Define a separately configurable XLOG_BLCKSZ symbol for the page size

used within WAL files.  Historically this was the same as the data file
BLCKSZ, but there's no necessary connection, and it's possible that
performance gains might ensue from reducing XLOG_BLCKSZ.  In any case
distinguishing two symbols should improve code clarity.  This commit
does not actually change the page size, only provide the infrastructure
to make it possible to do so.  initdb forced because of addition of a
field to pg_control.
Mark Wong, with some help from Simon Riggs and Tom Lane.

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 82e46bde502c4b97746a652f98615a2b98237ef5..20e63bea75dbab7cf499699cc925633b87557f7f 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Operating System Environment
@@ -1061,7 +1061,7 @@ set semsys:seminfo_semmsl=32
 
       
        
-       8200 (assuming 8K BLCKSZ)
+       8200 (assuming 8K XLOG_BLCKSZ)
       
 
       

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 4cf26cfaa767efed54fbb8521a9b2adb2570ada9..a4ae78bcdef82d23358da936fa6f420f943f7814 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.231 2006/03/31 23:32:05 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.232 2006/04/03 23:35:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -113,10 +113,10 @@
 
 /*
  * Limitation of buffer-alignment for direct IO depends on OS and filesystem,
- * but BLCKSZ is assumed to be enough for it.
+ * but XLOG_BLCKSZ is assumed to be enough for it.
  */
 #ifdef O_DIRECT
-#define ALIGNOF_XLOG_BUFFER        BLCKSZ
+#define ALIGNOF_XLOG_BUFFER        XLOG_BLCKSZ
 #else
 #define ALIGNOF_XLOG_BUFFER        ALIGNOF_BUFFER
 #endif
@@ -374,7 +374,7 @@ typedef struct XLogCtlData
     * and xlblocks values depends on WALInsertLock and WALWriteLock.
     */
    char       *pages;          /* buffers for unwritten XLOG pages */
-   XLogRecPtr *xlblocks;       /* 1st byte ptr-s + BLCKSZ */
+   XLogRecPtr *xlblocks;       /* 1st byte ptr-s + XLOG_BLCKSZ */
    Size        XLogCacheByte;  /* # bytes in xlog buffers */
    int         XLogCacheBlck;  /* highest allocated xlog buffer index */
    TimeLineID  ThisTimeLineID;
@@ -397,7 +397,7 @@ static ControlFileData *ControlFile = NULL;
 
 /* Free space remaining in the current xlog page buffer */
 #define INSERT_FREESPACE(Insert)  \
-   (BLCKSZ - ((Insert)->currpos - (char *) (Insert)->currpage))
+   (XLOG_BLCKSZ - ((Insert)->currpos - (char *) (Insert)->currpage))
 
 /* Construct XLogRecPtr value for current insertion point */
 #define INSERT_RECPTR(recptr,Insert,curridx)  \
@@ -441,7 +441,7 @@ static uint32 readId = 0;
 static uint32 readSeg = 0;
 static uint32 readOff = 0;
 
-/* Buffer for currently read page (BLCKSZ bytes) */
+/* Buffer for currently read page (XLOG_BLCKSZ bytes) */
 static char *readBuf = NULL;
 
 /* Buffer for current ReadRecord result (expandable) */
@@ -706,7 +706,7 @@ begin:;
     * If cache is half filled then try to acquire write lock and do
     * XLogWrite. Ignore any fractional blocks in performing this check.
     */
-   LogwrtRqst.Write.xrecoff -= LogwrtRqst.Write.xrecoff % BLCKSZ;
+   LogwrtRqst.Write.xrecoff -= LogwrtRqst.Write.xrecoff % XLOG_BLCKSZ;
    if (LogwrtRqst.Write.xlogid != LogwrtResult.Write.xlogid ||
        (LogwrtRqst.Write.xrecoff >= LogwrtResult.Write.xrecoff +
         XLogCtl->XLogCacheByte / 2))
@@ -1228,12 +1228,12 @@ AdvanceXLInsertBuffer(void)
    {
        /* crossing a logid boundary */
        NewPageEndPtr.xlogid += 1;
-       NewPageEndPtr.xrecoff = BLCKSZ;
+       NewPageEndPtr.xrecoff = XLOG_BLCKSZ;
    }
    else
-       NewPageEndPtr.xrecoff += BLCKSZ;
+       NewPageEndPtr.xrecoff += XLOG_BLCKSZ;
    XLogCtl->xlblocks[nextidx] = NewPageEndPtr;
-   NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * (Size) BLCKSZ);
+   NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * (Size) XLOG_BLCKSZ);
 
