears on the page. If we find ourselves trying to
355 : * insert a key that is strictly > high key, we know we need to move right
356 : * (this should only happen if the page was split since we examined the
357 : * parent page).
358 : *
359 : * Our insertion algorithm guarantees that we can use the initial least key
360 : * on our right sibling as the high key. Once a page is created, its high
361 : * key changes only if the page is split.
362 : *
363 : * On a non-rightmost page, the high key lives in item 1 and data items
364 : * start in item 2. Rightmost pages have no high key, so we store data
365 : * items beginning in item 1.
366 : */
367 :
368 : #define P_HIKEY ((OffsetNumber) 1)
369 : #define P_FIRSTKEY ((OffsetNumber) 2)
370 : #define P_FIRSTDATAKEY(opaque) (P_RIGHTMOST(opaque) ? P_HIKEY : P_FIRSTKEY)
371 :
372 : /*
373 : * Notes on B-Tree tuple format, and key and non-key attributes:
374 : *
375 : * INCLUDE B-Tree indexes have non-key attributes. These are extra
376 : * attributes that may be returned by index-only scans, but do not influence
377 : * the order of items in the index (formally, non-key attributes are not
378 : * considered to be part of the key space). Non-key attributes are only
379 : * present in leaf index tuples whose item pointers actually point to heap
380 : * tuples (non-pivot tuples). _bt_check_natts() enforces the rules
381 : * described here.
382 : *
383 : * Non-pivot tuple format (plain/non-posting variant):
384 : *
385 : * t_tid | t_info | key values | INCLUDE columns, if any
386 : *
387 : * t_tid points to the heap TID, which is a tiebreaker key column as of
388 : * BTREE_VERSION 4.
389 : *
390 : * Non-pivot tuples complement pivot tuples, which only have key columns.
391 : * The sole purpose of pivot tuples is to represent how the key space is
392 : * separated. In general, any B-Tree index that has more than one level
393 : * (i.e. any index that does not just consist of a metapage and a single
394 : * leaf root page) must have some number of pivot tuples, since pivot
395 : * tuples are used for traversing the tree. Suffix truncation can omit
396 : * trailing key columns when a new pivot is formed, which makes minus
397 : * infinity their logical value. Since BTREE_VERSION 4 indexes treat heap
398 : * TID as a trailing key column that ensures that all index tuples are
399 : * physically unique, it is necessary to represent heap TID as a trailing
400 : * key column in pivot tuples, though very often this can be truncated
401 : * away, just like any other key column. (Actually, the heap TID is
402 : * omitted rather than truncated, since its representation is different to
403 : * the non-pivot representation.)
404 : *
405 : * Pivot tuple format:
406 : *
407 : * t_tid | t_info | key values | [heap TID]
408 : *
409 : * We store the number of columns present inside pivot tuples by abusing
410 : * their t_tid offset field, since pivot tuples never need to store a real
411 : * offset (pivot tuples generally store a downlink in t_tid, though). The
412 : * offset field only stores the number of columns/attributes when the
413 : * INDEX_ALT_TID_MASK bit is set, which doesn't count the trailing heap
414 : * TID column sometimes stored in pivot tuples -- that's represented by
415 : * the presence of BT_PIVOT_HEAP_TID_ATTR. The INDEX_ALT_TID_MASK bit in
416 : * t_info is always set on BTREE_VERSION 4 pivot tuples, since
417 : * BTreeTupleIsPivot() must work reliably on heapkeyspace versions.
418 : *
419 : * In version 2 or version 3 (!heapkeyspace) indexes, INDEX_ALT_TID_MASK
420 : * might not be set in pivot tuples. BTreeTupleIsPivot() won't work
421 : * reliably as a result. The number of columns stored is implicitly the
422 : * same as the number of columns in the index, just like any non-pivot
423 : * tuple. (The number of columns stored should not vary, since suffix
424 : * truncation of key columns is unsafe within any !heapkeyspace index.)
425 : *
426 : * The 12 least significant bits from t_tid's offset number are used to
427 : * represent the number of key columns within a pivot tuple. This leaves 4
428 : * status bits (BT_STATUS_OFFSET_MASK bits), which are shared by all tuples
429 : * that have the INDEX_ALT_TID_MASK bit set (set in t_info) to store basic
430 : * tuple metadata. BTreeTupleIsPivot() and BTreeTupleIsPosting() use the
431 : * BT_STATUS_OFFSET_MASK bits.
432 : *
433 : * Sometimes non-pivot tuples also use a representation that repurposes
434 : * t_tid to store metadata rather than a TID. PostgreSQL v13 introduced a
435 : * new non-pivot tuple format to support deduplication: posting list
436 : * tuples. Deduplication merges together multiple equal non-pivot tuples
437 : * into a logically equivalent, space efficient representation. A posting
438 : * list is an array of ItemPointerData elements. Non-pivot tuples are
439 : * merged together to form posting list tuples lazily, at the point where
440 : * we'd otherwise have to split a leaf page.
441 : *
442 : * Posting tuple format (alternative non-pivot tuple representation):
443 : *
444 : * t_tid | t_info | key values | posting list (TID array)
445 : *
446 : * Posting list tuples are recognized as such by having the
447 : * INDEX_ALT_TID_MASK status bit set in t_info and the BT_IS_POSTING status
448 : * bit set in t_tid's offset number. These flags redefine the content of
449 : * the posting tuple's t_tid to store the location of the posting list
450 : * (instead of a block number), as well as the total number of heap TIDs
451 : * present in the tuple (instead of a real offset number).
452 : *
453 : * The 12 least significant bits from t_tid's offset number are used to
454 : * represent the number of heap TIDs present in the tuple, leaving 4 status
455 : * bits (the BT_STATUS_OFFSET_MASK bits). Like any non-pivot tuple, the
456 : * number of columns stored is always implicitly the total number in the
457 : * index (in practice there can never be non-key columns stored, since
458 : * deduplication is not supported with INCLUDE indexes).
