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htup_details.h
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1/*-------------------------------------------------------------------------
2 *
3 * htup_details.h
4 * POSTGRES heap tuple header definitions.
5 *
6 *
7 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
9 *
10 * src/include/access/htup_details.h
11 *
12 *-------------------------------------------------------------------------
13 */
14#ifndef HTUP_DETAILS_H
15#define HTUP_DETAILS_H
16
17#include "access/htup.h"
18#include "access/transam.h"
19#include "access/tupdesc.h"
20#include "access/tupmacs.h"
21#include "storage/bufpage.h"
22#include "varatt.h"
23
24/*
25 * MaxTupleAttributeNumber limits the number of (user) columns in a tuple.
26 * The key limit on this value is that the size of the fixed overhead for
27 * a tuple, plus the size of the null-values bitmap (at 1 bit per column),
28 * plus MAXALIGN alignment, must fit into t_hoff which is uint8. On most
29 * machines the upper limit without making t_hoff wider would be a little
30 * over 1700. We use round numbers here and for MaxHeapAttributeNumber
31 * so that alterations in HeapTupleHeaderData layout won't change the
32 * supported max number of columns.
33 */
34#define MaxTupleAttributeNumber 1664 /* 8 * 208 */
35
36/*
37 * MaxHeapAttributeNumber limits the number of (user) columns in a table.
38 * This should be somewhat less than MaxTupleAttributeNumber. It must be
39 * at least one less, else we will fail to do UPDATEs on a maximal-width
40 * table (because UPDATE has to form working tuples that include CTID).
41 * In practice we want some additional daylight so that we can gracefully
42 * support operations that add hidden "resjunk" columns, for example
43 * SELECT * FROM wide_table ORDER BY foo, bar, baz.
44 * In any case, depending on column data types you will likely be running
45 * into the disk-block-based limit on overall tuple size if you have more
46 * than a thousand or so columns. TOAST won't help.
47 */
48#define MaxHeapAttributeNumber 1600 /* 8 * 200 */
49
50/*
51 * Heap tuple header. To avoid wasting space, the fields should be
52 * laid out in such a way as to avoid structure padding.
53 *
54 * Datums of composite types (row types) share the same general structure
55 * as on-disk tuples, so that the same routines can be used to build and
56 * examine them. However the requirements are slightly different: a Datum
57 * does not need any transaction visibility information, and it does need
58 * a length word and some embedded type information. We can achieve this
59 * by overlaying the xmin/cmin/xmax/cmax/xvac fields of a heap tuple
60 * with the fields needed in the Datum case. Typically, all tuples built
61 * in-memory will be initialized with the Datum fields; but when a tuple is
62 * about to be inserted in a table, the transaction fields will be filled,
63 * overwriting the datum fields.
64 *
65 * The overall structure of a heap tuple looks like:
66 * fixed fields (HeapTupleHeaderData struct)
67 * nulls bitmap (if HEAP_HASNULL is set in t_infomask)
68 * alignment padding (as needed to make user data MAXALIGN'd)
69 * object ID (if HEAP_HASOID_OLD is set in t_infomask, not created
70 * anymore)
71 * user data fields
72 *
73 * We store five "virtual" fields Xmin, Cmin, Xmax, Cmax, and Xvac in three
74 * physical fields. Xmin and Xmax are always really stored, but Cmin, Cmax
75 * and Xvac share a field. This works because we know that Cmin and Cmax
76 * are only interesting for the lifetime of the inserting and deleting
77 * transaction respectively. If a tuple is inserted and deleted in the same
78 * transaction, we store a "combo" command id that can be mapped to the real
79 * cmin and cmax, but only by use of local state within the originating
80 * backend. See combocid.c for more details. Meanwhile, Xvac is only set by
81 * old-style VACUUM FULL, which does not have any command sub-structure and so
82 * does not need either Cmin or Cmax. (This requires that old-style VACUUM
83 * FULL never try to move a tuple whose Cmin or Cmax is still interesting,
84 * ie, an insert-in-progress or delete-in-progress tuple.)
85 *
86 * A word about t_ctid: whenever a new tuple is stored on disk, its t_ctid
87 * is initialized with its own TID (location). If the tuple is ever updated,
88 * its t_ctid is changed to point to the replacement version of the tuple. Or
89 * if the tuple is moved from one partition to another, due to an update of
90 * the partition key, t_ctid is set to a special value to indicate that
91 * (see ItemPointerSetMovedPartitions). Thus, a tuple is the latest version
92 * of its row iff XMAX is invalid or
93 * t_ctid points to itself (in which case, if XMAX is valid, the tuple is
94 * either locked or deleted). One can follow the chain of t_ctid links
95 * to find the newest version of the row, unless it was moved to a different
96 * partition. Beware however that VACUUM might
97 * erase the pointed-to (newer) tuple before erasing the pointing (older)
98 * tuple. Hence, when following a t_ctid link, it is necessary to check
99 * to see if the referenced slot is empty or contains an unrelated tuple.
100 * Check that the referenced tuple has XMIN equal to the referencing tuple's
101 * XMAX to verify that it is actually the descendant version and not an
102 * unrelated tuple stored into a slot recently freed by VACUUM. If either
103 * check fails, one may assume that there is no live descendant version.
104 *
105 * t_ctid is sometimes used to store a speculative insertion token, instead
106 * of a real TID. A speculative token is set on a tuple that's being
107 * inserted, until the inserter is sure that it wants to go ahead with the
108 * insertion. Hence a token should only be seen on a tuple with an XMAX
109 * that's still in-progress, or invalid/aborted. The token is replaced with
110 * the tuple's real TID when the insertion is confirmed. One should never
111 * see a speculative insertion token while following a chain of t_ctid links,
112 * because they are not used on updates, only insertions.
