OK...here is a patch that will cause the magnetic disk storage

manager to not try to split files in 2 gig chunks.  It will just
try to get another block.

If applied, everything is just as before. But if LET_OS_MANAGE_FILESIZE
is defined, the chaining disappears and the file just keeps on
going, and going, and going, til the OS barfs.

Darren King

diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index e470fa34f161aa38c9f4630df2a54acc19af8514..8f3611e268b913c67a4ca51f58c31880eefcc9b8 100644 (file)
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.29 1998/02/26 04:36:16 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.30 1998/03/20 04:22:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,9 @@ typedef struct _MdfdVec
    uint16      mdfd_flags;     /* clean, dirty, free */
    int         mdfd_lstbcnt;   /* most recent block count */
    int         mdfd_nextFree;  /* next free vector */
+#ifndef LET_OS_MANAGE_FILESIZE
    struct _MdfdVec *mdfd_chain;/* for large relations */
+#endif
 } MdfdVec;
 
 static int Nfds = 100;
@@ -70,9 +72,16 @@ static MemoryContext MdCxt;
  *          (((2 ** 23) / BLCKSZ) * (2 ** 8))
  *
  * 07 Jan 98  darrenk
+ *
+ * Now possibly let the OS handle it...
+ *
+ * 19 Mar 98  darrenk
+ *
  */
 
+#ifndef LET_OS_MANAGE_FILESIZE
 #define RELSEG_SIZE        ((8388608 / BLCKSZ) * 256)
+#endif
 
 /* routines declared here */
 static MdfdVec *_mdfd_openseg(Relation reln, int segno, int oflags);
@@ -159,7 +168,9 @@ mdcreate(Relation reln)
 
    Md_fdvec[vfd].mdfd_vfd = fd;
    Md_fdvec[vfd].mdfd_flags = (uint16) 0;
+#ifndef LET_OS_MANAGE_FILESIZE
    Md_fdvec[vfd].mdfd_chain = (MdfdVec *) NULL;
+#endif
    Md_fdvec[vfd].mdfd_lstbcnt = 0;
 
    return (vfd);
@@ -203,6 +214,7 @@ mdunlink(Relation reln)
    Md_fdvec[fd].mdfd_flags = (uint16) 0;
 
    oldcxt = MemoryContextSwitchTo(MdCxt);
+#ifndef LET_OS_MANAGE_FILESIZE
    for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL;)
    {
        FileUnlink(v->mdfd_vfd);
@@ -212,6 +224,13 @@ mdunlink(Relation reln)
            pfree(ov);
    }
    Md_fdvec[fd].mdfd_chain = (MdfdVec *) NULL;
+#else
+   v = &Md_fdvec[fd];
+   if (v != (MdfdVec *) NULL)
+   {
+       FileUnlink(v->mdfd_vfd);
+   }
+#endif
    MemoryContextSwitchTo(oldcxt);
 
    _fdvec_free(fd);
@@ -245,6 +264,7 @@ mdextend(Relation reln, char *buffer)
    v->mdfd_flags |= MDFD_DIRTY;
 
    /* try to keep the last block count current, though it's just a hint */
+#ifndef LET_OS_MANAGE_FILESIZE
    if ((v->mdfd_lstbcnt = (++nblocks % RELSEG_SIZE)) == 0)
        v->mdfd_lstbcnt = RELSEG_SIZE;
 
@@ -253,6 +273,9 @@ mdextend(Relation reln, char *buffer)
        || v->mdfd_lstbcnt > RELSEG_SIZE)
        elog(FATAL, "segment too big!");
 #endif
+#else
+   v->mdfd_lstbcnt = ++nblocks;
+#endif
 
    return (SM_SUCCESS);
 }
@@ -281,12 +304,14 @@ mdopen(Relation reln)
 
    Md_fdvec[vfd].mdfd_vfd = fd;
    Md_fdvec[vfd].mdfd_flags = (uint16) 0;
-   Md_fdvec[vfd].mdfd_chain = (MdfdVec *) NULL;
    Md_fdvec[vfd].mdfd_lstbcnt = _mdnblocks(fd, BLCKSZ);
+#ifndef LET_OS_MANAGE_FILESIZE
+   Md_fdvec[vfd].mdfd_chain = (MdfdVec *) NULL;
 