459 : */
460 : #define INDEX_ALT_TID_MASK INDEX_AM_RESERVED_BIT
461 :
462 : /* Item pointer offset bit masks */
463 : #define BT_OFFSET_MASK 0x0FFF
464 : #define BT_STATUS_OFFSET_MASK 0xF000
465 : /* BT_STATUS_OFFSET_MASK status bits */
466 : #define BT_PIVOT_HEAP_TID_ATTR 0x1000
467 : #define BT_IS_POSTING 0x2000
468 :
469 : /*
470 : * Mask allocated for number of keys in index tuple must be able to fit
471 : * maximum possible number of index attributes
472 : */
473 : StaticAssertDecl(BT_OFFSET_MASK >= INDEX_MAX_KEYS,
474 : "BT_OFFSET_MASK can't fit INDEX_MAX_KEYS");
475 :
476 : /*
477 : * Note: BTreeTupleIsPivot() can have false negatives (but not false
478 : * positives) when used with !heapkeyspace indexes
479 : */
480 : static inline bool
481 171133934 : BTreeTupleIsPivot(IndexTuple itup)
482 : {
483 171133934 : if ((itup->t_info & INDEX_ALT_TID_MASK) == 0)
484 124720269 : return false;
485 : /* absence of BT_IS_POSTING in offset number indicates pivot tuple */
486 46413665 : if ((ItemPointerGetOffsetNumberNoCheck(&itup->t_tid) & BT_IS_POSTING) != 0)
487 2328597 : return false;
488 :
489 44085068 : return true;
490 : }
491 :
492 : static inline bool
493 75690456 : BTreeTupleIsPosting(IndexTuple itup)
494 : {
495 75690456 : if ((itup->t_info & INDEX_ALT_TID_MASK) == 0)
496 69521048 : return false;
497 : /* presence of BT_IS_POSTING in offset number indicates posting tuple */
498 6169408 : if ((ItemPointerGetOffsetNumberNoCheck(&itup->t_tid) & BT_IS_POSTING) == 0)
499 173612 : return false;
500 :
501 5995796 : return true;
502 : }
503 :
504 : static inline void
505 264007 : BTreeTupleSetPosting(IndexTuple itup, uint16 nhtids, int postingoffset)
506 : {
507 : Assert(nhtids > 1);
508 : Assert((nhtids & BT_STATUS_OFFSET_MASK) == 0);
509 : Assert((size_t) postingoffset == MAXALIGN(postingoffset));
510 : Assert(postingoffset < INDEX_SIZE_MASK);
511 : Assert(!BTreeTupleIsPivot(itup));
512 :
513 264007 : itup->t_info |= INDEX_ALT_TID_MASK;
514 264007 : ItemPointerSetOffsetNumber(&itup->t_tid, (nhtids | BT_IS_POSTING));
515 264007 : ItemPointerSetBlockNumber(&itup->t_tid, postingoffset);
516 264007 : }
517 :
518 : static inline uint16
519 7110164 : BTreeTupleGetNPosting(IndexTuple posting)
520 : {
521 : OffsetNumber existing;
522 :
523 : Assert(BTreeTupleIsPosting(posting));
524 :
525 7110164 : existing = ItemPointerGetOffsetNumberNoCheck(&posting->t_tid);
526 7110164 : return (existing & BT_OFFSET_MASK);
527 : }
528 :
529 : static inline uint32
530 9601709 : BTreeTupleGetPostingOffset(IndexTuple posting)
531 : {
532 : Assert(BTreeTupleIsPosting(posting));
533 :
534 9601709 : return ItemPointerGetBlockNumberNoCheck(&posting->t_tid);
535 : }
536 :
537 : static inline ItemPointer
538 8325642 : BTreeTupleGetPosting(IndexTuple posting)
539 : {
540 16651284 : return (ItemPointer) ((char *) posting +
541 8325642 : BTreeTupleGetPostingOffset(posting));
542 : }
543 :
544 : static inline ItemPointer
545 6624103 : BTreeTupleGetPostingN(IndexTuple posting, int n)
546 : {
547 6624103 : return BTreeTupleGetPosting(posting) + n;
548 : }
549 :
550 : /*
551 : * Get/set downlink block number in pivot tuple.
552 : *
553 : * Note: Cannot assert that tuple is a pivot tuple. If we did so then
554 : * !heapkeyspace indexes would exhibit false positive assertion failures.
555 : */
556 : static inline BlockNumber
557 10033666 : BTreeTupleGetDownLink(IndexTuple pivot)
558 : {
559 10033666 : return ItemPointerGetBlockNumberNoCheck(&pivot->t_tid);
560 : }
561 :
562 : static inline void
563 37253 : BTreeTupleSetDownLink(IndexTuple pivot, BlockNumber blkno)
564 : {
565 37253 : ItemPointerSetBlockNumber(&pivot->t_tid, blkno);
566 37253 : }
567 :
568 : /*
569 : * Get number of attributes within tuple.
570 : *
571 : * Note that this does not include an implicit tiebreaker heap TID
572 : * attribute, if any. Note also that the number of key attributes must be
573 : * explicitly represented in all heapkeyspace pivot tuples.
574 : *
575 : * Note: This is defined as a macro rather than an inline function to
576 : * avoid including rel.h.
577 : */
578 : #define BTreeTupleGetNAtts(itup, rel) \
579 : ( \
580 : (BTreeTupleIsPivot(itup)) ? \
581 : ( \
582 : ItemPointerGetOffsetNumberNoCheck(&(itup)->t_tid) & BT_OFFSET_MASK \
583 : ) \
584 : : \
585 : IndexRelationGetNumberOfAttributes(rel) \
586 : )
587 :
588 : /*
589 : * Set number of key attributes in tuple.
590 : *
591 : * The heap TID tiebreaker attribute bit may also be set here, indicating that
592 : * a heap TID value will be stored at the end of the tuple (i.e. using the
593 : * special pivot tuple representation).
