* POSTGRES heap tuple definitions.
*
*
- * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/access/htup.h,v 1.96 2007/11/15 21:14:42 momjian Exp $
+ * src/include/access/htup.h
*
*-------------------------------------------------------------------------
*/
#ifndef HTUP_H
#define HTUP_H
+#include "access/tupdesc.h"
+#include "access/tupmacs.h"
#include "storage/itemptr.h"
#include "storage/relfilenode.h"
* transaction respectively. If a tuple is inserted and deleted in the same
* transaction, we store a "combo" command id that can be mapped to the real
* cmin and cmax, but only by use of local state within the originating
- * backend. See combocid.c for more details. Meanwhile, Xvac is only set
- * by VACUUM FULL, which does not have any command sub-structure and so does
- * not need either Cmin or Cmax. (This requires that VACUUM FULL never try
- * to move a tuple whose Cmin or Cmax is still interesting, ie, an insert-
- * in-progress or delete-in-progress tuple.)
+ * backend. See combocid.c for more details. Meanwhile, Xvac is only set by
+ * old-style VACUUM FULL, which does not have any command sub-structure and so
+ * does not need either Cmin or Cmax. (This requires that old-style VACUUM
+ * FULL never try to move a tuple whose Cmin or Cmax is still interesting,
+ * ie, an insert-in-progress or delete-in-progress tuple.)
*
* A word about t_ctid: whenever a new tuple is stored on disk, its t_ctid
* is initialized with its own TID (location). If the tuple is ever updated,
union
{
CommandId t_cid; /* inserting or deleting command ID, or both */
- TransactionId t_xvac; /* VACUUM FULL xact ID */
+ TransactionId t_xvac; /* old-style VACUUM FULL xact ID */
} t_field3;
} HeapTupleFields;
#define HEAP_XMAX_INVALID 0x0800 /* t_xmax invalid/aborted */
#define HEAP_XMAX_IS_MULTI 0x1000 /* t_xmax is a MultiXactId */
#define HEAP_UPDATED 0x2000 /* this is UPDATEd version of row */
-#define HEAP_MOVED_OFF 0x4000 /* moved to another place by VACUUM
- * FULL */
-#define HEAP_MOVED_IN 0x8000 /* moved from another place by VACUUM
- * FULL */
+#define HEAP_MOVED_OFF 0x4000 /* moved to another place by pre-9.0
+ * VACUUM FULL; kept for binary
+ * upgrade support */
+#define HEAP_MOVED_IN 0x8000 /* moved from another place by pre-9.0
+ * VACUUM FULL; kept for binary
+ * upgrade support */
#define HEAP_MOVED (HEAP_MOVED_OFF | HEAP_MOVED_IN)
#define HEAP_XACT_MASK 0xFFE0 /* visibility-related bits */
* other stuff that has to be on a disk page. Since heap pages use no
* "special space", there's no deduction for that.
*
- * NOTE: we do not need to count an ItemId for the tuple because
- * sizeof(PageHeaderData) includes the first ItemId on the page. But beware
- * of assuming that, say, you can fit 2 tuples of size MaxHeapTupleSize/2
- * on the same page.
+ * NOTE: we allow for the ItemId that must point to the tuple, ensuring that
+ * an otherwise-empty page can indeed hold a tuple of this size. Because
+ * ItemIds and tuples have different alignment requirements, don't assume that
+ * you can, say, fit 2 tuples of size MaxHeapTupleSize/2 on the same page.
*/
-#define MaxHeapTupleSize (BLCKSZ - MAXALIGN(sizeof(PageHeaderData)))
+#define MaxHeapTupleSize (BLCKSZ - MAXALIGN(SizeOfPageHeaderData + sizeof(ItemIdData)))
/*
* MaxHeapTuplesPerPage is an upper bound on the number of tuples that can
* require increases in the size of work arrays.
