This patch, which is built upon the "HeapTupleHeader accessor macros"
patch from 2002-06-10, is supposed to reduce the heap tuple header size by four bytes on most architectures. Of course it changes the on-disk tuple format and therefore requires initdb. This overlays cmin/cmax/xmax fields into only two fields. Manfred Koizar
This commit is contained in:
Bruce Momjian
parent
866103989d
commit
97bfffe50e
@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.139 2002/06/20 20:29:24 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.140 2002/07/02 05:46:14 momjian Exp $
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*
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*
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* INTERFACE ROUTINES
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@ -2204,7 +2204,7 @@ heap_xlog_insert(bool redo, XLogRecPtr lsn, XLogRecord *record)
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htup->t_infomask = HEAP_XMAX_INVALID | xlhdr.mask;
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HeapTupleHeaderSetXmin(htup, record->xl_xid);
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HeapTupleHeaderSetCmin(htup, FirstCommandId);
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HeapTupleHeaderSetXmax(htup, InvalidTransactionId);
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HeapTupleHeaderSetXmaxInvalid(htup);
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HeapTupleHeaderSetCmax(htup, FirstCommandId);
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offnum = PageAddItem(page, (Item) htup, newlen, offnum,
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: htup.h,v 1.54 2002/06/20 20:29:43 momjian Exp $
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* $Id: htup.h,v 1.55 2002/07/02 05:46:14 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -57,15 +57,24 @@
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* Also note that we omit the nulls bitmap if t_infomask shows that there
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* are no nulls in the tuple.
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*/
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/*
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** We store five "virtual" fields Xmin, Cmin, Xmax, Cmax, and Xvac
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** in three physical fields t_xmin, t_cid, t_xmax:
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** CommandId Cmin; insert CID stamp
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** CommandId Cmax; delete CommandId stamp
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** TransactionId Xmin; insert XID stamp
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** TransactionId Xmax; delete XID stamp
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** TransactionId Xvac; used by VACCUUM
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**
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** This assumes, that a CommandId can be stored in a TransactionId.
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*/
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typedef struct HeapTupleHeaderData
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{
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Oid t_oid; /* OID of this tuple -- 4 bytes */
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CommandId t_cmin; /* insert CID stamp -- 4 bytes each */
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CommandId t_cmax; /* delete CommandId stamp */
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TransactionId t_xmin; /* insert XID stamp -- 4 bytes each */
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TransactionId t_xmax; /* delete XID stamp */
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TransactionId t_xmin; /* Xmin -- 4 bytes each */
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TransactionId t_cid; /* Cmin, Cmax, Xvac */
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TransactionId t_xmax; /* Xmax, Cmax */
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ItemPointerData t_ctid; /* current TID of this or newer tuple */
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@ -75,7 +84,7 @@ typedef struct HeapTupleHeaderData
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uint8 t_hoff; /* sizeof header incl. bitmap, padding */
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/* ^ - 31 bytes - ^ */
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/* ^ - 27 bytes - ^ */
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bits8 t_bits[1]; /* bitmap of NULLs -- VARIABLE LENGTH */
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@ -96,6 +105,8 @@ typedef HeapTupleHeaderData *HeapTupleHeader;
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* attribute(s) */
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#define HEAP_HASEXTENDED 0x000C /* the two above combined */
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#define HEAP_XMIN_IS_XMAX 0x0040 /* created and deleted in the */
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/* same transaction */
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#define HEAP_XMAX_UNLOGGED 0x0080 /* to lock tuple for update */
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/* without logging */
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#define HEAP_XMIN_COMMITTED 0x0100 /* t_xmin committed */
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@ -108,6 +119,7 @@ typedef HeapTupleHeaderData *HeapTupleHeader;
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* vacuum */
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#define HEAP_MOVED_IN 0x8000 /* moved from another place by
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* vacuum */
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#define HEAP_MOVED (HEAP_MOVED_OFF | HEAP_MOVED_IN)
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#define HEAP_XACT_MASK 0xFFF0 /* visibility-related bits */
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@ -116,53 +128,100 @@ typedef HeapTupleHeaderData *HeapTupleHeader;
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/* HeapTupleHeader accessor macros */
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#define HeapTupleHeaderGetXmin(tup) \
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((tup)->t_xmin)
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( \
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(tup)->t_xmin \
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)
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#define HeapTupleHeaderGetXmax(tup) \
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((tup)->t_xmax)
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( \
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((tup)->t_infomask & HEAP_XMIN_IS_XMAX) ? \
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(tup)->t_xmin \
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: \
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(tup)->t_xmax \
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)
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/* no AssertMacro, because this is read as a system-defined attribute also */
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/* no AssertMacro, because this is read as a system-defined attribute */
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#define HeapTupleHeaderGetCmin(tup) \
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( \
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(tup)->t_cmin \