594 : */
595 : static inline void
596 44308 : BTreeTupleSetNAtts(IndexTuple itup, uint16 nkeyatts, bool heaptid)
597 : {
598 : Assert(nkeyatts <= INDEX_MAX_KEYS);
599 : Assert((nkeyatts & BT_STATUS_OFFSET_MASK) == 0);
600 : Assert(!heaptid || nkeyatts > 0);
601 : Assert(!BTreeTupleIsPivot(itup) || nkeyatts == 0);
602 :
603 44308 : itup->t_info |= INDEX_ALT_TID_MASK;
604 :
605 44308 : if (heaptid)
606 562 : nkeyatts |= BT_PIVOT_HEAP_TID_ATTR;
607 :
608 : /* BT_IS_POSTING bit is deliberately unset here */
609 44308 : ItemPointerSetOffsetNumber(&itup->t_tid, nkeyatts);
610 : Assert(BTreeTupleIsPivot(itup));
611 44308 : }
612 :
613 : /*
614 : * Get/set leaf page's "top parent" link from its high key. Used during page
615 : * deletion.
616 : *
617 : * Note: Cannot assert that tuple is a pivot tuple. If we did so then
618 : * !heapkeyspace indexes would exhibit false positive assertion failures.
619 : */
620 : static inline BlockNumber
621 2912 : BTreeTupleGetTopParent(IndexTuple leafhikey)
622 : {
623 2912 : return ItemPointerGetBlockNumberNoCheck(&leafhikey->t_tid);
624 : }
625 :
626 : static inline void
627 3599 : BTreeTupleSetTopParent(IndexTuple leafhikey, BlockNumber blkno)
628 : {
629 3599 : ItemPointerSetBlockNumber(&leafhikey->t_tid, blkno);
630 3599 : BTreeTupleSetNAtts(leafhikey, 0, false);
631 3599 : }
632 :
633 : /*
634 : * Get tiebreaker heap TID attribute, if any.
635 : *
636 : * This returns the first/lowest heap TID in the case of a posting list tuple.
637 : */
638 : static inline ItemPointer
639 18428538 : BTreeTupleGetHeapTID(IndexTuple itup)
640 : {
641 18428538 : if (BTreeTupleIsPivot(itup))
642 : {
643 : /* Pivot tuple heap TID representation? */
644 213955 : if ((ItemPointerGetOffsetNumberNoCheck(&itup->t_tid) &
645 : BT_PIVOT_HEAP_TID_ATTR) != 0)
646 163961 : return (ItemPointer) ((char *) itup + IndexTupleSize(itup) -
647 : sizeof(ItemPointerData));
648 :
649 : /* Heap TID attribute was truncated */
650 49994 : return NULL;
651 : }
652 18214583 : else if (BTreeTupleIsPosting(itup))
653 314702 : return BTreeTupleGetPosting(itup);
654 :
655 17899881 : return &itup->t_tid;
656 : }
657 :
658 : /*
659 : * Get maximum heap TID attribute, which could be the only TID in the case of
660 : * a non-pivot tuple that does not have a posting list.
661 : *
662 : * Works with non-pivot tuples only.
663 : */
664 : static inline ItemPointer
665 131549 : BTreeTupleGetMaxHeapTID(IndexTuple itup)
666 : {
667 : Assert(!BTreeTupleIsPivot(itup));
668 :
669 131549 : if (BTreeTupleIsPosting(itup))
670 : {
671 131286 : uint16 nposting = BTreeTupleGetNPosting(itup);
672 :
673 131286 : return BTreeTupleGetPostingN(itup, nposting - 1);
674 : }
675 :
676 263 : return &itup->t_tid;
677 : }
678 :
679 : /*
680 : * Operator strategy numbers for B-tree have been moved to access/stratnum.h,
681 : * because many places need to use them in ScanKeyInit() calls.
682 : *
683 : * The strategy numbers are chosen so that we can commute them by
684 : * subtraction, thus:
685 : */
686 : #define BTCommuteStrategyNumber(strat) (BTMaxStrategyNumber + 1 - (strat))
687 :
688 : /*
689 : * When a new operator class is declared, we require that the user
690 : * supply us with an amproc procedure (BTORDER_PROC) for determining
691 : * whether, for two keys a and b, a < b, a = b, or a > b. This routine
692 : * must return < 0, 0, > 0, respectively, in these three cases.
693 : *
694 : * To facilitate accelerated sorting, an operator class may choose to
695 : * offer a second procedure (BTSORTSUPPORT_PROC). For full details, see
696 : * src/include/utils/sortsupport.h.
697 : *
698 : * To support window frames defined by "RANGE offset PRECEDING/FOLLOWING",
699 : * an operator class may choose to offer a third amproc procedure
700 : * (BTINRANGE_PROC), independently of whether it offers sortsupport.
701 : * For full details, see doc/src/sgml/btree.sgml.
702 : *
703 : * To facilitate B-Tree deduplication, an operator class may choose to
704 : * offer a forth amproc procedure (BTEQUALIMAGE_PROC). For full details,
705 : * see doc/src/sgml/btree.sgml.
706 : *
707 : * An operator class may choose to offer a fifth amproc procedure
708 : * (BTOPTIONS_PROC). These procedures define a set of user-visible
709 : * parameters that can be used to control operator class behavior. None of
710 : * the built-in B-Tree operator classes currently register an "options" proc.
711 : *
712 : * To facilitate more efficient B-Tree skip scans, an operator class may
713 : * choose to offer a sixth amproc procedure (BTSKIPSUPPORT_PROC). For full
714 : * details, see src/include/utils/skipsupport.h.
715 : */
716 :
717 : #define BTORDER_PROC 1
718 : #define BTSORTSUPPORT_PROC 2
719 : #define BTINRANGE_PROC 3
720 : #define BTEQUALIMAGE_PROC 4
721 : #define BTOPTIONS_PROC 5
722 : #define BTSKIPSUPPORT_PROC 6
723 : #define BTNProcs 6
724 :
725 : /*
726 : * We need to be able to tell the difference between read and write
727 : * requests for pages, in order to do locking correctly.
728 : */
729 :
730 : #define BT_READ BUFFER_LOCK_SHARE
731 : #define BT_WRITE BUFFER_LOCK_EXCLUSIVE
732 :
733 : /*
734 : * BTStackData -- As we descend a tree, we push the location of pivot
735 : * tuples whose downlink we are about to follow onto a private stack. If
736 : * we split a leaf, we use this stack to walk back up the tree and insert
737 : * data into its parent page at the correct location. We also have to
738 : * recursively insert into the grandparent page if and when the parent page
739 : * splits. Our private stack can become stale due to concurrent page
740 : * splits and page deletions, but it should never give us an irredeemably
741 : * bad picture.