*/
#define MaxHeapTuplesPerPage \
- ((int) ((BLCKSZ - offsetof(PageHeaderData, pd_linp)) / \
+ ((int) ((BLCKSZ - SizeOfPageHeaderData) / \
(MAXALIGN(offsetof(HeapTupleHeaderData, t_bits)) + sizeof(ItemIdData))))
/*
#define MaxAttrSize (10 * 1024 * 1024)
-/*
- * Attribute numbers for the system-defined attributes
- */
-#define SelfItemPointerAttributeNumber (-1)
-#define ObjectIdAttributeNumber (-2)
-#define MinTransactionIdAttributeNumber (-3)
-#define MinCommandIdAttributeNumber (-4)
-#define MaxTransactionIdAttributeNumber (-5)
-#define MaxCommandIdAttributeNumber (-6)
-#define TableOidAttributeNumber (-7)
-#define FirstLowInvalidHeapAttributeNumber (-8)
-
-
/*
* MinimalTuple is an alternative representation that is used for transient
* tuples inside the executor, in places where transaction status information
*
* Note that t_hoff is computed the same as in a full tuple, hence it includes
* the MINIMAL_TUPLE_OFFSET distance. t_len does not include that, however.
+ *
+ * MINIMAL_TUPLE_DATA_OFFSET is the offset to the first useful (non-pad) data
+ * other than the length word. tuplesort.c and tuplestore.c use this to avoid
+ * writing the padding to disk.
*/
#define MINIMAL_TUPLE_OFFSET \
((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF)
#define MINIMAL_TUPLE_PADDING \
((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF)
+#define MINIMAL_TUPLE_DATA_OFFSET \
+ offsetof(MinimalTupleData, t_infomask2)
typedef struct MinimalTupleData
{
#define XLOG_HEAP_INSERT 0x00
#define XLOG_HEAP_DELETE 0x10
#define XLOG_HEAP_UPDATE 0x20
-#define XLOG_HEAP_MOVE 0x30
+/* 0x030 is free, was XLOG_HEAP_MOVE */
#define XLOG_HEAP_HOT_UPDATE 0x40
#define XLOG_HEAP_NEWPAGE 0x50
#define XLOG_HEAP_LOCK 0x60
*/
#define XLOG_HEAP2_FREEZE 0x00
#define XLOG_HEAP2_CLEAN 0x10
-#define XLOG_HEAP2_CLEAN_MOVE 0x20
+/* 0x20 is free, was XLOG_HEAP2_CLEAN_MOVE */
+#define XLOG_HEAP2_CLEANUP_INFO 0x30
/*
* All what we need to find changed tuple
typedef struct xl_heap_delete
{
xl_heaptid target; /* deleted tuple id */
+ bool all_visible_cleared; /* PD_ALL_VISIBLE was cleared */
} xl_heap_delete;
-#define SizeOfHeapDelete (offsetof(xl_heap_delete, target) + SizeOfHeapTid)
+#define SizeOfHeapDelete (offsetof(xl_heap_delete, all_visible_cleared) + sizeof(bool))
/*
* We don't store the whole fixed part (HeapTupleHeaderData) of an inserted
typedef struct xl_heap_insert
{
xl_heaptid target; /* inserted tuple id */
+ bool all_visible_cleared; /* PD_ALL_VISIBLE was cleared */
/* xl_heap_header & TUPLE DATA FOLLOWS AT END OF STRUCT */
} xl_heap_insert;
-#define SizeOfHeapInsert (offsetof(xl_heap_insert, target) + SizeOfHeapTid)
+#define SizeOfHeapInsert (offsetof(xl_heap_insert, all_visible_cleared) + sizeof(bool))
-/* This is what we need to know about update|move|hot_update */
+/* This is what we need to know about update|hot_update */
typedef struct xl_heap_update
{
xl_heaptid target; /* deleted tuple id */
ItemPointerData newtid; /* new inserted tuple id */
- /* NEW TUPLE xl_heap_header (PLUS xmax & xmin IF MOVE OP) */
- /* and TUPLE DATA FOLLOWS AT END OF STRUCT */
+ bool all_visible_cleared; /* PD_ALL_VISIBLE was cleared */
+ bool new_all_visible_cleared; /* same for the page of newtid */
+ /* NEW TUPLE xl_heap_header AND TUPLE DATA FOLLOWS AT END OF STRUCT */
} xl_heap_update;
-#define SizeOfHeapUpdate (offsetof(xl_heap_update, newtid) + SizeOfIptrData)
+#define SizeOfHeapUpdate (offsetof(xl_heap_update, new_all_visible_cleared) + sizeof(bool))
/*
* This is what we need to know about vacuum page cleanup/redirect
* The total number of OffsetNumbers is therefore 2*nredirected+ndead+nunused.