113 *
114 * Following the fixed header fields, the nulls bitmap is stored (beginning
115 * at t_bits). The bitmap is *not* stored if t_infomask shows that there
116 * are no nulls in the tuple. If an OID field is present (as indicated by
117 * t_infomask), then it is stored just before the user data, which begins at
118 * the offset shown by t_hoff. Note that t_hoff must be a multiple of
119 * MAXALIGN.
120 */
121
122typedef struct HeapTupleFields
123{
124 TransactionId t_xmin; /* inserting xact ID */
125 TransactionId t_xmax; /* deleting or locking xact ID */
126
127 union
128 {
129 CommandId t_cid; /* inserting or deleting command ID, or both */
130 TransactionId t_xvac; /* old-style VACUUM FULL xact ID */
133
134typedef struct DatumTupleFields
135{
136 int32 datum_len_; /* varlena header (do not touch directly!) */
137
138 int32 datum_typmod; /* -1, or identifier of a record type */
139
140 Oid datum_typeid; /* composite type OID, or RECORDOID */
141
142 /*
143 * datum_typeid cannot be a domain over composite, only plain composite,
144 * even if the datum is meant as a value of a domain-over-composite type.
145 * This is in line with the general principle that CoerceToDomain does not
146 * change the physical representation of the base type value.
147 *
148 * Note: field ordering is chosen with thought that Oid might someday
149 * widen to 64 bits.
150 */
152
154{
155 union
156 {
160
161 ItemPointerData t_ctid; /* current TID of this or newer tuple (or a
162 * speculative insertion token) */
163
164 /* Fields below here must match MinimalTupleData! */
165
166#define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK2 2
167 uint16 t_infomask2; /* number of attributes + various flags */
168
169#define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK 3
170 uint16 t_infomask; /* various flag bits, see below */
171
172#define FIELDNO_HEAPTUPLEHEADERDATA_HOFF 4
173 uint8 t_hoff; /* sizeof header incl. bitmap, padding */
174
175 /* ^ - 23 bytes - ^ */
176
177#define FIELDNO_HEAPTUPLEHEADERDATA_BITS 5
178 bits8 t_bits[FLEXIBLE_ARRAY_MEMBER]; /* bitmap of NULLs */
179
180 /* MORE DATA FOLLOWS AT END OF STRUCT */
181};
182
183/* typedef appears in htup.h */
184
185#define SizeofHeapTupleHeader offsetof(HeapTupleHeaderData, t_bits)
186
187/*
188 * information stored in t_infomask:
189 */
190#define HEAP_HASNULL 0x0001 /* has null attribute(s) */
191#define HEAP_HASVARWIDTH 0x0002 /* has variable-width attribute(s) */
192#define HEAP_HASEXTERNAL 0x0004 /* has external stored attribute(s) */
193#define HEAP_HASOID_OLD 0x0008 /* has an object-id field */
194#define HEAP_XMAX_KEYSHR_LOCK 0x0010 /* xmax is a key-shared locker */
195#define HEAP_COMBOCID 0x0020 /* t_cid is a combo CID */
196#define HEAP_XMAX_EXCL_LOCK 0x0040 /* xmax is exclusive locker */
197#define HEAP_XMAX_LOCK_ONLY 0x0080 /* xmax, if valid, is only a locker */
198
199 /* xmax is a shared locker */
200#define HEAP_XMAX_SHR_LOCK (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)
201
202#define HEAP_LOCK_MASK (HEAP_XMAX_SHR_LOCK | HEAP_XMAX_EXCL_LOCK | \
203 HEAP_XMAX_KEYSHR_LOCK)
204#define HEAP_XMIN_COMMITTED 0x0100 /* t_xmin committed */
205#define HEAP_XMIN_INVALID 0x0200 /* t_xmin invalid/aborted */
206#define HEAP_XMIN_FROZEN (HEAP_XMIN_COMMITTED|HEAP_XMIN_INVALID)
207#define HEAP_XMAX_COMMITTED 0x0400 /* t_xmax committed */
208#define HEAP_XMAX_INVALID 0x0800 /* t_xmax invalid/aborted */
209#define HEAP_XMAX_IS_MULTI 0x1000 /* t_xmax is a MultiXactId */
210#define HEAP_UPDATED 0x2000 /* this is UPDATEd version of row */
211#define HEAP_MOVED_OFF 0x4000 /* moved to another place by pre-9.0
212 * VACUUM FULL; kept for binary
213 * upgrade support */
214#define HEAP_MOVED_IN 0x8000 /* moved from another place by pre-9.0
215 * VACUUM FULL; kept for binary
216 * upgrade support */
217#define HEAP_MOVED (HEAP_MOVED_OFF | HEAP_MOVED_IN)
218
219#define HEAP_XACT_MASK 0xFFF0 /* visibility-related bits */
220
221/*
222 * A tuple is only locked (i.e. not updated by its Xmax) if the
223 * HEAP_XMAX_LOCK_ONLY bit is set; or, for pg_upgrade's sake, if the Xmax is
224 * not a multi and the EXCL_LOCK bit is set.
225 *
226 * See also HeapTupleHeaderIsOnlyLocked, which also checks for a possible
227 * aborted updater transaction.