742 : */
743 : typedef struct BTStackData
744 : {
745 : BlockNumber bts_blkno;
746 : OffsetNumber bts_offset;
747 : struct BTStackData *bts_parent;
748 : } BTStackData;
749 :
750 : typedef BTStackData *BTStack;
751 :
752 : /*
753 : * BTScanInsertData is the btree-private state needed to find an initial
754 : * position for an indexscan, or to insert new tuples -- an "insertion
755 : * scankey" (not to be confused with a search scankey). It's used to descend
756 : * a B-Tree using _bt_search.
757 : *
758 : * heapkeyspace indicates if we expect all keys in the index to be physically
759 : * unique because heap TID is used as a tiebreaker attribute, and if index may
760 : * have truncated key attributes in pivot tuples. This is actually a property
761 : * of the index relation itself (not an indexscan). heapkeyspace indexes are
762 : * indexes whose version is >= version 4. It's convenient to keep this close
763 : * by, rather than accessing the metapage repeatedly.
764 : *
765 : * allequalimage is set to indicate that deduplication is safe for the index.
766 : * This is also a property of the index relation rather than an indexscan.
767 : *
768 : * anynullkeys indicates if any of the keys had NULL value when scankey was
769 : * built from index tuple (note that already-truncated tuple key attributes
770 : * set NULL as a placeholder key value, which also affects value of
771 : * anynullkeys). This is a convenience for unique index non-pivot tuple
772 : * insertion, which usually temporarily unsets scantid, but shouldn't iff
773 : * anynullkeys is true. Value generally matches non-pivot tuple's HasNulls
774 : * bit, but may not when inserting into an INCLUDE index (tuple header value
775 : * is affected by the NULL-ness of both key and non-key attributes).
776 : *
777 : * See comments in _bt_first for an explanation of the nextkey and backward
778 : * fields.
779 : *
780 : * scantid is the heap TID that is used as a final tiebreaker attribute. It
781 : * is set to NULL when index scan doesn't need to find a position for a
782 : * specific physical tuple. Must be set when inserting new tuples into
783 : * heapkeyspace indexes, since every tuple in the tree unambiguously belongs
784 : * in one exact position (it's never set with !heapkeyspace indexes, though).
785 : * Despite the representational difference, nbtree search code considers
786 : * scantid to be just another insertion scankey attribute.
787 : *
788 : * scankeys is an array of scan key entries for attributes that are compared
789 : * before scantid (user-visible attributes). keysz is the size of the array.
790 : * During insertion, there must be a scan key for every attribute, but when
791 : * starting a regular index scan some can be omitted. The array is used as a
792 : * flexible array member, though it's sized in a way that makes it possible to
793 : * use stack allocations. See nbtree/README for full details.
794 : */
795 : typedef struct BTScanInsertData
796 : {
797 : bool heapkeyspace;
798 : bool allequalimage;
799 : bool anynullkeys;
800 : bool nextkey;
801 : bool backward; /* backward index scan? */
802 : ItemPointer scantid; /* tiebreaker for scankeys */
803 : int keysz; /* Size of scankeys array */
804 : ScanKeyData scankeys[INDEX_MAX_KEYS]; /* Must appear last */
805 : } BTScanInsertData;
806 :
807 : typedef BTScanInsertData *BTScanInsert;
808 :
809 : /*
810 : * BTInsertStateData is a working area used during insertion.
811 : *
812 : * This is filled in after descending the tree to the first leaf page the new
813 : * tuple might belong on. Tracks the current position while performing
814 : * uniqueness check, before we have determined which exact page to insert
815 : * to.
816 : *
817 : * (This should be private to nbtinsert.c, but it's also used by
818 : * _bt_binsrch_insert)
819 : */
820 : typedef struct BTInsertStateData
821 : {
822 : IndexTuple itup; /* Item we're inserting */
823 : Size itemsz; /* Size of itup -- should be MAXALIGN()'d */
824 : BTScanInsert itup_key; /* Insertion scankey */
825 :
826 : /* Buffer containing leaf page we're likely to insert itup on */
827 : Buffer buf;
828 :
829 : /*
830 : * Cache of bounds within the current buffer. Only used for insertions
831 : * where _bt_check_unique is called. See _bt_binsrch_insert and
832 : * _bt_findinsertloc for details.
833 : */
834 : bool bounds_valid;
835 : OffsetNumber low;
836 : OffsetNumber stricthigh;
837 :
838 : /*
839 : * if _bt_binsrch_insert found the location inside existing posting list,
840 : * save the position inside the list. -1 sentinel value indicates overlap
841 : * with an existing posting list tuple that has its LP_DEAD bit set.
842 : */
843 : int postingoff;
844 : } BTInsertStateData;
845 :
846 : typedef BTInsertStateData *BTInsertState;
847 :
848 : /*
849 : * State used to representing an individual pending tuple during
850 : * deduplication.
851 : */
852 : typedef struct BTDedupInterval
853 : {
854 : OffsetNumber baseoff;
855 : uint16 nitems;
856 : } BTDedupInterval;
857 :
858 : /*
859 : * BTDedupStateData is a working area used during deduplication.
860 : *
861 : * The status info fields track the state of a whole-page deduplication pass.
862 : * State about the current pending posting list is also tracked.
863 : *
864 : * A pending posting list is comprised of a contiguous group of equal items
865 : * from the page, starting from page offset number 'baseoff'. This is the
866 : * offset number of the "base" tuple for new posting list. 'nitems' is the
867 : * current total number of existing items from the page that will be merged to
868 : * make a new posting list tuple, including the base tuple item. (Existing
869 : * items may themselves be posting list tuples, or regular non-pivot tuples.)
870 : *
871 : * The total size of the existing tuples to be freed when pending posting list
872 : * is processed gets tracked by 'phystupsize'. This information allows
873 : * deduplication to calculate the space saving for each new posting list
874 : * tuple, and for the entire pass over the page as a whole.