 #ifdef DIAGNOSTIC
    if (Md_fdvec[vfd].mdfd_lstbcnt > RELSEG_SIZE)
        elog(FATAL, "segment too big on relopen!");
+#endif
 #endif
 
    return (vfd);
@@ -311,6 +336,7 @@ mdclose(Relation reln)
    fd = RelationGetFile(reln);
 
    oldcxt = MemoryContextSwitchTo(MdCxt);
+#ifndef LET_OS_MANAGE_FILESIZE
    for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL;)
    {
        /* if not closed already */
@@ -335,8 +361,28 @@ mdclose(Relation reln)
            pfree(ov);
    }
 
-   MemoryContextSwitchTo(oldcxt);
    Md_fdvec[fd].mdfd_chain = (MdfdVec *) NULL;
+#else
+   v = &Md_fdvec[fd];
+   if (v != (MdfdVec *) NULL)
+   {
+       if (v->mdfd_vfd >= 0)
+       {
+
+           /*
+            * We sync the file descriptor so that we don't need to reopen
+            * it at transaction commit to force changes to disk.
+            */
+
+           FileSync(v->mdfd_vfd);
+           FileClose(v->mdfd_vfd);
+
+           /* mark this file descriptor as clean in our private table */
+           v->mdfd_flags &= ~MDFD_DIRTY;
+       }
+   }
+#endif
+   MemoryContextSwitchTo(oldcxt);
 
    _fdvec_free(fd);
 
@@ -358,12 +404,16 @@ mdread(Relation reln, BlockNumber blocknum, char *buffer)
 
    v = _mdfd_getseg(reln, blocknum, 0);
 
+#ifndef LET_OS_MANAGE_FILESIZE
    seekpos = (long) (BLCKSZ * (blocknum % RELSEG_SIZE));
 
 #ifdef DIAGNOSTIC
    if (seekpos >= BLCKSZ * RELSEG_SIZE)
        elog(FATAL, "seekpos too big!");
 #endif
+#else
+   seekpos = (long) (BLCKSZ * (blocknum));
+#endif
 
    if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
    {
@@ -400,11 +450,15 @@ mdwrite(Relation reln, BlockNumber blocknum, char *buffer)
 
    v = _mdfd_getseg(reln, blocknum, 0);
 
+#ifndef LET_OS_MANAGE_FILESIZE
    seekpos = (long) (BLCKSZ * (blocknum % RELSEG_SIZE));
 #ifdef DIAGNOSTIC
    if (seekpos >= BLCKSZ * RELSEG_SIZE)
        elog(FATAL, "seekpos too big!");
 #endif
+#else
+   seekpos = (long) (BLCKSZ * (blocknum));
+#endif
 
    if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
    {
@@ -435,11 +489,15 @@ mdflush(Relation reln, BlockNumber blocknum, char *buffer)
 
    v = _mdfd_getseg(reln, blocknum, 0);
 
+#ifndef LET_OS_MANAGE_FILESIZE
    seekpos = (long) (BLCKSZ * (blocknum % RELSEG_SIZE));
 #ifdef DIAGNOSTIC
    if (seekpos >= BLCKSZ * RELSEG_SIZE)
        elog(FATAL, "seekpos too big!");
 #endif
+#else
+   seekpos = (long) (BLCKSZ * (blocknum));
+#endif
 
    if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
    {
@@ -483,6 +541,8 @@ mdblindwrt(char *dbstr,
    long        seekpos;
    int         status;
    char       *path;
+
+#ifndef LET_OS_MANAGE_FILESIZE
    int         nchars;
 
    /* be sure we have enough space for the '.segno', if any */
@@ -535,12 +595,53 @@ mdblindwrt(char *dbstr,
            sprintf(path, "%s%c%s.%d", tmpPath, SEP_CHAR, relstr, segno);
        pfree(tmpPath);
    }
+#else
+   /* construct the path to the file and open it */
+   /* system table? then put in system area... */
+   if (dbid == (Oid) 0)
+   {
+       path = (char *) palloc(strlen(DataDir) + sizeof(NameData) + 2);
+       sprintf(path, "%s/%s", DataDir, relstr);
+   }
+   /* user table? then put in user database area... */
+   else if (dbid == MyDatabaseId)
+   {
+       extern char *DatabasePath;
+
+       path = (char *) palloc(strlen(DatabasePath) + 2 * sizeof(NameData) + 2);
+       sprintf(path, "%s%c%s", DatabasePath, SEP_CHAR, relstr);
+   }
+   else
+/* this is work arround only !!! */
+   {
+       char        dbpath[MAXPGPATH + 1];
+       Oid         owner,
+                   id;
+       char       *tmpPath;
+
+       GetRawDatabaseInfo(dbstr, &owner, &id, dbpath);
+
+       if (id != dbid)
+           elog(FATAL, "mdblindwrt: oid of db %s is not %u", dbstr, dbid);
+       tmpPath = ExpandDatabasePath(dbpath);
+       if (tmpPath == NULL)
+           elog(FATAL, "mdblindwrt: can't expand path for db %s", dbstr);
+       path = (char *) palloc(strlen(tmpPath) + 2 * sizeof(NameData) + 2);
+       sprintf(path, "%s%c%s", tmpPath, SEP_CHAR, relstr);
+       pfree(tmpPath);
+   }
+#endif
 
    if ((fd = open(path, O_RDWR, 0600)) < 0)
        return (SM_FAIL);
 