    Insert->curridx = nextidx;
    Insert->currpage = NewPage;
@@ -1244,7 +1244,7 @@ AdvanceXLInsertBuffer(void)
     * Be sure to re-zero the buffer so that bytes beyond what we've written
     * will look like zeroes and not valid XLOG records...
     */
-   MemSet((char *) NewPage, 0, BLCKSZ);
+   MemSet((char *) NewPage, 0, XLOG_BLCKSZ);
 
    /*
     * Fill the new page's header
@@ -1254,7 +1254,7 @@ AdvanceXLInsertBuffer(void)
    /* NewPage->xlp_info = 0; */    /* done by memset */
    NewPage   ->xlp_tli = ThisTimeLineID;
    NewPage   ->xlp_pageaddr.xlogid = NewPageEndPtr.xlogid;
-   NewPage   ->xlp_pageaddr.xrecoff = NewPageEndPtr.xrecoff - BLCKSZ;
+   NewPage   ->xlp_pageaddr.xrecoff = NewPageEndPtr.xrecoff - XLOG_BLCKSZ;
 
    /*
     * If first page of an XLOG segment file, make it a long header.
@@ -1428,7 +1428,7 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
        {
            /* first of group */
            startidx = curridx;
-           startoffset = (LogwrtResult.Write.xrecoff - BLCKSZ) % XLogSegSize;
+           startoffset = (LogwrtResult.Write.xrecoff - XLOG_BLCKSZ) % XLogSegSize;
        }
        npages++;
 
@@ -1439,7 +1439,7 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
         * segment.
         */
        finishing_seg = !ispartialpage &&
-           (startoffset + npages * BLCKSZ) >= XLogSegSize;
+           (startoffset + npages * XLOG_BLCKSZ) >= XLogSegSize;
 
        if (!XLByteLT(LogwrtResult.Write, WriteRqst.Write) ||
            curridx == XLogCtl->XLogCacheBlck ||
@@ -1461,8 +1461,8 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
            }
 
            /* OK to write the page(s) */
-           from = XLogCtl->pages + startidx * (Size) BLCKSZ;
-           nbytes = npages * (Size) BLCKSZ;
+           from = XLogCtl->pages + startidx * (Size) XLOG_BLCKSZ;
+           nbytes = npages * (Size) XLOG_BLCKSZ;
            errno = 0;
            if (write(openLogFile, from, nbytes) != nbytes)
            {
@@ -1720,7 +1720,7 @@ XLogFileInit(uint32 log, uint32 seg,
 {
    char        path[MAXPGPATH];
    char        tmppath[MAXPGPATH];
-   char        zbuffer[BLCKSZ];
+   char        zbuffer[XLOG_BLCKSZ];
    uint32      installed_log;
    uint32      installed_seg;
    int         max_advance;
@@ -1858,7 +1858,7 @@ XLogFileCopy(uint32 log, uint32 seg,
 {
    char        path[MAXPGPATH];
    char        tmppath[MAXPGPATH];
-   char        buffer[BLCKSZ];
+   char        buffer[XLOG_BLCKSZ];
    int         srcfd;
    int         fd;
    int         nbytes;
@@ -2637,7 +2637,7 @@ ReadRecord(XLogRecPtr *RecPtr, int emode)
         * (2) a static char array isn't guaranteed to have any particular
         * alignment, whereas malloc() will provide MAXALIGN'd storage.
         */
-       readBuf = (char *) malloc(BLCKSZ);
+       readBuf = (char *) malloc(XLOG_BLCKSZ);
        Assert(readBuf != NULL);
    }
 