228 */
229static inline bool
231{
232 return (infomask & HEAP_XMAX_LOCK_ONLY) ||
234}
235
236/*
237 * A tuple that has HEAP_XMAX_IS_MULTI and HEAP_XMAX_LOCK_ONLY but neither of
238 * HEAP_XMAX_EXCL_LOCK and HEAP_XMAX_KEYSHR_LOCK must come from a tuple that was
239 * share-locked in 9.2 or earlier and then pg_upgrade'd.
240 *
241 * In 9.2 and prior, HEAP_XMAX_IS_MULTI was only set when there were multiple
242 * FOR SHARE lockers of that tuple. That set HEAP_XMAX_LOCK_ONLY (with a
243 * different name back then) but neither of HEAP_XMAX_EXCL_LOCK and
244 * HEAP_XMAX_KEYSHR_LOCK. That combination is no longer possible in 9.3 and
245 * up, so if we see that combination we know for certain that the tuple was
246 * locked in an earlier release; since all such lockers are gone (they cannot
247 * survive through pg_upgrade), such tuples can safely be considered not
248 * locked.
249 *
250 * We must not resolve such multixacts locally, because the result would be
251 * bogus, regardless of where they stand with respect to the current valid
252 * multixact range.
253 */
254static inline bool
256{
257 return
258 (infomask & HEAP_XMAX_IS_MULTI) != 0 &&
259 (infomask & HEAP_XMAX_LOCK_ONLY) != 0 &&
260 (infomask & (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)) == 0;
261}
262
264 * Use these to test whether a particular lock is applied to a tuple
265 */
266static inline bool
268{
269 return (infomask & HEAP_LOCK_MASK) == HEAP_XMAX_SHR_LOCK;
270}
271
272static inline bool
274{
275 return (infomask & HEAP_LOCK_MASK) == HEAP_XMAX_EXCL_LOCK;
276}
277
278static inline bool
280{
281 return (infomask & HEAP_LOCK_MASK) == HEAP_XMAX_KEYSHR_LOCK;
282}
283
284/* turn these all off when Xmax is to change */
285#define HEAP_XMAX_BITS (HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID | \
286 HEAP_XMAX_IS_MULTI | HEAP_LOCK_MASK | HEAP_XMAX_LOCK_ONLY)
288/*
289 * information stored in t_infomask2:
290 */
291#define HEAP_NATTS_MASK 0x07FF /* 11 bits for number of attributes */
292/* bits 0x1800 are available */
293#define HEAP_KEYS_UPDATED 0x2000 /* tuple was updated and key cols
294 * modified, or tuple deleted */
295#define HEAP_HOT_UPDATED 0x4000 /* tuple was HOT-updated */
296#define HEAP_ONLY_TUPLE 0x8000 /* this is heap-only tuple */
297
298#define HEAP2_XACT_MASK 0xE000 /* visibility-related bits */
299
300/*
301 * HEAP_TUPLE_HAS_MATCH is a temporary flag used during hash joins. It is
302 * only used in tuples that are in the hash table, and those don't need
303 * any visibility information, so we can overlay it on a visibility flag
304 * instead of using up a dedicated bit.
305 */
306#define HEAP_TUPLE_HAS_MATCH HEAP_ONLY_TUPLE /* tuple has a join match */
307
308/*
309 * HeapTupleHeader accessor functions
310 */
311
312static bool HeapTupleHeaderXminFrozen(const HeapTupleHeaderData *tup);
313
314/*
315 * HeapTupleHeaderGetRawXmin returns the "raw" xmin field, which is the xid
316 * originally used to insert the tuple. However, the tuple might actually
317 * be frozen (via HeapTupleHeaderSetXminFrozen) in which case the tuple's xmin
318 * is visible to every snapshot. Prior to PostgreSQL 9.4, we actually changed
319 * the xmin to FrozenTransactionId, and that value may still be encountered
320 * on disk.
321 */
322static inline TransactionId
325 return tup->t_choice.t_heap.t_xmin;
326}
327
328static inline TransactionId
330{
333}
334
335static inline void
338 tup->t_choice.t_heap.t_xmin = xid;
339}
340
341static inline bool
344 return (tup->t_infomask & HEAP_XMIN_COMMITTED) != 0;
345}
346
347static inline bool
349{
350 return (tup->t_infomask & (HEAP_XMIN_COMMITTED | HEAP_XMIN_INVALID)) ==
352}
353
354static inline bool
358}
359
360static inline void
362{
365}
366
367static inline void
369{
372}
373
374static inline void
376{
379}
380
381static inline TransactionId
384 return tup->t_choice.t_heap.t_xmax;
385}
386
387static inline void
389{
390 tup->t_choice.t_heap.t_xmax = xid;
391}
392
393#ifndef FRONTEND
394/*
395 * HeapTupleHeaderGetRawXmax gets you the raw Xmax field. To find out the Xid
396 * that updated a tuple, you might need to resolve the MultiXactId if certain
397 * bits are set. HeapTupleHeaderGetUpdateXid checks those bits and takes care
398 * to resolve the MultiXactId if necessary. This might involve multixact I/O,
399 * so it should only be used if absolutely necessary.
400 */
401static inline TransactionId
403{
404 if (!((tup)->t_infomask & HEAP_XMAX_INVALID) &&
405 ((tup)->t_infomask & HEAP_XMAX_IS_MULTI) &&
406 !((tup)->t_infomask & HEAP_XMAX_LOCK_ONLY))
407 return HeapTupleGetUpdateXid(tup);
408 else
409 return HeapTupleHeaderGetRawXmax(tup);
410}
411#endif /* FRONTEND */
412
413/*
414 * HeapTupleHeaderGetRawCommandId will give you what's in the header whether
415 * it is useful or not. Most code should use HeapTupleHeaderGetCmin or
416 * HeapTupleHeaderGetCmax instead, but note that those Assert that you can
417 * get a legitimate result, ie you are in the originating transaction!