* Note that nunused is not explicitly stored, but may be found by reference
* to the total record length.
- *
- * If the opcode is CLEAN_MOVE instead of CLEAN, then each redirection pair
- * should be interpreted as physically moving the "to" item pointer to the
- * "from" slot, rather than placing a redirection item in the "from" slot.
- * The moved pointers should be replaced by LP_UNUSED items (there will not
- * be explicit entries in the "now-unused" list for this). Also, the
- * HEAP_ONLY bit in the moved tuples must be turned off.
*/
typedef struct xl_heap_clean
{
RelFileNode node;
BlockNumber block;
+ TransactionId latestRemovedXid;
uint16 nredirected;
uint16 ndead;
/* OFFSET NUMBERS FOLLOW */
#define SizeOfHeapClean (offsetof(xl_heap_clean, ndead) + sizeof(uint16))
+/*
+ * Cleanup_info is required in some cases during a lazy VACUUM.
+ * Used for reporting the results of HeapTupleHeaderAdvanceLatestRemovedXid()
+ * see vacuumlazy.c for full explanation
+ */
+typedef struct xl_heap_cleanup_info
+{
+ RelFileNode node;
+ TransactionId latestRemovedXid;
+} xl_heap_cleanup_info;
+
+#define SizeOfHeapCleanupInfo (sizeof(xl_heap_cleanup_info))
+
/* This is for replacing a page's contents in toto */
/* NB: this is used for indexes as well as heaps */
typedef struct xl_heap_newpage
{
RelFileNode node;
+ ForkNumber forknum;
BlockNumber blkno; /* location of new page */
/* entire page contents follow at end of record */
} xl_heap_newpage;
BlockNumber block;
TransactionId cutoff_xid;
/* TUPLE OFFSET NUMBERS FOLLOW AT THE END */
-} xl_heap_freeze;
+} xl_heap_freeze;
#define SizeOfHeapFreeze (offsetof(xl_heap_freeze, cutoff_xid) + sizeof(TransactionId))
+extern void HeapTupleHeaderAdvanceLatestRemovedXid(HeapTupleHeader tuple,
+ TransactionId *latestRemovedXid);
+
/* HeapTupleHeader functions implemented in utils/time/combocid.c */
extern CommandId HeapTupleHeaderGetCmin(HeapTupleHeader tup);
extern CommandId HeapTupleHeaderGetCmax(HeapTupleHeader tup);
CommandId *cmax,
bool *iscombo);
+/* ----------------
+ * fastgetattr
+ *
+ * Fetch a user attribute's value as a Datum (might be either a
+ * value, or a pointer into the data area of the tuple).
+ *
+ * This must not be used when a system attribute might be requested.
+ * Furthermore, the passed attnum MUST be valid. Use heap_getattr()
+ * instead, if in doubt.
+ *
+ * This gets called many times, so we macro the cacheable and NULL
+ * lookups, and call nocachegetattr() for the rest.