@@ -2651,8 +2651,8 @@ ReadRecord(XLogRecPtr *RecPtr, int emode)
            goto got_record;
        }
        /* align old recptr to next page */
-       if (tmpRecPtr.xrecoff % BLCKSZ != 0)
-           tmpRecPtr.xrecoff += (BLCKSZ - tmpRecPtr.xrecoff % BLCKSZ);
+       if (tmpRecPtr.xrecoff % XLOG_BLCKSZ != 0)
+           tmpRecPtr.xrecoff += (XLOG_BLCKSZ - tmpRecPtr.xrecoff % XLOG_BLCKSZ);
        if (tmpRecPtr.xrecoff >= XLogFileSize)
        {
            (tmpRecPtr.xlogid)++;
@@ -2696,7 +2696,7 @@ ReadRecord(XLogRecPtr *RecPtr, int emode)
        readOff = (uint32) (-1);    /* force read to occur below */
    }
 
-   targetPageOff = ((RecPtr->xrecoff % XLogSegSize) / BLCKSZ) * BLCKSZ;
+   targetPageOff = ((RecPtr->xrecoff % XLogSegSize) / XLOG_BLCKSZ) * XLOG_BLCKSZ;
    if (readOff != targetPageOff)
    {
        readOff = targetPageOff;
@@ -2708,7 +2708,7 @@ ReadRecord(XLogRecPtr *RecPtr, int emode)
                            readId, readSeg, readOff)));
            goto next_record_is_invalid;
        }
-       if (read(readFile, readBuf, BLCKSZ) != BLCKSZ)
+       if (read(readFile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
        {
            ereport(emode,
                    (errcode_for_file_access(),
@@ -2720,7 +2720,7 @@ ReadRecord(XLogRecPtr *RecPtr, int emode)
            goto next_record_is_invalid;
    }
    pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) readBuf);
-   targetRecOff = RecPtr->xrecoff % BLCKSZ;
+   targetRecOff = RecPtr->xrecoff % XLOG_BLCKSZ;
    if (targetRecOff == 0)
    {
        /*
@@ -2746,7 +2746,7 @@ ReadRecord(XLogRecPtr *RecPtr, int emode)
                        RecPtr->xlogid, RecPtr->xrecoff)));
        goto next_record_is_invalid;
    }
-   record = (XLogRecord *) ((char *) readBuf + RecPtr->xrecoff % BLCKSZ);
+   record = (XLogRecord *) ((char *) readBuf + RecPtr->xrecoff % XLOG_BLCKSZ);
 
 got_record:;
 
@@ -2811,17 +2811,18 @@ got_record:;
 
    /*
     * Allocate or enlarge readRecordBuf as needed.  To avoid useless small
-    * increases, round its size to a multiple of BLCKSZ, and make sure it's
-    * at least 4*BLCKSZ to start with.  (That is enough for all "normal"
-    * records, but very large commit or abort records might need more space.)
+    * increases, round its size to a multiple of XLOG_BLCKSZ, and make sure
+    * it's at least 4*Max(BLCKSZ, XLOG_BLCKSZ) to start with.  (That is
+    * enough for all "normal" records, but very large commit or abort records
+    * might need more space.)
     */
    total_len = record->xl_tot_len;
    if (total_len > readRecordBufSize)
    {
        uint32      newSize = total_len;
 