418 */
419static inline CommandId
421{
423}
424
425/* SetCmin is reasonably simple since we never need a combo CID */
426static inline void
428{
429 Assert(!(tup->t_infomask & HEAP_MOVED));
430 tup->t_choice.t_heap.t_field3.t_cid = cid;
431 tup->t_infomask &= ~HEAP_COMBOCID;
432}
433
434/* SetCmax must be used after HeapTupleHeaderAdjustCmax; see combocid.c */
435static inline void
437{
438 Assert(!((tup)->t_infomask & HEAP_MOVED));
439 tup->t_choice.t_heap.t_field3.t_cid = cid;
440 if (iscombo)
442 else
443 tup->t_infomask &= ~HEAP_COMBOCID;
444}
445
446static inline TransactionId
448{
449 if (tup->t_infomask & HEAP_MOVED)
450 return tup->t_choice.t_heap.t_field3.t_xvac;
451 else
453}
454
455static inline void
459 tup->t_choice.t_heap.t_field3.t_xvac = xid;
460}
463 "invalid speculative token constant");
464
465static inline bool
469}
470
471static inline BlockNumber
473{
475 return ItemPointerGetBlockNumber(&tup->t_ctid);
476}
477
478static inline void
482}
483
484static inline bool
488}
489
490static inline void
494}
495
496static inline uint32
499 return VARSIZE(tup);
500}
501
502static inline void
505 SET_VARSIZE(tup, len);
506}
507
508static inline Oid
511 return tup->t_choice.t_datum.datum_typeid;
512}
513
514static inline void
517 tup->t_choice.t_datum.datum_typeid = datum_typeid;
518}
519
520static inline int32
523 return tup->t_choice.t_datum.datum_typmod;
524}
525
526static inline void
528{
529 tup->t_choice.t_datum.datum_typmod = typmod;
530}
531
532/*
533 * Note that we stop considering a tuple HOT-updated as soon as it is known
534 * aborted or the would-be updating transaction is known aborted. For best
535 * efficiency, check tuple visibility before using this function, so that the
536 * INVALID bits will be as up to date as possible.
537 */
538static inline bool
540{
541 return
542 (tup->t_infomask2 & HEAP_HOT_UPDATED) != 0 &&
545}
546
547static inline void
551}
552
553static inline void
556 tup->t_infomask2 &= ~HEAP_HOT_UPDATED;
557}
558
559static inline bool
562 return (tup->t_infomask2 & HEAP_ONLY_TUPLE) != 0;
563}
564
565static inline void
569}
570
571static inline void
573{
574 tup->t_infomask2 &= ~HEAP_ONLY_TUPLE;
575}
576
578 * These are used with both HeapTuple and MinimalTuple, so they must be
579 * macros.
580 */
581
582#define HeapTupleHeaderGetNatts(tup) \
583 ((tup)->t_infomask2 & HEAP_NATTS_MASK)
584
585#define HeapTupleHeaderSetNatts(tup, natts) \
586( \
587 (tup)->t_infomask2 = ((tup)->t_infomask2 & ~HEAP_NATTS_MASK) | (natts) \
588)
589
590#define HeapTupleHeaderHasExternal(tup) \
591 (((tup)->t_infomask & HEAP_HASEXTERNAL) != 0)
592
593
595 * BITMAPLEN(NATTS) -
596 * Computes size of null bitmap given number of data columns.
597 */
598static inline int
599BITMAPLEN(int NATTS)
600{
601 return (NATTS + 7) / 8;
602}
603
604/*
605 * MaxHeapTupleSize is the maximum allowed size of a heap tuple, including
606 * header and MAXALIGN alignment padding. Basically it's BLCKSZ minus the
607 * other stuff that has to be on a disk page. Since heap pages use no
608 * "special space", there's no deduction for that.
609 *
610 * NOTE: we allow for the ItemId that must point to the tuple, ensuring that
611 * an otherwise-empty page can indeed hold a tuple of this size. Because
612 * ItemIds and tuples have different alignment requirements, don't assume that
613 * you can, say, fit 2 tuples of size MaxHeapTupleSize/2 on the same page.
614 */
615#define MaxHeapTupleSize (BLCKSZ - MAXALIGN(SizeOfPageHeaderData + sizeof(ItemIdData)))
616#define MinHeapTupleSize MAXALIGN(SizeofHeapTupleHeader)
617
618/*
619 * MaxHeapTuplesPerPage is an upper bound on the number of tuples that can
620 * fit on one heap page. (Note that indexes could have more, because they
621 * use a smaller tuple header.) We arrive at the divisor because each tuple
622 * must be maxaligned, and it must have an associated line pointer.
623 *
624 * Note: with HOT, there could theoretically be more line pointers (not actual
625 * tuples) than this on a heap page. However we constrain the number of line
626 * pointers to this anyway, to avoid excessive line-pointer bloat and not
627 * require increases in the size of work arrays.
628 */
629#define MaxHeapTuplesPerPage \
630 ((int) ((BLCKSZ - SizeOfPageHeaderData) / \
631 (MAXALIGN(SizeofHeapTupleHeader) + sizeof(ItemIdData))))
632
633/*
634 * MaxAttrSize is a somewhat arbitrary upper limit on the declared size of
635 * data fields of char(n) and similar types. It need not have anything
636 * directly to do with the *actual* upper limit of varlena values, which
637 * is currently 1Gb (see TOAST structures in postgres.h). I've set it
638 * at 10Mb which seems like a reasonable number --- tgl 8/6/00.
