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postgresql/src/include/access/gistxlog.h

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Split index xlog headers from other private index headers. The xlog-specific headers need to be included in both frontend code - specifically, pg_waldump - and the backend, but the remainder of the private headers for each index are only needed by the backend. By splitting the xlog stuff out into separate headers, pg_waldump pulls in fewer backend headers, which is a good thing. Patch by me, reviewed by Michael Paquier and Andres Freund, per a complaint from Dilip Kumar. Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
2017-02-14 21:37:59 +01:00
/*-------------------------------------------------------------------------
*
* gistxlog.h
* gist xlog routines
*
Update copyright for 2019 Backpatch-through: certain files through 9.4
2019-01-02 18:44:25 +01:00
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
Split index xlog headers from other private index headers. The xlog-specific headers need to be included in both frontend code - specifically, pg_waldump - and the backend, but the remainder of the private headers for each index are only needed by the backend. By splitting the xlog stuff out into separate headers, pg_waldump pulls in fewer backend headers, which is a good thing. Patch by me, reviewed by Michael Paquier and Andres Freund, per a complaint from Dilip Kumar. Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
2017-02-14 21:37:59 +01:00
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/access/gistxlog.h
*
*-------------------------------------------------------------------------
*/
#ifndef GIST_XLOG_H
#define GIST_XLOG_H
#include "access/gist.h"
#include "access/xlogreader.h"
#include "lib/stringinfo.h"
#define XLOG_GIST_PAGE_UPDATE 0x00
Check for conflicting queries during replay of gistvacuumpage() 013ebc0a7b implements so-called GiST microvacuum. That is gistgettuple() marks index tuples as dead when kill_prior_tuple is set. Later, when new tuple insertion claims page space, those dead index tuples are physically deleted from page. When this deletion is replayed on standby, it might conflict with read-only queries. But 013ebc0a7b doesn't handle this. That may lead to disappearance of some tuples from read-only snapshots on standby. This commit implements resolving of conflicts between replay of GiST microvacuum and standby queries. On the master we implement new WAL record type XLOG_GIST_DELETE, which comprises necessary information. On stable releases we've to be tricky to keep WAL compatibility. Information required for conflict processing is just appended to data of XLOG_GIST_PAGE_UPDATE record. So, PostgreSQL version, which doesn't know about conflict processing, will just ignore that. Reported-by: Andres Freund Diagnosed-by: Andres Freund Discussion: https://postgr.es/m/20181212224524.scafnlyjindmrbe6%40alap3.anarazel.de Author: Alexander Korotkov Backpatch-through: 9.6
2018-12-21 00:37:37 +01:00
#define XLOG_GIST_DELETE 0x10 /* delete leaf index tuples for a page */
Split index xlog headers from other private index headers. The xlog-specific headers need to be included in both frontend code - specifically, pg_waldump - and the backend, but the remainder of the private headers for each index are only needed by the backend. By splitting the xlog stuff out into separate headers, pg_waldump pulls in fewer backend headers, which is a good thing. Patch by me, reviewed by Michael Paquier and Andres Freund, per a complaint from Dilip Kumar. Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
2017-02-14 21:37:59 +01:00
/* #define XLOG_GIST_NEW_ROOT 0x20 */ /* not used anymore */
#define XLOG_GIST_PAGE_SPLIT 0x30
/* #define XLOG_GIST_INSERT_COMPLETE 0x40 */ /* not used anymore */
#define XLOG_GIST_CREATE_INDEX 0x50
/* #define XLOG_GIST_PAGE_DELETE 0x60 */ /* not used anymore */
/*
* Backup Blk 0: updated page.
* Backup Blk 1: If this operation completes a page split, by inserting a
* downlink for the split page, the left half of the split
*/
typedef struct gistxlogPageUpdate
{
/* number of deleted offsets */
uint16 ntodelete;
uint16 ntoinsert;
/*
* In payload of blk 0 : 1. todelete OffsetNumbers 2. tuples to insert
*/
} gistxlogPageUpdate;
Check for conflicting queries during replay of gistvacuumpage() 013ebc0a7b implements so-called GiST microvacuum. That is gistgettuple() marks index tuples as dead when kill_prior_tuple is set. Later, when new tuple insertion claims page space, those dead index tuples are physically deleted from page. When this deletion is replayed on standby, it might conflict with read-only queries. But 013ebc0a7b doesn't handle this. That may lead to disappearance of some tuples from read-only snapshots on standby. This commit implements resolving of conflicts between replay of GiST microvacuum and standby queries. On the master we implement new WAL record type XLOG_GIST_DELETE, which comprises necessary information. On stable releases we've to be tricky to keep WAL compatibility. Information required for conflict processing is just appended to data of XLOG_GIST_PAGE_UPDATE record. So, PostgreSQL version, which doesn't know about conflict processing, will just ignore that. Reported-by: Andres Freund Diagnosed-by: Andres Freund Discussion: https://postgr.es/m/20181212224524.scafnlyjindmrbe6%40alap3.anarazel.de Author: Alexander Korotkov Backpatch-through: 9.6
2018-12-21 00:37:37 +01:00
/*
* Backup Blk 0: Leaf page, whose index tuples are deleted.
*/
typedef struct gistxlogDelete
{
RelFileNode hnode; /* RelFileNode of the heap the index currently
* points at */
uint16 ntodelete; /* number of deleted offsets */
/*
* In payload of blk 0 : todelete OffsetNumbers
*/
} gistxlogDelete;
#define SizeOfGistxlogDelete (offsetof(gistxlogDelete, ntodelete) + sizeof(uint16))
Split index xlog headers from other private index headers. The xlog-specific headers need to be included in both frontend code - specifically, pg_waldump - and the backend, but the remainder of the private headers for each index are only needed by the backend. By splitting the xlog stuff out into separate headers, pg_waldump pulls in fewer backend headers, which is a good thing. Patch by me, reviewed by Michael Paquier and Andres Freund, per a complaint from Dilip Kumar. Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
2017-02-14 21:37:59 +01:00
/*
* Backup Blk 0: If this operation completes a page split, by inserting a
* downlink for the split page, the left half of the split
* Backup Blk 1 - npage: split pages (1 is the original page)
*/
typedef struct gistxlogPageSplit
{
BlockNumber origrlink; /* rightlink of the page before split */
GistNSN orignsn; /* NSN of the page before split */
bool origleaf; /* was splitted page a leaf page? */
uint16 npage; /* # of pages in the split */
bool markfollowright; /* set F_FOLLOW_RIGHT flags */
/*
* follow: 1. gistxlogPage and array of IndexTupleData per page
*/
} gistxlogPageSplit;
extern void gist_redo(XLogReaderState *record);
extern void gist_desc(StringInfo buf, XLogReaderState *record);
extern const char *gist_identify(uint8 info);
extern void gist_xlog_startup(void);
extern void gist_xlog_cleanup(void);
extern void gist_mask(char *pagedata, BlockNumber blkno);
#endif