875 : */
876 : typedef struct BTDedupStateData
877 : {
878 : /* Deduplication status info for entire pass over page */
879 : bool deduplicate; /* Still deduplicating page? */
880 : int nmaxitems; /* Number of max-sized tuples so far */
881 : Size maxpostingsize; /* Limit on size of final tuple */
882 :
883 : /* Metadata about base tuple of current pending posting list */
884 : IndexTuple base; /* Use to form new posting list */
885 : OffsetNumber baseoff; /* page offset of base */
886 : Size basetupsize; /* base size without original posting list */
887 :
888 : /* Other metadata about pending posting list */
889 : ItemPointer htids; /* Heap TIDs in pending posting list */
890 : int nhtids; /* Number of heap TIDs in htids array */
891 : int nitems; /* Number of existing tuples/line pointers */
892 : Size phystupsize; /* Includes line pointer overhead */
893 :
894 : /*
895 : * Array of tuples to go on new version of the page. Contains one entry
896 : * for each group of consecutive items. Note that existing tuples that
897 : * will not become posting list tuples do not appear in the array (they
898 : * are implicitly unchanged by deduplication pass).
899 : */
900 : int nintervals; /* current number of intervals in array */
901 : BTDedupInterval intervals[MaxIndexTuplesPerPage];
902 : } BTDedupStateData;
903 :
904 : typedef BTDedupStateData *BTDedupState;
905 :
906 : /*
907 : * BTVacuumPostingData is state that represents how to VACUUM (or delete) a
908 : * posting list tuple when some (though not all) of its TIDs are to be
909 : * deleted.
910 : *
911 : * Convention is that itup field is the original posting list tuple on input,
912 : * and palloc()'d final tuple used to overwrite existing tuple on output.
913 : */
914 : typedef struct BTVacuumPostingData
915 : {
916 : /* Tuple that will be/was updated */
917 : IndexTuple itup;
918 : OffsetNumber updatedoffset;
919 :
920 : /* State needed to describe final itup in WAL */
921 : uint16 ndeletedtids;
922 : uint16 deletetids[FLEXIBLE_ARRAY_MEMBER];
923 : } BTVacuumPostingData;
924 :
925 : typedef BTVacuumPostingData *BTVacuumPosting;
926 :
927 : /*
928 : * BTScanOpaqueData is the btree-private state needed for an indexscan.
929 : * This consists of preprocessed scan keys (see _bt_preprocess_keys() for
930 : * details of the preprocessing), information about the current location
931 : * of the scan, and information about the marked location, if any. (We use
932 : * BTScanPosData to represent the data needed for each of current and marked
933 : * locations.) In addition we can remember some known-killed index entries
934 : * that must be marked before we can move off the current page.
935 : *
936 : * Index scans work a page at a time: we pin and read-lock the page, identify
937 : * all the matching items on the page and save them in BTScanPosData, then
938 : * release the read-lock while returning the items to the caller for
939 : * processing. This approach minimizes lock/unlock traffic. We must always
940 : * drop the lock to make it okay for caller to process the returned items.
941 : * Whether or not we can also release the pin during this window will vary.
942 : * We drop the pin (when so->dropPin) to avoid blocking progress by VACUUM
943 : * (see nbtree/README section about making concurrent TID recycling safe).
944 : * We'll always release both the lock and the pin on the current page before
945 : * moving on to its sibling page.
946 : *
947 : * If we are doing an index-only scan, we save the entire IndexTuple for each
948 : * matched item, otherwise only its heap TID and offset. The IndexTuples go
949 : * into a separate workspace array; each BTScanPosItem stores its tuple's
950 : * offset within that array. Posting list tuples store a "base" tuple once,
951 : * allowing the same key to be returned for each TID in the posting list
952 : * tuple.
953 : */
954 :
955 : typedef struct BTScanPosItem /* what we remember about each match */
956 : {
957 : ItemPointerData heapTid; /* TID of referenced heap item */
958 : OffsetNumber indexOffset; /* index item's location within page */
959 : LocationIndex tupleOffset; /* IndexTuple's offset in workspace, if any */
960 : } BTScanPosItem;
961 :
962 : typedef struct BTScanPosData
963 : {
964 : Buffer buf; /* currPage buf (invalid means unpinned) */
965 :
966 : /* page details as of the saved position's call to _bt_readpage */
967 : BlockNumber currPage; /* page referenced by items array */
968 : BlockNumber prevPage; /* currPage's left link */
969 : BlockNumber nextPage; /* currPage's right link */
970 : XLogRecPtr lsn; /* currPage's LSN (when so->dropPin) */
971 :
972 : /* scan direction for the saved position's call to _bt_readpage */
973 : ScanDirection dir;
974 :
975 : /*
976 : * If we are doing an index-only scan, nextTupleOffset is the first free
977 : * location in the associated tuple storage workspace.
978 : */
979 : int nextTupleOffset;
980 :
981 : /*
982 : * moreLeft and moreRight track whether we think there may be matching
983 : * index entries to the left and right of the current page, respectively.
984 : */
985 : bool moreLeft;
986 : bool moreRight;
987 :
988 : /*
989 : * The items array is always ordered in index order (ie, increasing
990 : * indexoffset). When scanning backwards it is convenient to fill the
991 : * array back-to-front, so we start at the last slot and fill downwards.
992 : * Hence we need both a first-valid-entry and a last-valid-entry counter.
993 : * itemIndex is a cursor showing which entry was last returned to caller.