+ * ----------------
+ */
+
+#if !defined(DISABLE_COMPLEX_MACRO)
+
+#define fastgetattr(tup, attnum, tupleDesc, isnull) \
+( \
+ AssertMacro((attnum) > 0), \
+ (*(isnull) = false), \
+ HeapTupleNoNulls(tup) ? \
+ ( \
+ (tupleDesc)->attrs[(attnum)-1]->attcacheoff >= 0 ? \
+ ( \
+ fetchatt((tupleDesc)->attrs[(attnum)-1], \
+ (char *) (tup)->t_data + (tup)->t_data->t_hoff + \
+ (tupleDesc)->attrs[(attnum)-1]->attcacheoff) \
+ ) \
+ : \
+ nocachegetattr((tup), (attnum), (tupleDesc)) \
+ ) \
+ : \
+ ( \
+ att_isnull((attnum)-1, (tup)->t_data->t_bits) ? \
+ ( \
+ (*(isnull) = true), \
+ (Datum)NULL \
+ ) \
+ : \
+ ( \
+ nocachegetattr((tup), (attnum), (tupleDesc)) \
+ ) \
+ ) \
+)
+#else /* defined(DISABLE_COMPLEX_MACRO) */
+
+extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
+ bool *isnull);
+#endif /* defined(DISABLE_COMPLEX_MACRO) */
+
+
+/* ----------------
+ * heap_getattr
+ *
+ * Extract an attribute of a heap tuple and return it as a Datum.
+ * This works for either system or user attributes. The given attnum
+ * is properly range-checked.
+ *
+ * If the field in question has a NULL value, we return a zero Datum
+ * and set *isnull == true. Otherwise, we set *isnull == false.
+ *
+ * <tup> is the pointer to the heap tuple. <attnum> is the attribute
+ * number of the column (field) caller wants. <tupleDesc> is a
+ * pointer to the structure describing the row and all its fields.
+ * ----------------
+ */
+#define heap_getattr(tup, attnum, tupleDesc, isnull) \
+( \
+ AssertMacro((tup) != NULL), \
+ ( \
+ ((attnum) > 0) ? \
+ ( \
+ ((attnum) > (int) HeapTupleHeaderGetNatts((tup)->t_data)) ? \
+ ( \
+ (*(isnull) = true), \
+ (Datum)NULL \
+ ) \
+ : \
+ fastgetattr((tup), (attnum), (tupleDesc), (isnull)) \
+ ) \
+ : \
+ heap_getsysattr((tup), (attnum), (tupleDesc), (isnull)) \
+ ) \
+)
+
+/* prototypes for functions in common/heaptuple.c */
+extern Size heap_compute_data_size(TupleDesc tupleDesc,
+ Datum *values, bool *isnull);
+extern void heap_fill_tuple(TupleDesc tupleDesc,
+ Datum *values, bool *isnull,
+ char *data, Size data_size,
+ uint16 *infomask, bits8 *bit);
+extern bool heap_attisnull(HeapTuple tup, int attnum);
+extern Datum nocachegetattr(HeapTuple tup, int attnum,
+ TupleDesc att);
+extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
+ bool *isnull);
+extern HeapTuple heap_copytuple(HeapTuple tuple);
+extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
+extern HeapTuple heap_form_tuple(TupleDesc tupleDescriptor,
+ Datum *values, bool *isnull);
+extern HeapTuple heap_modify_tuple(HeapTuple tuple,
+ TupleDesc tupleDesc,
+ Datum *replValues,
+ bool *replIsnull,
+ bool *doReplace);
+extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
+ Datum *values, bool *isnull);
+
+/* these three are deprecated versions of the three above: */
+extern HeapTuple heap_formtuple(TupleDesc tupleDescriptor,
+ Datum *values, char *nulls);
+extern HeapTuple heap_modifytuple(HeapTuple tuple,
+ TupleDesc tupleDesc,
+ Datum *replValues,
+ char *replNulls,
+ char *replActions);
+extern void heap_deformtuple(HeapTuple tuple, TupleDesc tupleDesc,
+ Datum *values, char *nulls);
+extern void heap_freetuple(HeapTuple htup);
+extern MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor,
+ Datum *values, bool *isnull);
+extern void heap_free_minimal_tuple(MinimalTuple mtup);
+extern MinimalTuple heap_copy_minimal_tuple(MinimalTuple mtup);
+extern HeapTuple heap_tuple_from_minimal_tuple(MinimalTuple mtup);
+extern MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup);
+
#endif /* HTUP_H */
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