-       newSize += BLCKSZ - (newSize % BLCKSZ);
-       newSize = Max(newSize, 4 * BLCKSZ);
+       newSize += XLOG_BLCKSZ - (newSize % XLOG_BLCKSZ);
+       newSize = Max(newSize, 4 * Max(BLCKSZ, XLOG_BLCKSZ));
        if (readRecordBuf)
            free(readRecordBuf);
        readRecordBuf = (char *) malloc(newSize);
@@ -2839,7 +2840,7 @@ got_record:;
 
    buffer = readRecordBuf;
    nextRecord = NULL;
-   len = BLCKSZ - RecPtr->xrecoff % BLCKSZ;
+   len = XLOG_BLCKSZ - RecPtr->xrecoff % XLOG_BLCKSZ;
    if (total_len > len)
    {
        /* Need to reassemble record */
@@ -2851,7 +2852,7 @@ got_record:;
        buffer += len;
        for (;;)
        {
-           readOff += BLCKSZ;
+           readOff += XLOG_BLCKSZ;
            if (readOff >= XLogSegSize)
            {
                close(readFile);
@@ -2862,7 +2863,7 @@ got_record:;
                    goto next_record_is_invalid;
                readOff = 0;
            }
-           if (read(readFile, readBuf, BLCKSZ) != BLCKSZ)
+           if (read(readFile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
            {
                ereport(emode,
                        (errcode_for_file_access(),
@@ -2890,7 +2891,7 @@ got_record:;
                                readId, readSeg, readOff)));
                goto next_record_is_invalid;
            }
-           len = BLCKSZ - pageHeaderSize - SizeOfXLogContRecord;
+           len = XLOG_BLCKSZ - pageHeaderSize - SizeOfXLogContRecord;
            if (contrecord->xl_rem_len > len)
            {
                memcpy(buffer, (char *) contrecord + SizeOfXLogContRecord, len);
@@ -2905,7 +2906,7 @@ got_record:;
        if (!RecordIsValid(record, *RecPtr, emode))
            goto next_record_is_invalid;
        pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) readBuf);
-       if (BLCKSZ - SizeOfXLogRecord >= pageHeaderSize +
+       if (XLOG_BLCKSZ - SizeOfXLogRecord >= pageHeaderSize +
            MAXALIGN(SizeOfXLogContRecord + contrecord->xl_rem_len))
        {
            nextRecord = (XLogRecord *) ((char *) contrecord +
@@ -2922,7 +2923,7 @@ got_record:;
    /* Record does not cross a page boundary */
    if (!RecordIsValid(record, *RecPtr, emode))
        goto next_record_is_invalid;
-   if (BLCKSZ - SizeOfXLogRecord >= RecPtr->xrecoff % BLCKSZ +
+   if (XLOG_BLCKSZ - SizeOfXLogRecord >= RecPtr->xrecoff % XLOG_BLCKSZ +
        MAXALIGN(total_len))
        nextRecord = (XLogRecord *) ((char *) record + MAXALIGN(total_len));
    EndRecPtr.xlogid = RecPtr->xlogid;
@@ -3404,6 +3405,7 @@ WriteControlFile(void)
 
    ControlFile->blcksz = BLCKSZ;
    ControlFile->relseg_size = RELSEG_SIZE;
+   ControlFile->xlog_blcksz = XLOG_BLCKSZ;
    ControlFile->xlog_seg_size = XLOG_SEG_SIZE;
 
    ControlFile->nameDataLen = NAMEDATALEN;
@@ -3572,6 +3574,13 @@ ReadControlFile(void)
                  " but the server was compiled with RELSEG_SIZE %d.",
                  ControlFile->relseg_size, RELSEG_SIZE),
                 errhint("It looks like you need to recompile or initdb.")));
+   if (ControlFile->xlog_blcksz != XLOG_BLCKSZ)
+       ereport(FATAL,
+               (errmsg("database files are incompatible with server"),
+            errdetail("The database cluster was initialized with XLOG_BLCKSZ %d,"
+                      " but the server was compiled with XLOG_BLCKSZ %d.",
+                      ControlFile->xlog_blcksz, XLOG_BLCKSZ),
+                errhint("It looks like you need to recompile or initdb.")));
    if (ControlFile->xlog_seg_size != XLOG_SEG_SIZE)
        ereport(FATAL,
                (errmsg("database files are incompatible with server"),
@@ -3696,7 +3705,7 @@ XLOGShmemSize(void)
    /* extra alignment padding for XLOG I/O buffers */
    size = add_size(size, ALIGNOF_XLOG_BUFFER);
    /* and the buffers themselves */
-   size = add_size(size, mul_size(BLCKSZ, XLOGbuffers));
+   size = add_size(size, mul_size(XLOG_BLCKSZ, XLOGbuffers));
 