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((tup)->t_infomask & HEAP_MOVED) ? \
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FirstCommandId \
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: \
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( \
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((tup)->t_infomask & (HEAP_XMIN_IS_XMAX | HEAP_XMAX_INVALID)) ? \
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(CommandId) (tup)->t_cid \
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: \
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FirstCommandId \
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) \
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)
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#define HeapTupleHeaderGetCmax(tup) \
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((tup)->t_cmax)
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( \
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((tup)->t_infomask & HEAP_MOVED) ? \
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FirstCommandId \
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: \
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( \
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((tup)->t_infomask & (HEAP_XMIN_IS_XMAX | HEAP_XMAX_INVALID)) ? \
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(CommandId) (tup)->t_xmax \
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: \
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(CommandId) (tup)->t_cid \
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) \
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)
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#define HeapTupleHeaderGetXvac(tup) \
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( \
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AssertMacro((tup)->t_infomask & (HEAP_MOVED_IN | HEAP_MOVED_OFF)), \
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(TransactionId) (tup)->t_cmin \
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AssertMacro((tup)->t_infomask & HEAP_MOVED), \
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(tup)->t_cid \
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)
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#define HeapTupleHeaderSetXmin(tup, xid) \
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(TransactionIdStore((xid), &(tup)->t_xmin))
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( \
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TransactionIdStore((xid), &(tup)->t_xmin) \
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)
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#define HeapTupleHeaderSetXminInvalid(tup) \
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(StoreInvalidTransactionId(&(tup)->t_xmin))
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do { \
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(tup)->t_infomask &= ~HEAP_XMIN_IS_XMAX; \
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StoreInvalidTransactionId(&(tup)->t_xmin); \
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} while (0)
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#define HeapTupleHeaderSetXmax(tup, xid) \
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(TransactionIdStore((xid), &(tup)->t_xmax))
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do { \
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if (TransactionIdEquals((tup)->t_xmin, (xid))) \
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(tup)->t_infomask |= HEAP_XMIN_IS_XMAX; \
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else \
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{ \
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(tup)->t_infomask &= ~HEAP_XMIN_IS_XMAX; \
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TransactionIdStore((xid), &(tup)->t_xmax); \
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} \
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} while (0)
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#define HeapTupleHeaderSetXmaxInvalid(tup) \
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(StoreInvalidTransactionId(&(tup)->t_xmax))
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do { \
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(tup)->t_infomask &= ~HEAP_XMIN_IS_XMAX; \
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StoreInvalidTransactionId(&(tup)->t_xmax); \
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} while (0)
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#define HeapTupleHeaderSetCmin(tup, cid) \
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( \
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AssertMacro(!((tup)->t_infomask & (HEAP_MOVED_IN | HEAP_MOVED_OFF))), \
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(tup)->t_cmin = (cid) \
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)
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do { \
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Assert(!((tup)->t_infomask & HEAP_MOVED)); \
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TransactionIdStore((TransactionId) (cid), &(tup)->t_cid); \
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} while (0)
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#define HeapTupleHeaderSetCmax(tup, cid) \
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((tup)->t_cmax = (cid))
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do { \
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Assert(!((tup)->t_infomask & HEAP_MOVED)); \
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if ((tup)->t_infomask & HEAP_XMIN_IS_XMAX) \
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TransactionIdStore((TransactionId) (cid), &(tup)->t_xmax); \
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else \
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TransactionIdStore((TransactionId) (cid), &(tup)->t_cid); \
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} while (0)
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#define HeapTupleHeaderSetXvac(tup, xid) \
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( \
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AssertMacro((tup)->t_infomask & (HEAP_MOVED_IN | HEAP_MOVED_OFF)), \
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TransactionIdStore((xid), (TransactionId *) &((tup)->t_cmin)) \
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)
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do { \
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Assert((tup)->t_infomask & HEAP_MOVED); \
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TransactionIdStore((xid), &(tup)->t_cid); \
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} while (0)
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/*
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@ -37,7 +37,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: catversion.h,v 1.136 2002/06/20 20:29:43 momjian Exp $
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* $Id: catversion.h,v 1.137 2002/07/02 05:46:14 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -53,6 +53,6 @@
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*/
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/* yyyymmddN */
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#define CATALOG_VERSION_NO 200206151
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#define CATALOG_VERSION_NO 200207021
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#endif
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