994 : */
995 : int firstItem; /* first valid index in items[] */
996 : int lastItem; /* last valid index in items[] */
997 : int itemIndex; /* current index in items[] */
998 :
999 : BTScanPosItem items[MaxTIDsPerBTreePage]; /* MUST BE LAST */
1000 : } BTScanPosData;
1001 :
1002 : typedef BTScanPosData *BTScanPos;
1003 :
1004 : #define BTScanPosIsPinned(scanpos) \
1005 : ( \
1006 : AssertMacro(BlockNumberIsValid((scanpos).currPage) || \
1007 : !BufferIsValid((scanpos).buf)), \
1008 : BufferIsValid((scanpos).buf) \
1009 : )
1010 : #define BTScanPosUnpin(scanpos) \
1011 : do { \
1012 : ReleaseBuffer((scanpos).buf); \
1013 : (scanpos).buf = InvalidBuffer; \
1014 : } while (0)
1015 : #define BTScanPosUnpinIfPinned(scanpos) \
1016 : do { \
1017 : if (BTScanPosIsPinned(scanpos)) \
1018 : BTScanPosUnpin(scanpos); \
1019 : } while (0)
1020 :
1021 : #define BTScanPosIsValid(scanpos) \
1022 : ( \
1023 : AssertMacro(BlockNumberIsValid((scanpos).currPage) || \
1024 : !BufferIsValid((scanpos).buf)), \
1025 : BlockNumberIsValid((scanpos).currPage) \
1026 : )
1027 : #define BTScanPosInvalidate(scanpos) \
1028 : do { \
1029 : (scanpos).buf = InvalidBuffer; \
1030 : (scanpos).currPage = InvalidBlockNumber; \
1031 : } while (0)
1032 :
1033 : /* We need one of these for each equality-type SK_SEARCHARRAY scan key */
1034 : typedef struct BTArrayKeyInfo
1035 : {
1036 : /* fields set for both kinds of array (SAOP arrays and skip arrays) */
1037 : int scan_key; /* index of associated key in keyData */
1038 : int num_elems; /* number of elems (-1 means skip array) */
1039 :
1040 : /* fields set for ScalarArrayOpExpr arrays only */
1041 : Datum *elem_values; /* array of num_elems Datums */
1042 : int cur_elem; /* index of current element in elem_values */
1043 :
1044 : /* fields set for skip arrays only */
1045 : int16 attlen; /* attr's length, in bytes */
1046 : bool attbyval; /* attr's FormData_pg_attribute.attbyval */
1047 : bool null_elem; /* NULL is lowest/highest element? */
1048 : SkipSupport sksup; /* skip support (NULL if opclass lacks it) */
1049 : ScanKey low_compare; /* array's > or >= lower bound */
1050 : ScanKey high_compare; /* array's < or <= upper bound */
1051 : } BTArrayKeyInfo;
1052 :
1053 : typedef struct BTScanOpaqueData
1054 : {
1055 : /* these fields are set by _bt_preprocess_keys(): */
1056 : bool qual_ok; /* false if qual can never be satisfied */
1057 : int numberOfKeys; /* number of preprocessed scan keys */
1058 : ScanKey keyData; /* array of preprocessed scan keys */
1059 :
1060 : /* workspace for SK_SEARCHARRAY support */
1061 : int numArrayKeys; /* number of equality-type array keys */
1062 : bool skipScan; /* At least one skip array in arrayKeys[]? */
1063 : bool needPrimScan; /* New prim scan to continue in current dir? */
1064 : bool scanBehind; /* Check scan not still behind on next page? */
1065 : bool oppositeDirCheck; /* scanBehind opposite-scan-dir check? */
1066 : BTArrayKeyInfo *arrayKeys; /* info about each equality-type array key */
1067 : FmgrInfo *orderProcs; /* ORDER procs for required equality keys */
1068 : MemoryContext arrayContext; /* scan-lifespan context for array data */
1069 :
1070 : /* info about killed items if any (killedItems is NULL if never used) */
1071 : int *killedItems; /* currPos.items indexes of killed items */
1072 : int numKilled; /* number of currently stored items */
1073 : bool dropPin; /* drop leaf pin before btgettuple returns? */
1074 :
1075 : /*
1076 : * If we are doing an index-only scan, these are the tuple storage
1077 : * workspaces for the currPos and markPos respectively. Each is of size
1078 : * BLCKSZ, so it can hold as much as a full page's worth of tuples.
1079 : */
1080 : char *currTuples; /* tuple storage for currPos */
1081 : char *markTuples; /* tuple storage for markPos */
1082 :
1083 : /*
1084 : * If the marked position is on the same page as current position, we
1085 : * don't use markPos, but just keep the marked itemIndex in markItemIndex
1086 : * (all the rest of currPos is valid for the mark position). Hence, to
1087 : * determine if there is a mark, first look at markItemIndex, then at
1088 : * markPos.
1089 : */
1090 : int markItemIndex; /* itemIndex, or -1 if not valid */
1091 :
1092 : /* keep these last in struct for efficiency */
1093 : BTScanPosData currPos; /* current position data */
1094 : BTScanPosData markPos; /* marked position, if any */
1095 : } BTScanOpaqueData;
1096 :
1097 : typedef BTScanOpaqueData *BTScanOpaque;
1098 :
1099 : /*
1100 : * We use some private sk_flags bits in preprocessed scan keys. We're allowed
1101 : * to use bits 16-31 (see skey.h). The uppermost bits are copied from the
1102 : * index's indoption[] array entry for the index attribute.
1103 : */
1104 : #define SK_BT_REQFWD 0x00010000 /* required to continue forward scan */
1105 : #define SK_BT_REQBKWD 0x00020000 /* required to continue backward scan */
1106 : #define SK_BT_SKIP 0x00040000 /* skip array on column without input = */
1107 :
1108 : /* SK_BT_SKIP-only flags (set and unset by array advancement) */
1109 : #define SK_BT_MINVAL 0x00080000 /* invalid sk_argument, use low_compare */
1110 : #define SK_BT_MAXVAL 0x00100000 /* invalid sk_argument, use high_compare */
1111 : #define SK_BT_NEXT 0x00200000 /* positions the scan > sk_argument */
1112 : #define SK_BT_PRIOR 0x00400000 /* positions the scan < sk_argument */
1113 :
1114 : /* Remaps pg_index flag bits to uppermost SK_BT_* byte */
1115 : #define SK_BT_INDOPTION_SHIFT 24 /* must clear the above bits */
1116 : #define SK_BT_DESC (INDOPTION_DESC << SK_BT_INDOPTION_SHIFT)
1117 : #define SK_BT_NULLS_FIRST (INDOPTION_NULLS_FIRST << SK_BT_INDOPTION_SHIFT)
1118 :
1119 : typedef struct BTOptions
1120 : {
1121 : int32 varlena_header_; /* varlena header (do not touch directly!) */
1122 : int fillfactor; /* page fill factor in percent (0..100) */
1123 : float8 vacuum_cleanup_index_scale_factor; /* deprecated */
1124 : bool deduplicate_items; /* Try to deduplicate items? */
1125 : } BTOptions;
1126 :
1127 : #define BTGetFillFactor(relation) \
1128 : (AssertMacro(relation->rd_rel->relkind == RELKIND_INDEX && \
1129 : relation->rd_rel->relam == BTREE_AM_OID), \
1130 : (relation)->rd_options ? \
1131 : ((BTOptions *) (relation)->rd_options)->fillfactor : \
1132 : BTREE_DEFAULT_FILLFACTOR)
1133 : #define BTGetTargetPageFreeSpace(relation) \
1134 : (BLCKSZ * (100 - BTGetFillFactor(relation)) / 100)
1135 : #define BTGetDeduplicateItems(relation) \
1136 : (AssertMacro(relation->rd_rel->relkind == RELKIND_INDEX && \
1137 : relation->rd_rel->relam == BTREE_AM_OID), \
1138 : ((relation)->rd_options ? \
1139 : ((BTOptions *) (relation)->rd_options)->deduplicate_items : true))
1140 :
1141 : /*
1142 : * Constant definition for progress reporting. Phase numbers must match
1143 : * btbuildphasename.