    /*
     * Note: we don't count ControlFileData, it comes out of the "slop factor"
@@ -3743,13 +3752,13 @@ XLOGShmemInit(void)
     */
    allocptr = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, allocptr);
    XLogCtl->pages = allocptr;
-   memset(XLogCtl->pages, 0, (Size) BLCKSZ * XLOGbuffers);
+   memset(XLogCtl->pages, 0, (Size) XLOG_BLCKSZ * XLOGbuffers);
 
    /*
     * Do basic initialization of XLogCtl shared data. (StartupXLOG will fill
     * in additional info.)
     */
-   XLogCtl->XLogCacheByte = (Size) BLCKSZ *XLOGbuffers;
+   XLogCtl->XLogCacheByte = (Size) XLOG_BLCKSZ * XLOGbuffers;
 
    XLogCtl->XLogCacheBlck = XLOGbuffers - 1;
    XLogCtl->Insert.currpage = (XLogPageHeader) (XLogCtl->pages);
@@ -3801,9 +3810,9 @@ BootStrapXLOG(void)
    ThisTimeLineID = 1;
 
    /* page buffer must be aligned suitably for O_DIRECT */
-   buffer = (char *) palloc(BLCKSZ + ALIGNOF_XLOG_BUFFER);
+   buffer = (char *) palloc(XLOG_BLCKSZ + ALIGNOF_XLOG_BUFFER);
    page = (XLogPageHeader) TYPEALIGN(ALIGNOF_XLOG_BUFFER, buffer);
-   memset(page, 0, BLCKSZ);
+   memset(page, 0, XLOG_BLCKSZ);
 
    /* Set up information for the initial checkpoint record */
    checkPoint.redo.xlogid = 0;
@@ -3855,7 +3864,7 @@ BootStrapXLOG(void)
 
    /* Write the first page with the initial record */
    errno = 0;
-   if (write(openLogFile, page, BLCKSZ) != BLCKSZ)
+   if (write(openLogFile, page, XLOG_BLCKSZ) != XLOG_BLCKSZ)
    {
        /* if write didn't set errno, assume problem is no disk space */
        if (errno == 0)
@@ -4712,17 +4721,17 @@ StartupXLOG(void)
    Insert->PrevRecord = LastRec;
    XLogCtl->xlblocks[0].xlogid = openLogId;
    XLogCtl->xlblocks[0].xrecoff =
-       ((EndOfLog.xrecoff - 1) / BLCKSZ + 1) * BLCKSZ;
+       ((EndOfLog.xrecoff - 1) / XLOG_BLCKSZ + 1) * XLOG_BLCKSZ;
 
    /*
     * Tricky point here: readBuf contains the *last* block that the LastRec
     * record spans, not the one it starts in.  The last block is indeed the
     * one we want to use.
     */
-   Assert(readOff == (XLogCtl->xlblocks[0].xrecoff - BLCKSZ) % XLogSegSize);
-   memcpy((char *) Insert->currpage, readBuf, BLCKSZ);
+   Assert(readOff == (XLogCtl->xlblocks[0].xrecoff - XLOG_BLCKSZ) % XLogSegSize);
+   memcpy((char *) Insert->currpage, readBuf, XLOG_BLCKSZ);
    Insert->currpos = (char *) Insert->currpage +
-       (EndOfLog.xrecoff + BLCKSZ - XLogCtl->xlblocks[0].xrecoff);
+       (EndOfLog.xrecoff + XLOG_BLCKSZ - XLogCtl->xlblocks[0].xrecoff);
 