639 */
640#define MaxAttrSize (10 * 1024 * 1024)
641
642
643/*
644 * MinimalTuple is an alternative representation that is used for transient
645 * tuples inside the executor, in places where transaction status information
646 * is not required, the tuple rowtype is known, and shaving off a few bytes
647 * is worthwhile because we need to store many tuples. The representation
648 * is chosen so that tuple access routines can work with either full or
649 * minimal tuples via a HeapTupleData pointer structure. The access routines
650 * see no difference, except that they must not access the transaction status
651 * or t_ctid fields because those aren't there.
652 *
653 * For the most part, MinimalTuples should be accessed via TupleTableSlot
654 * routines. These routines will prevent access to the "system columns"
655 * and thereby prevent accidental use of the nonexistent fields.
656 *
657 * MinimalTupleData contains a length word, some padding, and fields matching
658 * HeapTupleHeaderData beginning with t_infomask2. The padding is chosen so
659 * that offsetof(t_infomask2) is the same modulo MAXIMUM_ALIGNOF in both
660 * structs. This makes data alignment rules equivalent in both cases.
661 *
662 * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is
663 * set to point MINIMAL_TUPLE_OFFSET bytes before the actual start of the
664 * minimal tuple --- that is, where a full tuple matching the minimal tuple's
665 * data would start. This trick is what makes the structs seem equivalent.
666 *
667 * Note that t_hoff is computed the same as in a full tuple, hence it includes
668 * the MINIMAL_TUPLE_OFFSET distance. t_len does not include that, however.
670 * MINIMAL_TUPLE_DATA_OFFSET is the offset to the first useful (non-pad) data
671 * other than the length word. tuplesort.c and tuplestore.c use this to avoid
672 * writing the padding to disk.
673 */
674#define MINIMAL_TUPLE_OFFSET \
675 ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF)
676#define MINIMAL_TUPLE_PADDING \
677 ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF)
678#define MINIMAL_TUPLE_DATA_OFFSET \
679 offsetof(MinimalTupleData, t_infomask2)
681struct MinimalTupleData
682{
683 uint32 t_len; /* actual length of minimal tuple */
687 /* Fields below here must match HeapTupleHeaderData! */
689 uint16 t_infomask2; /* number of attributes + various flags */
690
691 uint16 t_infomask; /* various flag bits, see below */
693 uint8 t_hoff; /* sizeof header incl. bitmap, padding */
694
695 /* ^ - 23 bytes - ^ */
696
697 bits8 t_bits[FLEXIBLE_ARRAY_MEMBER]; /* bitmap of NULLs */
698
699 /* MORE DATA FOLLOWS AT END OF STRUCT */
700};
701
702/* typedef appears in htup.h */
703
704#define SizeofMinimalTupleHeader offsetof(MinimalTupleData, t_bits)
705
707 * MinimalTuple accessor functions
708 */
709
710static inline bool
713 return (tup->t_infomask2 & HEAP_TUPLE_HAS_MATCH) != 0;
714}
715
716static inline void
720}
721
722static inline void
724{
725 tup->t_infomask2 &= ~HEAP_TUPLE_HAS_MATCH;
726}
727
729/*
730 * GETSTRUCT - given a HeapTuple pointer, return address of the user data
731 */
732static inline void *
733GETSTRUCT(const HeapTupleData *tuple)
734{
735 return ((char *) (tuple->t_data) + tuple->t_data->t_hoff);
736}
737
739 * Accessor functions to be used with HeapTuple pointers.
740 */
741
742static inline bool
745 return (tuple->t_data->t_infomask & HEAP_HASNULL) != 0;
746}
747
748static inline bool
751 return !HeapTupleHasNulls(tuple);
752}
753
754static inline bool
757 return (tuple->t_data->t_infomask & HEAP_HASVARWIDTH) != 0;
758}
759
760static inline bool
763 return !HeapTupleHasVarWidth(tuple);
764}
765
766static inline bool
769 return (tuple->t_data->t_infomask & HEAP_HASEXTERNAL) != 0;
770}
771
772static inline bool
775 return HeapTupleHeaderIsHotUpdated(tuple->t_data);
776}
777
778static inline void
782}
783
784static inline void
788}
789
790static inline bool
793 return HeapTupleHeaderIsHeapOnly(tuple->t_data);
794}
795
796static inline void
800}
801
802static inline void
804{
806}
807
808/* prototypes for functions in common/heaptuple.c */
809extern Size heap_compute_data_size(TupleDesc tupleDesc,
810 const Datum *values, const bool *isnull);
811extern void heap_fill_tuple(TupleDesc tupleDesc,
812 const Datum *values, const bool *isnull,
813 char *data, Size data_size,
814 uint16 *infomask, bits8 *bit);
815extern bool heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc);
816extern Datum nocachegetattr(HeapTuple tup, int attnum,
817 TupleDesc tupleDesc);
818extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
819 bool *isnull);
820extern Datum getmissingattr(TupleDesc tupleDesc,
821 int attnum, bool *isnull);
824extern Datum heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc);
825extern HeapTuple heap_form_tuple(TupleDesc tupleDescriptor,
826 const Datum *values, const bool *isnull);
828 TupleDesc tupleDesc,
829 const Datum *replValues,
830 const bool *replIsnull,
831 const bool *doReplace);
833 TupleDesc tupleDesc,
834 int nCols,
835 const int *replCols,
836 const Datum *replValues,
837 const bool *replIsnull);
838extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
839 Datum *values, bool *isnull);
840extern void heap_freetuple(HeapTuple htup);
841extern MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor,
842 const Datum *values, const bool *isnull);
843extern void heap_free_minimal_tuple(MinimalTuple mtup);
847extern size_t varsize_any(void *p);
848extern HeapTuple heap_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
849extern MinimalTuple minimal_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
850
851#ifndef FRONTEND
852/*
853 * fastgetattr
854 * Fetch a user attribute's value as a Datum (might be either a
855 * value, or a pointer into the data area of the tuple).
