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BOUNCE pgsql-bugs@postgreSQL.org: Non-member submission from [Brent Ewing <bge@hoh.genome.washington.edu>]
owner-bugs@postgresql.org — 1999-10-02T23:21:38Z
>From scrappy@postgresql.org Sat Oct 2 19:19:16 1999 Received: from hoh.genome.washington.edu (hoh.genome.washington.edu [128.95.73.94]) by hub.org (8.9.3/8.9.3) with ESMTP id TAA28166 for <pgsql-bugs@postgresql.org>; Sat, 2 Oct 1999 19:18:45 -0400 (EDT) (envelope-from bge@hoh.genome.washington.edu) Received: (from bge@localhost) by hoh.genome.washington.edu (8.9.0/8.9.0) id QAA08813 for pgsql-bugs@postgresql.org; Sat, 2 Oct 1999 16:18:27 -0700 (PDT) Date: Sat, 2 Oct 1999 16:18:27 -0700 (PDT) From: Brent Ewing <bge@hoh.genome.washington.edu> Message-Id: <199910022318.QAA08813@hoh.genome.washington.edu> To: pgsql-bugs@postgresql.org Subject: possible bug If PostgreSQL failed to compile on your computer or you found a bug that is likely to be specific to one platform then please fill out this form and e-mail it to pgsql-ports@postgresql.org. To report any other bug, fill out the form below and e-mail it to pgsql-bugs@postgresql.org. If you not only found the problem but solved it and generated a patch then e-mail it to pgsql-patches@postgresql.org instead. Please use the command "diff -c" to generate the patch. You may also enter a bug report at http://www.postgresql.org/ instead of e-mail-ing this form. ============================================================================ POSTGRESQL BUG REPORT TEMPLATE ============================================================================ Your name : Brent Ewing Your email address : bge@u.washington.edu System Configuration --------------------- Architecture (example: Intel Pentium) : DEC Alpha Operating System (example: Linux 2.0.26 ELF) : Digital UNIX 4.0D PostgreSQL version (example: PostgreSQL-6.5.2): PostgreSQL-6.5.2 Compiler used (example: gcc 2.8.0) : mostly cc Please enter a FULL description of your problem: ------------------------------------------------ In short, the backend crashes while trying to create certain indexes on a table. I added some diagnostics in the modules nbtsort.c and bufpage.c where it's dying. The backend output is ------ hoh> postmaster -d FindExec: found "/usr/local/pgsql/bin/postgres" using argv[0] /usr/local/pgsql/bin/postmaster: BackendStartup: pid 26070 user bge db est_db socket 6 FindExec: found "/usr/local/pgsql/bin/postgres" using argv[0] started: host=localhost user=bge database=est_db InitPostgres StartTransactionCommand ProcessQuery CommitTransactionCommand StartTransactionCommand ProcessUtility PageAddItem: lower > upper: lower: 920 upper: 912: alignedSize: 32 pageManagerShuffle: 1 shuffled: 1 sizeof_itemiddata: 4 pd_lower: 916 pd_upper: 944 offsetNumber: 228 limit: 228 _bt_buildadd: alloc flag: 1 pgspc_old: 0 btisz_old: 32 PageGetFreeSpace: 24 FATAL 1: btree: failed to add item to the page in _bt_sort (2) proc_exit(0) [#0] shmem_exit(0) [#0] exit(0) /usr/local/pgsql/bin/postmaster: reaping dead processes... /usr/local/pgsql/bin/postmaster: CleanupProc: pid 26070 exited with status 0 ------ The problem occurs (is detected) in the function PageAddItem() (in bufpage.c) in the block that now looks like ------ if (offsetNumber > limit) lower = (Offset) (((char *) (&((PageHeader) page)->pd_linp[offsetNumber])) - ((char *) page)); else if (offsetNumber == limit || shuffled == true) lower = ((PageHeader) page)->pd_lower + sizeof(ItemIdData); else lower = ((PageHeader) page)->pd_lower; alignedSize = DOUBLEALIGN(size); upper = ((PageHeader) page)->pd_upper - alignedSize; if (lower > upper) { fprintf( stderr, "PageAddItem: lower > upper: lower: %d upper: %d: alignedSize: %d pageManagerShuffle: %d shuffled: %d sizeof_itemidd ata: %d pd_lower: %d pd_upper: %d offsetNumber: %d limit: %d\n", (int)lower, (int)upper, (int)alignedSize, (int)PageManagerShuffle, shuffled, sizeof( ItemIdData ), (int)((PageHeader) page)->pd_lower, (int)((PageHeader) page)->pd_upper, offsetNumber, limit ); return InvalidOffsetNumber; } ------ The problem is that lower > upper! The bit of output from the calling function, _bt_buildadd in nbtsort.c, shows the values of pgspc and btisz near the start of the function. The code and my additions at this point are ------ nbuf = state->btps_buf; npage = state->btps_page; first_off = state->btps_firstoff; last_off = state->btps_lastoff; last_bti = state->btps_lastbti; pgspc = PageGetFreeSpace(npage); btisz = BTITEMSZ(bti); btisz = MAXALIGN(btisz); if (pgspc < btisz) { Buffer obuf = nbuf; Page opage = npage; OffsetNumber o, n; ItemId ii; ItemId hii; pgspc_sav = pgspc; btisz_sav = btisz; _bt_blnewpage(index, &nbuf, &npage, flags); alloc_spc_flag = 1; ------ nd the code and my additions at the point where PageAddItem is called and returns failure looks like ------ /* * if this item is different from the last item added, we start a new * chain of duplicates. */ off = OffsetNumberNext(last_off); if (PageAddItem(npage, (Item) bti, btisz, off, LP_USED) == InvalidOffsetNumber) { fprintf( stderr, "_bt_buildadd: alloc flag: %d pgspc_old: %d btisz_old: %d PageGetFreeSpace: %d\n", alloc_spc_flag, pgspc_sav, btisz_s av, (int)PageGetFreeSpace(npage) ); elog(FATAL, "btree: failed to add item to the page in _bt_sort (2)"); } #ifdef NOT_USED #if defined(FASTBUILD_DEBUG) && defined(FASTBUILD_MERGE) { bool isnull; Datum d = index_getattr(&(bti->bti_itup), 1, index->rd_att, &isnull); printf("_bt_buildadd: inserted <%x> at offset %d at level %d\n", d, off, state->btps_level); } #endif /* FASTBUILD_DEBUG && FASTBUILD_MERGE */ #endif ------ Incidentally, I vacuumed several times, without affecting the outcome. Also, the problem surfaced as I ran PG v6.5. I subsequently installed v6.5.2 without modifying the database, and tried again with the same result. Please describe a way to repeat the problem. Please try to provide a concise reproducible example, if at all possible: ---------------------------------------------------------------------- I can repeat this on my data set, perfectly consistently. If this is really a bug, I can add diagnostic code where ever you would like it added. (The data set is over a Gbyte so it is not easily sent.) If you know how this problem might be fixed, list the solution below: ---------------------------------------------------------------------