Re: [HACKERS] tables > 1 gig

Thank you. Applied.

[Charset iso-8859-1 unsupported, filtering to ASCII...]
> >
> > > > Yes, I can see your point. It would show them different views of the
> > > > table.
> > > >
> > > > So, as you were saying, we have no way of invalidating file
> > descriptors
> > > > of other backends for secondary segments.
> > >
> > > > Why does truncating the file
> > > > not work? Any ideas?
> > > >
> > >
> > > I have gotten no bug reports for my trial implementation.
> > > AFAIK,only Ole Gjerde has tested my patch.
> > > Is it sufficient ?
> >
> > Yes. We need something, and maybe after we add it, people can do
> > testing and find any problems. It is better to apply it than to leave
> > it as it currently exists, no?
> >
>
> OK,here is my patch for PostgreSQL6.5-release.
>
> Regards.
>
> Hiroshi Inoue
> Inoue(at)tpf(dot)co(dot)jp
>
> *** storage/smgr/md.c.orig Fri Jun 11 12:20:06 1999
> --- storage/smgr/md.c Fri Jun 18 15:10:54 1999
> ***************
> *** 674,684 ****
> segno = 0;
> for (;;)
> {
> ! if (v->mdfd_lstbcnt == RELSEG_SIZE
> ! || (nblocks = _mdnblocks(v->mdfd_vfd, BLCKSZ)) == RELSEG_SIZE)
> {
> -
> - v->mdfd_lstbcnt = RELSEG_SIZE;
> segno++;
>
> if (v->mdfd_chain == (MdfdVec *) NULL)
> --- 674,685 ----
> segno = 0;
> for (;;)
> {
> ! nblocks = _mdnblocks(v->mdfd_vfd, BLCKSZ);
> ! if (nblocks > RELSEG_SIZE)
> ! elog(FATAL, "segment too big in mdnblocks!");
> ! v->mdfd_lstbcnt = nblocks;
> ! if (nblocks == RELSEG_SIZE)
> {
> segno++;
>
> if (v->mdfd_chain == (MdfdVec *) NULL)
> ***************
> *** 711,732 ****
> MdfdVec *v;
>
> #ifndef LET_OS_MANAGE_FILESIZE
> ! int curnblk;
>
> curnblk = mdnblocks(reln);
> ! if (curnblk / RELSEG_SIZE > 0)
> ! {
> ! elog(NOTICE, "Can't truncate multi-segments relation %s",
> ! reln->rd_rel->relname.data);
> ! return curnblk;
> ! }
> #endif
>
> fd = RelationGetFile(reln);
> v = &Md_fdvec[fd];
>
> if (FileTruncate(v->mdfd_vfd, nblocks * BLCKSZ) < 0)
> return -1;
>
> return nblocks;
>
> --- 712,766 ----
> MdfdVec *v;
>
> #ifndef LET_OS_MANAGE_FILESIZE
> ! int curnblk,
> ! i,
> ! oldsegno,
> ! newsegno,
> ! lastsegblocks;
> ! MdfdVec **varray;
>
> curnblk = mdnblocks(reln);
> ! if (nblocks > curnblk)
> ! return -1;
> ! oldsegno = curnblk / RELSEG_SIZE;
> ! newsegno = nblocks / RELSEG_SIZE;
> !
> #endif
>
> fd = RelationGetFile(reln);
> v = &Md_fdvec[fd];
>
> + #ifndef LET_OS_MANAGE_FILESIZE
> + varray = (MdfdVec **)palloc((oldsegno + 1) * sizeof(MdfdVec *));
> + for (i = 0; i <= oldsegno; i++)
> + {
> + if (!v)
> + elog(ERROR,"segment isn't open in mdtruncate!");
> + varray[i] = v;
> + v = v->mdfd_chain;
> + }
> + for (i = oldsegno; i > newsegno; i--)
> + {
> + v = varray[i];
> + if (FileTruncate(v->mdfd_vfd, 0) < 0)
> + {
> + pfree(varray);
> + return -1;
> + }
> + v->mdfd_lstbcnt = 0;
> + }
> + /* Calculate the # of blocks in the last segment */
> + lastsegblocks = nblocks - (newsegno * RELSEG_SIZE);
> + v = varray[i];
> + pfree(varray);
> + if (FileTruncate(v->mdfd_vfd, lastsegblocks * BLCKSZ) < 0)
> + return -1;
> + v->mdfd_lstbcnt = lastsegblocks;
> + #else
> if (FileTruncate(v->mdfd_vfd, nblocks * BLCKSZ) < 0)
> return -1;
> + v->mdfd_lstbcnt = nblocks;
> + #endif
>
> return nblocks;
>

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