856 *
857 * This must not be used when a system attribute might be requested.
858 * Furthermore, the passed attnum MUST be valid. Use heap_getattr()
859 * instead, if in doubt.
861 * This gets called many times, so we macro the cacheable and NULL
862 * lookups, and call nocachegetattr() for the rest.
863 */
864static inline Datum
865fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
866{
867 Assert(attnum > 0);
868
869 *isnull = false;
870 if (HeapTupleNoNulls(tup))
871 {
872 CompactAttribute *att;
873
874 att = TupleDescCompactAttr(tupleDesc, attnum - 1);
875 if (att->attcacheoff >= 0)
876 return fetchatt(att, (char *) tup->t_data + tup->t_data->t_hoff +
877 att->attcacheoff);
878 else
879 return nocachegetattr(tup, attnum, tupleDesc);
880 }
881 else
882 {
883 if (att_isnull(attnum - 1, tup->t_data->t_bits))
884 {
885 *isnull = true;
886 return (Datum) NULL;
887 }
888 else
889 return nocachegetattr(tup, attnum, tupleDesc);
890 }
891}
892
893/*
894 * heap_getattr
895 * Extract an attribute of a heap tuple and return it as a Datum.
896 * This works for either system or user attributes. The given attnum
897 * is properly range-checked.
898 *
899 * If the field in question has a NULL value, we return a zero Datum
900 * and set *isnull == true. Otherwise, we set *isnull == false.
901 *
902 * <tup> is the pointer to the heap tuple. <attnum> is the attribute
903 * number of the column (field) caller wants. <tupleDesc> is a
904 * pointer to the structure describing the row and all its fields.
905 *
906 */
907static inline Datum
908heap_getattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
909{
910 if (attnum > 0)
911 {
912 if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
913 return getmissingattr(tupleDesc, attnum, isnull);
914 else
915 return fastgetattr(tup, attnum, tupleDesc, isnull);
916 }
917 else
918 return heap_getsysattr(tup, attnum, tupleDesc, isnull);
919}
920#endif /* FRONTEND */
921
922#endif /* HTUP_DETAILS_H */
uint32 BlockNumber
Definition: block.h:31
static Datum values[MAXATTR]
Definition: bootstrap.c:151
uint8_t uint8
Definition: c.h:486
#define Assert(condition)
Definition: c.h:815
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:420
int16_t int16
Definition: c.h:483
uint8 bits8
Definition: c.h:495
int32_t int32
Definition: c.h:484
uint16_t uint16
Definition: c.h:487
uint32_t uint32
Definition: c.h:488
uint32 CommandId
Definition: c.h:623
uint32 TransactionId
Definition: c.h:609
size_t Size
Definition: c.h:562
TransactionId HeapTupleGetUpdateXid(const HeapTupleHeaderData *tup)
Definition: heapam.c:7487
#define HEAP_HASVARWIDTH
Definition: htup_details.h:191
Size heap_compute_data_size(TupleDesc tupleDesc, const Datum *values, const bool *isnull)
Definition: heaptuple.c:219
static bool HEAP_XMAX_IS_SHR_LOCKED(int16 infomask)
Definition: htup_details.h:263
#define HEAP_XMAX_SHR_LOCK
Definition: htup_details.h:200
static bool HeapTupleIsHotUpdated(const HeapTupleData *tuple)
Definition: htup_details.h:768
#define HEAP_XMIN_FROZEN
Definition: htup_details.h:206
static Datum heap_getattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
Definition: htup_details.h:903
static bool HeapTupleHeaderXminFrozen(const HeapTupleHeaderData *tup)
Definition: htup_details.h:350
struct HeapTupleFields HeapTupleFields
static void HeapTupleHeaderClearHeapOnly(HeapTupleHeaderData *tup)
Definition: htup_details.h:567
#define HEAP_XMIN_COMMITTED
Definition: htup_details.h:204
#define HeapTupleHeaderGetNatts(tup)
Definition: htup_details.h:577
static void HeapTupleHeaderSetXminFrozen(HeapTupleHeaderData *tup)
Definition: htup_details.h:370
HeapTuple heap_modify_tuple(HeapTuple tuple, TupleDesc tupleDesc, const Datum *replValues, const bool *replIsnull, const bool *doReplace)
Definition: heaptuple.c:1210
void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest)
Definition: heaptuple.c:804
HeapTuple heap_copytuple(HeapTuple tuple)
Definition: heaptuple.c:778
static void HeapTupleHeaderSetTypMod(HeapTupleHeaderData *tup, int32 typmod)
Definition: htup_details.h:522
size_t varsize_any(void *p)
Definition: heaptuple.c:1595
#define HEAP_HOT_UPDATED
Definition: htup_details.h:290
MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup)
Definition: heaptuple.c:1577
static bool HeapTupleHasNulls(const HeapTupleData *tuple)
Definition: htup_details.h:738
static void HeapTupleHeaderSetSpeculativeToken(HeapTupleHeaderData *tup, BlockNumber token)
Definition: htup_details.h:474
Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
Definition: heaptuple.c:725
static void HeapTupleHeaderSetMatch(MinimalTupleData *tup)
