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Invent WAL timelines, as per recent discussion, to make point-in-time

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recovery more manageable.  Also, undo recent change to add FILE_HEADER
and WASTED_SPACE records to XLOG; instead make the XLOG page header
variable-size with extra fields in the first page of an XLOG file.
This should fix the boundary-case bugs observed by Mark Kirkwood.
initdb forced due to change of XLOG representation.
This commit is contained in:
Tom Lane
2004-07-21 22:31:26 +00:00
parent 8d3517dc1f
commit 2042b3428d
26 changed files with 1322 additions and 982 deletions
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108
src/include/access/xlog.h
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@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/access/xlog.h,v 1.53 2004/07/19 02:47:13 tgl Exp $
* $PostgreSQL: pgsql/src/include/access/xlog.h,v 1.54 2004/07/21 22:31:25 tgl Exp $
*/
#ifndef XLOG_H
#define XLOG_H
@@ -14,7 +14,7 @@
#include "access/rmgr.h"
#include "access/transam.h"
#include "access/xlogdefs.h"
#include "storage/bufmgr.h"
#include "storage/buf.h"
#include "utils/pg_crc.h"
@@ -76,107 +76,6 @@ typedef struct XLogRecord
#define XLOG_NO_TRAN XLR_INFO_MASK
/*
* Header info for a backup block appended to an XLOG record.
*
* Note that the backup block has its own CRC, and is not covered by
* the CRC of the XLOG record proper. Also note that we don't attempt
* to align either the BkpBlock struct or the block's data.
*/
typedef struct BkpBlock
{
crc64 crc;
RelFileNode node;
BlockNumber block;
} BkpBlock;
/*
* When there is not enough space on current page for whole record, we
* continue on the next page with continuation record. (However, the
* XLogRecord header will never be split across pages; if there's less than
* SizeOfXLogRecord space left at the end of a page, we just waste it.)
*
* Note that xl_rem_len includes backup-block data, unlike xl_len in the
* initial header.
*/
typedef struct XLogContRecord
{
uint32 xl_rem_len; /* total len of remaining data for record */
/* ACTUAL LOG DATA FOLLOWS AT END OF STRUCT */
} XLogContRecord;
#define SizeOfXLogContRecord MAXALIGN(sizeof(XLogContRecord))
/*
* Each page of XLOG file has a header like this:
*/
#define XLOG_PAGE_MAGIC 0xD05B /* can be used as WAL version indicator */
typedef struct XLogPageHeaderData
{
uint16 xlp_magic; /* magic value for correctness checks */
uint16 xlp_info; /* flag bits, see below */
StartUpID xlp_sui; /* StartUpID of first record on page */
XLogRecPtr xlp_pageaddr; /* XLOG address of this page */
} XLogPageHeaderData;
#define SizeOfXLogPHD MAXALIGN(sizeof(XLogPageHeaderData))
typedef XLogPageHeaderData *XLogPageHeader;
/* When record crosses page boundary, set this flag in new page's header */
#define XLP_FIRST_IS_CONTRECORD 0x0001
/* All defined flag bits in xlp_info (used for validity checking of header) */
#define XLP_ALL_FLAGS 0x0001
/*
* We break each logical log file (xlogid value) into segment files of the
* size indicated by XLOG_SEG_SIZE. One possible segment at the end of each
* log file is wasted, to ensure that we don't have problems representing
* last-byte-position-plus-1.
*/
#define XLogSegSize ((uint32) XLOG_SEG_SIZE)
#define XLogSegsPerFile (((uint32) 0xffffffff) / XLogSegSize)
#define XLogFileSize (XLogSegsPerFile * XLogSegSize)
/*
* The first XLOG record in each segment file is always an XLOG_FILE_HEADER
* record. This record does nothing as far as XLOG replay is concerned,
* but it is useful for verifying that we haven't mixed up XLOG segment files.
* The body of an XLOG_FILE_HEADER record is a struct XLogFileHeaderData.
* Note: the xlogid/segno fields are really redundant with xlp_pageaddr in
* the page header, but we store them anyway as an extra check.
*/
typedef struct XLogFileHeaderData
{
uint64 xlfhd_sysid; /* system identifier from pg_control */
uint32 xlfhd_xlogid; /* logical log file # */
uint32 xlfhd_segno; /* segment number within logical log file */
uint32 xlfhd_seg_size; /* just as a cross-check */
} XLogFileHeaderData;
#define SizeOfXLogFHD MAXALIGN(sizeof(XLogFileHeaderData))
/*
* Method table for resource managers.
*
* RmgrTable[] is indexed by RmgrId values (see rmgr.h).
*/
typedef struct RmgrData
{
const char *rm_name;
void (*rm_redo) (XLogRecPtr lsn, XLogRecord *rptr);
void (*rm_undo) (XLogRecPtr lsn, XLogRecord *rptr);
void (*rm_desc) (char *buf, uint8 xl_info, char *rec);
void (*rm_startup) (void);
void (*rm_cleanup) (void);
} RmgrData;
extern RmgrData RmgrTable[];
/*--------------------
* List of these structs is used to pass data to XLogInsert().
*
* If buffer is valid then XLOG will check if buffer must be backed up
@@ -188,7 +87,6 @@ extern RmgrData RmgrTable[];
* the XLOG record, since we assume it's present in the buffer. Therefore,
* rmgr redo routines MUST pay attention to XLR_BKP_BLOCK_X to know what
* is actually stored in the XLOG record.
*--------------------
*/
typedef struct XLogRecData
{
@@ -198,7 +96,7 @@ typedef struct XLogRecData
struct XLogRecData *next;
} XLogRecData;
extern StartUpID ThisStartUpID; /* current SUI */
extern TimeLineID ThisTimeLineID; /* current TLI */
extern bool InRecovery;
extern XLogRecPtr MyLastRecPtr;
extern bool MyXactMadeXLogEntry;