1144 : */
1145 : /* PROGRESS_CREATEIDX_SUBPHASE_INITIALIZE is 1 (see progress.h) */
1146 : #define PROGRESS_BTREE_PHASE_INDEXBUILD_TABLESCAN 2
1147 : #define PROGRESS_BTREE_PHASE_PERFORMSORT_1 3
1148 : #define PROGRESS_BTREE_PHASE_PERFORMSORT_2 4
1149 : #define PROGRESS_BTREE_PHASE_LEAF_LOAD 5
1150 :
1151 : /*
1152 : * external entry points for btree, in nbtree.c
1153 : */
1154 : extern void btbuildempty(Relation index);
1155 : extern bool btinsert(Relation rel, Datum *values, bool *isnull,
1156 : ItemPointer ht_ctid, Relation heapRel,
1157 : IndexUniqueCheck checkUnique,
1158 : bool indexUnchanged,
1159 : struct IndexInfo *indexInfo);
1160 : extern IndexScanDesc btbeginscan(Relation rel, int nkeys, int norderbys);
1161 : extern Size btestimateparallelscan(Relation rel, int nkeys, int norderbys);
1162 : extern void btinitparallelscan(void *target);
1163 : extern bool btgettuple(IndexScanDesc scan, ScanDirection dir);
1164 : extern int64 btgetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
1165 : extern void btrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
1166 : ScanKey orderbys, int norderbys);
1167 : extern void btparallelrescan(IndexScanDesc scan);
1168 : extern void btendscan(IndexScanDesc scan);
1169 : extern void btmarkpos(IndexScanDesc scan);
1170 : extern void btrestrpos(IndexScanDesc scan);
1171 : extern IndexBulkDeleteResult *btbulkdelete(IndexVacuumInfo *info,
1172 : IndexBulkDeleteResult *stats,
1173 : IndexBulkDeleteCallback callback,
1174 : void *callback_state);
1175 : extern IndexBulkDeleteResult *btvacuumcleanup(IndexVacuumInfo *info,
1176 : IndexBulkDeleteResult *stats);
1177 : extern bool btcanreturn(Relation index, int attno);
1178 : extern int btgettreeheight(Relation rel);
1179 :
1180 : extern CompareType bttranslatestrategy(StrategyNumber strategy, Oid opfamily);
1181 : extern StrategyNumber bttranslatecmptype(CompareType cmptype, Oid opfamily);
1182 :
1183 : /*
1184 : * prototypes for internal functions in nbtree.c
1185 : */
1186 : extern bool _bt_parallel_seize(IndexScanDesc scan, BlockNumber *next_scan_page,
1187 : BlockNumber *last_curr_page, bool first);
1188 : extern void _bt_parallel_release(IndexScanDesc scan,
1189 : BlockNumber next_scan_page,
1190 : BlockNumber curr_page);
1191 : extern void _bt_parallel_done(IndexScanDesc scan);
1192 : extern void _bt_parallel_primscan_schedule(IndexScanDesc scan,
1193 : BlockNumber curr_page);
1194 :
1195 : /*
1196 : * prototypes for functions in nbtdedup.c
1197 : */
1198 : extern void _bt_dedup_pass(Relation rel, Buffer buf, IndexTuple newitem,
1199 : Size newitemsz, bool bottomupdedup);
1200 : extern bool _bt_bottomupdel_pass(Relation rel, Buffer buf, Relation heapRel,
1201 : Size newitemsz);
1202 : extern void _bt_dedup_start_pending(BTDedupState state, IndexTuple base,
1203 : OffsetNumber baseoff);
1204 : extern bool _bt_dedup_save_htid(BTDedupState state, IndexTuple itup);
1205 : extern Size _bt_dedup_finish_pending(Page newpage, BTDedupState state);
1206 : extern IndexTuple _bt_form_posting(IndexTuple base, const ItemPointerData *htids,
1207 : int nhtids);
1208 : extern void _bt_update_posting(BTVacuumPosting vacposting);
1209 : extern IndexTuple _bt_swap_posting(IndexTuple newitem, IndexTuple oposting,
1210 : int postingoff);
1211 :
1212 : /*
1213 : * prototypes for functions in nbtinsert.c
1214 : */
1215 : extern bool _bt_doinsert(Relation rel, IndexTuple itup,
1216 : IndexUniqueCheck checkUnique, bool indexUnchanged,
1217 : Relation heapRel);
1218 : extern void _bt_finish_split(Relation rel, Relation heaprel, Buffer lbuf,
1219 : BTStack stack);
1220 : extern Buffer _bt_getstackbuf(Relation rel, Relation heaprel, BTStack stack,
1221 : BlockNumber child);
1222 :
1223 : /*
1224 : * prototypes for functions in nbtsplitloc.c
1225 : */
1226 : extern OffsetNumber _bt_findsplitloc(Relation rel, Page origpage,
1227 : OffsetNumber newitemoff, Size newitemsz, IndexTuple newitem,
1228 : bool *newitemonleft);
1229 :
1230 : /*
1231 : * prototypes for functions in nbtpage.c
1232 : */
1233 : extern void _bt_initmetapage(Page page, BlockNumber rootbknum, uint32 level,
1234 : bool allequalimage);
1235 : extern bool _bt_vacuum_needs_cleanup(Relation rel);
1236 : extern void _bt_set_cleanup_info(Relation rel, BlockNumber num_delpages);
1237 : extern void _bt_upgrademetapage(Page page);
1238 : extern Buffer _bt_getroot(Relation rel, Relation heaprel, int access);
1239 : extern Buffer _bt_gettrueroot(Relation rel);
1240 : extern int _bt_getrootheight(Relation rel);
1241 : extern void _bt_metaversion(Relation rel, bool *heapkeyspace,