    LogwrtResult.Write = LogwrtResult.Flush = EndOfLog;
 

diff --git a/src/bin/pg_controldata/pg_controldata.c b/src/bin/pg_controldata/pg_controldata.c
index 4e9a9afa0ee9b9a80287d4b25427e8e257ad5fdf..b2d0e01e02630e4b0cb81d6284b929bbd5bdbcd6 100644 (file)
--- a/src/bin/pg_controldata/pg_controldata.c
+++ b/src/bin/pg_controldata/pg_controldata.c
@@ -6,7 +6,7 @@
  * copyright (c) Oliver Elphick , 2001;
  * licence: BSD
  *
- * $PostgreSQL: pgsql/src/bin/pg_controldata/pg_controldata.c,v 1.27 2005/10/15 02:49:37 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_controldata/pg_controldata.c,v 1.28 2006/04/03 23:35:04 tgl Exp $
  */
 #include "postgres.h"
 
@@ -172,6 +172,7 @@ main(int argc, char *argv[])
    /* we don't print floatFormat since can't say much useful about it */
    printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
    printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
+   printf(_("WAL block size:                       %u\n"), ControlFile.xlog_blcksz);
    printf(_("Bytes per WAL segment:                %u\n"), ControlFile.xlog_seg_size);
    printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
    printf(_("Maximum columns in an index:          %u\n"), ControlFile.indexMaxKeys);

diff --git a/src/bin/pg_resetxlog/pg_resetxlog.c b/src/bin/pg_resetxlog/pg_resetxlog.c
index 7b14ad9a2633cc6caa8870f16262c851c5ba5223..c680ecdbb2ca1c8d96e9df99e9d25bd8d23caf6b 100644 (file)
--- a/src/bin/pg_resetxlog/pg_resetxlog.c
+++ b/src/bin/pg_resetxlog/pg_resetxlog.c
@@ -23,7 +23,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.40 2006/03/05 15:58:51 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.41 2006/04/03 23:35:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -457,6 +457,7 @@ GuessControlValues(void)
    ControlFile.floatFormat = FLOATFORMAT_VALUE;
    ControlFile.blcksz = BLCKSZ;
    ControlFile.relseg_size = RELSEG_SIZE;
+   ControlFile.xlog_blcksz = XLOG_BLCKSZ;
    ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
    ControlFile.nameDataLen = NAMEDATALEN;
    ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
@@ -526,6 +527,8 @@ PrintControlValues(bool guessed)
    /* we don't print floatFormat since can't say much useful about it */
    printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
    printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
+   printf(_("WAL block size:                       %u\n"), ControlFile.xlog_blcksz);
+   printf(_("Bytes per WAL segment:                %u\n"), ControlFile.xlog_seg_size);
    printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
    printf(_("Maximum columns in an index:          %u\n"), ControlFile.indexMaxKeys);
    printf(_("Date/time type storage:               %s\n"),
@@ -705,9 +708,9 @@ WriteEmptyXLOG(void)
    int         nbytes;
 
    /* Use malloc() to ensure buffer is MAXALIGNED */
-   buffer = (char *) malloc(BLCKSZ);
+   buffer = (char *) malloc(XLOG_BLCKSZ);
    page = (XLogPageHeader) buffer;
-   memset(buffer, 0, BLCKSZ);
+   memset(buffer, 0, XLOG_BLCKSZ);
 
    /* Set up the XLOG page header */
    page->xlp_magic = XLOG_PAGE_MAGIC;
@@ -756,7 +759,7 @@ WriteEmptyXLOG(void)
    }
 
    errno = 0;
-   if (write(fd, buffer, BLCKSZ) != BLCKSZ)
+   if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
    {
        /* if write didn't set errno, assume problem is no disk space */
        if (errno == 0)
@@ -767,11 +770,11 @@ WriteEmptyXLOG(void)
    }
 