Definition: htup_details.h:712
#define HEAP_HASNULL
Definition: htup_details.h:190
static bool HEAP_XMAX_IS_LOCKED_ONLY(uint16 infomask)
Definition: htup_details.h:226
static int BITMAPLEN(int NATTS)
Definition: htup_details.h:594
static bool HeapTupleHeaderXminInvalid(const HeapTupleHeaderData *tup)
Definition: htup_details.h:343
static void HeapTupleClearHotUpdated(const HeapTupleData *tuple)
Definition: htup_details.h:780
static int32 HeapTupleHeaderGetTypMod(const HeapTupleHeaderData *tup)
Definition: htup_details.h:516
static bool HeapTupleHasExternal(const HeapTupleData *tuple)
Definition: htup_details.h:762
static TransactionId HeapTupleHeaderGetXvac(const HeapTupleHeaderData *tup)
Definition: htup_details.h:442
static void HeapTupleHeaderSetXminInvalid(HeapTupleHeaderData *tup)
Definition: htup_details.h:363
static bool HeapTupleAllFixed(const HeapTupleData *tuple)
Definition: htup_details.h:756
static void HeapTupleHeaderSetCmax(HeapTupleHeaderData *tup, CommandId cid, bool iscombo)
Definition: htup_details.h:431
MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: heaptuple.c:1453
static void HeapTupleHeaderSetTypeId(HeapTupleHeaderData *tup, Oid datum_typeid)
Definition: htup_details.h:510
#define HEAP_XMAX_LOCK_ONLY
Definition: htup_details.h:197
static void HeapTupleHeaderClearHotUpdated(HeapTupleHeaderData *tup)
Definition: htup_details.h:549
static void HeapTupleHeaderSetCmin(HeapTupleHeaderData *tup, CommandId cid)
Definition: htup_details.h:422
#define HEAP_LOCK_MASK
Definition: htup_details.h:202
static CommandId HeapTupleHeaderGetRawCommandId(const HeapTupleHeaderData *tup)
Definition: htup_details.h:415
HeapTuple heap_modify_tuple_by_cols(HeapTuple tuple, TupleDesc tupleDesc, int nCols, const int *replCols, const Datum *replValues, const bool *replIsnull)
Definition: heaptuple.c:1278
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: heaptuple.c:1117
static TransactionId HeapTupleHeaderGetRawXmax(const HeapTupleHeaderData *tup)
Definition: htup_details.h:377
static bool HeapTupleHeaderIsHeapOnly(const HeapTupleHeaderData *tup)
Definition: htup_details.h:555
static void HeapTupleHeaderClearMatch(MinimalTupleData *tup)
Definition: htup_details.h:718
void heap_free_minimal_tuple(MinimalTuple mtup)
Definition: heaptuple.c:1524
static bool HeapTupleIsHeapOnly(const HeapTupleData *tuple)
Definition: htup_details.h:786
#define HEAP_MOVED
Definition: htup_details.h:213
bool heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc)
Definition: heaptuple.c:456
Datum nocachegetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc)
Definition: heaptuple.c:521
static void HeapTupleSetHeapOnly(const HeapTupleData *tuple)
Definition: htup_details.h:792
static bool HeapTupleNoNulls(const HeapTupleData *tuple)
Definition: htup_details.h:744
static bool HEAP_XMAX_IS_KEYSHR_LOCKED(int16 infomask)
Definition: htup_details.h:275
static void HeapTupleHeaderSetXminCommitted(HeapTupleHeaderData *tup)
Definition: htup_details.h:356
#define HEAP_TUPLE_HAS_MATCH
Definition: htup_details.h:301
Datum getmissingattr(TupleDesc tupleDesc, int attnum, bool *isnull)
Definition: heaptuple.c:151
static void HeapTupleHeaderSetHeapOnly(HeapTupleHeaderData *tup)
Definition: htup_details.h:561
#define HEAP_XMAX_IS_MULTI
Definition: htup_details.h:209
HeapTuple heap_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc)
Definition: heaptuple.c:1066
static bool HeapTupleHeaderHasMatch(const MinimalTupleData *tup)
Definition: htup_details.h:706
static TransactionId HeapTupleHeaderGetXmin(const HeapTupleHeaderData *tup)
Definition: htup_details.h:324
#define HEAP_COMBOCID
Definition: htup_details.h:195
void heap_fill_tuple(TupleDesc tupleDesc, const Datum *values, const bool *isnull, char *data, Size data_size, uint16 *infomask, bits8 *bit)
Definition: heaptuple.c:401
static void HeapTupleHeaderSetXvac(HeapTupleHeaderData *tup, TransactionId xid)
Definition: htup_details.h:451
struct DatumTupleFields DatumTupleFields
void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc, Datum *values, bool *isnull)
Definition: heaptuple.c:1346
#define HEAP_XMIN_INVALID
Definition: htup_details.h:205
#define HEAP_HASEXTERNAL
Definition: htup_details.h:192
static bool HeapTupleHeaderIndicatesMovedPartitions(const HeapTupleHeaderData *tup)
Definition: htup_details.h:480
static void HeapTupleSetHotUpdated(const HeapTupleData *tuple)
Definition: htup_details.h:774
MinimalTuple heap_copy_minimal_tuple(MinimalTuple mtup)
Definition: heaptuple.c:1536
#define HEAP_XMAX_EXCL_LOCK
Definition: htup_details.h:196
static BlockNumber HeapTupleHeaderGetSpeculativeToken(const HeapTupleHeaderData *tup)