1242 : bool *allequalimage);
1243 : extern void _bt_checkpage(Relation rel, Buffer buf);
1244 : extern Buffer _bt_getbuf(Relation rel, BlockNumber blkno, int access);
1245 : extern Buffer _bt_allocbuf(Relation rel, Relation heaprel);
1246 : extern Buffer _bt_relandgetbuf(Relation rel, Buffer obuf,
1247 : BlockNumber blkno, int access);
1248 : extern void _bt_relbuf(Relation rel, Buffer buf);
1249 : extern void _bt_lockbuf(Relation rel, Buffer buf, int access);
1250 : extern void _bt_unlockbuf(Relation rel, Buffer buf);
1251 : extern bool _bt_conditionallockbuf(Relation rel, Buffer buf);
1252 : extern void _bt_upgradelockbufcleanup(Relation rel, Buffer buf);
1253 : extern void _bt_pageinit(Page page, Size size);
1254 : extern void _bt_delitems_vacuum(Relation rel, Buffer buf,
1255 : OffsetNumber *deletable, int ndeletable,
1256 : BTVacuumPosting *updatable, int nupdatable);
1257 : struct TM_IndexDeleteOp; /* avoid including tableam.h here */
1258 : extern void _bt_delitems_delete_check(Relation rel, Buffer buf,
1259 : Relation heapRel,
1260 : struct TM_IndexDeleteOp *delstate);
1261 : extern void _bt_pagedel(Relation rel, Buffer leafbuf, BTVacState *vstate);
1262 : extern void _bt_pendingfsm_init(Relation rel, BTVacState *vstate,
1263 : bool cleanuponly);
1264 : extern void _bt_pendingfsm_finalize(Relation rel, BTVacState *vstate);
1265 :
1266 : /*
1267 : * prototypes for functions in nbtpreprocesskeys.c
1268 : */
1269 : extern void _bt_preprocess_keys(IndexScanDesc scan);
1270 :
1271 : /*
1272 : * prototypes for functions in nbtreadpage.c
1273 : */
1274 : extern bool _bt_readpage(IndexScanDesc scan, ScanDirection dir,
1275 : OffsetNumber offnum, bool firstpage);
1276 : extern void _bt_start_array_keys(IndexScanDesc scan, ScanDirection dir);
1277 : extern int _bt_binsrch_array_skey(FmgrInfo *orderproc,
1278 : bool cur_elem_trig, ScanDirection dir,
1279 : Datum tupdatum, bool tupnull,
1280 : BTArrayKeyInfo *array, ScanKey cur,
1281 : int32 *set_elem_result);
1282 :
1283 : /*
1284 : * prototypes for functions in nbtsearch.c
1285 : */
1286 : extern BTStack _bt_search(Relation rel, Relation heaprel, BTScanInsert key,
1287 : Buffer *bufP, int access);
1288 : extern OffsetNumber _bt_binsrch_insert(Relation rel, BTInsertState insertstate);
1289 : extern int32 _bt_compare(Relation rel, BTScanInsert key, Page page, OffsetNumber offnum);
1290 : extern bool _bt_first(IndexScanDesc scan, ScanDirection dir);
1291 : extern bool _bt_next(IndexScanDesc scan, ScanDirection dir);
1292 : extern Buffer _bt_get_endpoint(Relation rel, uint32 level, bool rightmost);
1293 :
1294 : /*
1295 : * prototypes for functions in nbtutils.c
1296 : */
1297 : extern BTScanInsert _bt_mkscankey(Relation rel, IndexTuple itup);
1298 : extern void _bt_freestack(BTStack stack);
1299 : extern void _bt_killitems(IndexScanDesc scan);
1300 : extern BTCycleId _bt_vacuum_cycleid(Relation rel);
1301 : extern BTCycleId _bt_start_vacuum(Relation rel);
1302 : extern void _bt_end_vacuum(Relation rel);
1303 : extern void _bt_end_vacuum_callback(int code, Datum arg);
1304 : extern Size BTreeShmemSize(void);
1305 : extern void BTreeShmemInit(void);
1306 : extern bytea *btoptions(Datum reloptions, bool validate);
1307 : extern bool btproperty(Oid index_oid, int attno,
1308 : IndexAMProperty prop, const char *propname,
1309 : bool *res, bool *isnull);
1310 : extern char *btbuildphasename(int64 phasenum);
1311 : extern IndexTuple _bt_truncate(Relation rel, IndexTuple lastleft,
1312 : IndexTuple firstright, BTScanInsert itup_key);
1313 : extern int _bt_keep_natts_fast(Relation rel, IndexTuple lastleft,
1314 : IndexTuple firstright);
1315 : extern bool _bt_check_natts(Relation rel, bool heapkeyspace, Page page,
1316 : OffsetNumber offnum);
1317 : extern void _bt_check_third_page(Relation rel, Relation heap,
1318 : bool needheaptidspace, Page page, IndexTuple newtup);
1319 : extern bool _bt_allequalimage(Relation rel, bool debugmessage);
1320 :
1321 : /*
1322 : * prototypes for functions in nbtvalidate.c
1323 : */
1324 : extern bool btvalidate(Oid opclassoid);
1325 : extern void btadjustmembers(Oid opfamilyoid,
1326 : Oid opclassoid,
1327 : List *operators,
1328 : List *functions);
1329 :
1330 : /*
1331 : * prototypes for functions in nbtsort.c
1332 : */
1333 : extern IndexBuildResult *btbuild(Relation heap, Relation index,
1334 : struct IndexInfo *indexInfo);
1335 : extern void _bt_parallel_build_main(dsm_segment *seg, shm_toc *toc);
1336 :
1337 : #endif /* NBTREE_H */
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