    /* Fill the rest of the file with zeroes */
-   memset(buffer, 0, BLCKSZ);
-   for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
+   memset(buffer, 0, XLOG_BLCKSZ);
+   for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
    {
        errno = 0;
-       if (write(fd, buffer, BLCKSZ) != BLCKSZ)
+       if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
        {
            if (errno == 0)
                errno = ENOSPC;

diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index 9bf46c283195d436db5d84f2707aa7b1c3e03d4e..6fbda53f39eb1ca55454a552c8d778565cc0de13 100644 (file)
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/xlog_internal.h,v 1.11 2006/03/24 04:32:13 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/xlog_internal.h,v 1.12 2006/04/03 23:35:04 tgl Exp $
  */
 #ifndef XLOG_INTERNAL_H
 #define XLOG_INTERNAL_H
@@ -182,8 +182,8 @@ typedef XLogLongPageHeaderData *XLogLongPageHeader;
 
 /* Check if an xrecoff value is in a plausible range */
 #define XRecOffIsValid(xrecoff) \
-       ((xrecoff) % BLCKSZ >= SizeOfXLogShortPHD && \
-       (BLCKSZ - (xrecoff) % BLCKSZ) >= SizeOfXLogRecord)
+       ((xrecoff) % XLOG_BLCKSZ >= SizeOfXLogShortPHD && \
+       (XLOG_BLCKSZ - (xrecoff) % XLOG_BLCKSZ) >= SizeOfXLogRecord)
 
 /*
  * The XLog directory and control file (relative to $PGDATA)

diff --git a/src/include/catalog/pg_control.h b/src/include/catalog/pg_control.h
index a1b123bd37be367d7355c1d0f144a0205be51998..ba54fdc8e6ff4e115b2074beb688b590648a9459 100644 (file)
--- a/src/include/catalog/pg_control.h
+++ b/src/include/catalog/pg_control.h
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_control.h,v 1.27 2006/03/05 15:58:54 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_control.h,v 1.28 2006/04/03 23:35:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,7 +22,7 @@
 
 
 /* Version identifier for this pg_control format */
-#define PG_CONTROL_VERSION 812
+#define PG_CONTROL_VERSION 820
 
 /*
  * Body of CheckPoint XLOG records.  This is declared here because we keep
@@ -126,9 +126,10 @@ typedef struct ControlFileData
     * This data is used to make sure that configuration of this database is
     * compatible with the backend executable.
     */
-   uint32      blcksz;         /* block size for this DB */
+   uint32      blcksz;         /* data block size for this DB */
    uint32      relseg_size;    /* blocks per segment of large relation */
 
+   uint32      xlog_blcksz;    /* block size within WAL files */
    uint32      xlog_seg_size;  /* size of each WAL segment */
 
    uint32      nameDataLen;    /* catalog name field width */

diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index a5170b5f22defc4895adc309bf83597e05030db9..e41b11e8319a2cbb51e36a186ea5d08924e264f4 100644 (file)
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -6,7 +6,7 @@
  * for developers. If you edit any of these, be sure to do a *full*
  * rebuild (and an initdb if noted).
  *
- * $PostgreSQL: pgsql/src/include/pg_config_manual.h,v 1.20 2006/01/05 03:01:37 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/pg_config_manual.h,v 1.21 2006/04/03 23:35:05 tgl Exp $
  *------------------------------------------------------------------------
  */
 
@@ -43,9 +43,20 @@
  */
 #define RELSEG_SIZE (0x40000000 / BLCKSZ)
 
+/*
+ * Size of a WAL file block.  This need have no particular relation to BLCKSZ.
+ * XLOG_BLCKSZ must be a power of 2, and if your system supports O_DIRECT I/O,
+ * XLOG_BLCKSZ must be a multiple of the alignment requirement for direct-I/O
+ * buffers, else direct I/O may fail.
+ *
+ * Changing XLOG_BLCKSZ requires an initdb.
+ */
+#define XLOG_BLCKSZ        8192
+
 /*
  * XLOG_SEG_SIZE is the size of a single WAL file. This must be a power of 2
- * and larger than BLCKSZ (preferably, a great deal larger than BLCKSZ).
+ * and larger than XLOG_BLCKSZ (preferably, a great deal larger than
+ * XLOG_BLCKSZ).
  *
  * Changing XLOG_SEG_SIZE requires an initdb.
  */