Definition: htup_details.h:467
static bool HeapTupleHeaderIsHotUpdated(const HeapTupleHeaderData *tup)
Definition: htup_details.h:534
#define HEAP_XMAX_INVALID
Definition: htup_details.h:208
static void HeapTupleHeaderSetDatumLength(HeapTupleHeaderData *tup, uint32 len)
Definition: htup_details.h:498
#define MINIMAL_TUPLE_PADDING
Definition: htup_details.h:671
static TransactionId HeapTupleHeaderGetRawXmin(const HeapTupleHeaderData *tup)
Definition: htup_details.h:318
static uint32 HeapTupleHeaderGetDatumLength(const HeapTupleHeaderData *tup)
Definition: htup_details.h:492
static void * GETSTRUCT(const HeapTupleData *tuple)
Definition: htup_details.h:728
static void HeapTupleClearHeapOnly(const HeapTupleData *tuple)
Definition: htup_details.h:798
Datum heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc)
Definition: heaptuple.c:1081
static bool HeapTupleHeaderIsSpeculative(const HeapTupleHeaderData *tup)
Definition: htup_details.h:461
static TransactionId HeapTupleHeaderGetUpdateXid(const HeapTupleHeaderData *tup)
Definition: htup_details.h:397
StaticAssertDecl(MaxOffsetNumber< SpecTokenOffsetNumber, "invalid speculative token constant")
static void HeapTupleHeaderSetXmin(HeapTupleHeaderData *tup, TransactionId xid)
Definition: htup_details.h:331
static bool HEAP_LOCKED_UPGRADED(uint16 infomask)
Definition: htup_details.h:251
#define HEAP_XMAX_KEYSHR_LOCK
Definition: htup_details.h:194
static bool HEAP_XMAX_IS_EXCL_LOCKED(int16 infomask)
Definition: htup_details.h:269
static Oid HeapTupleHeaderGetTypeId(const HeapTupleHeaderData *tup)
Definition: htup_details.h:504
HeapTuple heap_tuple_from_minimal_tuple(MinimalTuple mtup)
Definition: heaptuple.c:1555
MinimalTuple minimal_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc)
Definition: heaptuple.c:1054
static void HeapTupleHeaderSetMovedPartitions(HeapTupleHeaderData *tup)
Definition: htup_details.h:486
static Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
Definition: htup_details.h:860
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1435
static void HeapTupleHeaderSetXmax(HeapTupleHeaderData *tup, TransactionId xid)
Definition: htup_details.h:383
static bool HeapTupleHasVarWidth(const HeapTupleData *tuple)
Definition: htup_details.h:750
static bool HeapTupleHeaderXminCommitted(const HeapTupleHeaderData *tup)
Definition: htup_details.h:337
#define HEAP_ONLY_TUPLE
Definition: htup_details.h:291
static void HeapTupleHeaderSetHotUpdated(HeapTupleHeaderData *tup)
Definition: htup_details.h:543
#define token
Definition: indent_globs.h:126
static void ItemPointerSet(ItemPointerData *pointer, BlockNumber blockNumber, OffsetNumber offNum)
Definition: itemptr.h:135
static bool ItemPointerIndicatesMovedPartitions(const ItemPointerData *pointer)
Definition: itemptr.h:197
static void ItemPointerSetMovedPartitions(ItemPointerData *pointer)
Definition: itemptr.h:210
static OffsetNumber ItemPointerGetOffsetNumberNoCheck(const ItemPointerData *pointer)
Definition: itemptr.h:114
static BlockNumber ItemPointerGetBlockNumber(const ItemPointerData *pointer)
Definition: itemptr.h:103
#define SpecTokenOffsetNumber
Definition: itemptr.h:63
#define MaxOffsetNumber
Definition: off.h:28
int16 attnum
Definition: pg_attribute.h:74
const void size_t len
const void * data
uintptr_t Datum
Definition: postgres.h:69
unsigned int Oid
Definition: postgres_ext.h:32
int32 attcacheoff
Definition: tupdesc.h:70
HeapTupleHeader t_data
Definition: htup.h:68
union HeapTupleFields::@46 t_field3
TransactionId t_xmin
Definition: htup_details.h:124
CommandId t_cid
Definition: htup_details.h:129
TransactionId t_xmax
Definition: htup_details.h:125
TransactionId t_xvac
Definition: htup_details.h:130
union HeapTupleHeaderData::@47 t_choice
ItemPointerData t_ctid
Definition: htup_details.h:161
bits8 t_bits[FLEXIBLE_ARRAY_MEMBER]
Definition: htup_details.h:178
HeapTupleFields t_heap
Definition: htup_details.h:157
DatumTupleFields t_datum
Definition: htup_details.h:158
char mt_padding[MINIMAL_TUPLE_PADDING]
Definition: htup_details.h:680
bits8 t_bits[FLEXIBLE_ARRAY_MEMBER]
Definition: htup_details.h:692
#define FrozenTransactionId
Definition: transam.h:33
#define InvalidTransactionId
Definition: transam.h:31
static CompactAttribute * TupleDescCompactAttr(TupleDesc tupdesc, int i)
Definition: tupdesc.h:169
static bool att_isnull(int ATT, const bits8 *BITS)
Definition: tupmacs.h:26
#define fetchatt(A, T)
Definition: tupmacs.h:47
#define SET_VARSIZE(PTR, len)
Definition: varatt.h:305
#define VARSIZE(PTR)
Definition: varatt.h:279
Datum bit(PG_FUNCTION_ARGS)
Definition: varbit.c:391