    /* seek to the right spot */
+#ifndef LET_OS_MANAGE_FILESIZE
    seekpos = (long) (BLCKSZ * (blkno % RELSEG_SIZE));
+#else
+   seekpos = (long) (BLCKSZ * (blkno));
+#endif
+
    if (lseek(fd, seekpos, SEEK_SET) != seekpos)
    {
        close(fd);
@@ -577,6 +678,7 @@ mdnblocks(Relation reln)
    fd = RelationGetFile(reln);
    v = &Md_fdvec[fd];
 
+#ifndef LET_OS_MANAGE_FILESIZE
 #ifdef DIAGNOSTIC
    if (_mdnblocks(v->mdfd_vfd, BLCKSZ) > RELSEG_SIZE)
        elog(FATAL, "segment too big in getseg!");
@@ -607,6 +709,9 @@ mdnblocks(Relation reln)
            return ((segno * RELSEG_SIZE) + nblocks);
        }
    }
+#else
+   return (_mdnblocks(v->mdfd_vfd, BLCKSZ));
+#endif
 }
 
 /*
@@ -619,6 +724,8 @@ mdtruncate(Relation reln, int nblocks)
 {
    int         fd;
    MdfdVec    *v;
+
+#ifndef LET_OS_MANAGE_FILESIZE
    int         curnblk;
 
    curnblk = mdnblocks(reln);
@@ -628,6 +735,7 @@ mdtruncate(Relation reln, int nblocks)
             &(reln->rd_rel->relname.data[0]));
        return (curnblk);
    }
+#endif
 
    fd = RelationGetFile(reln);
    v = &Md_fdvec[fd];
@@ -657,7 +765,12 @@ mdcommit()
 
    for (i = 0; i < CurFd; i++)
    {
+#ifndef LET_OS_MANAGE_FILESIZE
        for (v = &Md_fdvec[i]; v != (MdfdVec *) NULL; v = v->mdfd_chain)
+#else
+       v = &Md_fdvec[i];
+       if (v != (MdfdVec *) NULL)
+#endif
        {
            if (v->mdfd_flags & MDFD_DIRTY)
            {
@@ -686,7 +799,12 @@ mdabort()
 
    for (i = 0; i < CurFd; i++)
    {
+#ifndef LET_OS_MANAGE_FILESIZE
        for (v = &Md_fdvec[i]; v != (MdfdVec *) NULL; v = v->mdfd_chain)
+#else
+       v = &Md_fdvec[i];
+       if (v != (MdfdVec *) NULL)
+#endif
        {
            v->mdfd_flags &= ~MDFD_DIRTY;
        }
@@ -812,12 +930,14 @@ _mdfd_openseg(Relation reln, int segno, int oflags)
    /* fill the entry */
    v->mdfd_vfd = fd;
    v->mdfd_flags = (uint16) 0;
-   v->mdfd_chain = (MdfdVec *) NULL;
    v->mdfd_lstbcnt = _mdnblocks(fd, BLCKSZ);
+#ifndef LET_OS_MANAGE_FILESIZE
+   v->mdfd_chain = (MdfdVec *) NULL;
 
 #ifdef DIAGNOSTIC
    if (v->mdfd_lstbcnt > RELSEG_SIZE)
        elog(FATAL, "segment too big on open!");
+#endif
 #endif
 
    /* all done */
@@ -841,6 +961,7 @@ _mdfd_getseg(Relation reln, int blkno, int oflag)
        reln->rd_fd = fd;
    }
 
+#ifndef LET_OS_MANAGE_FILESIZE
    for (v = &Md_fdvec[fd], segno = blkno / RELSEG_SIZE, i = 1;
         segno > 0;
         i++, segno--)
@@ -856,6 +977,9 @@ _mdfd_getseg(Relation reln, int blkno, int oflag)
        }
        v = v->mdfd_chain;
    }
+#else
+   v = &Md_fdvec[fd];
+#endif
 
    return (v);
 }