Vaccum Stalling

Version 7.4.12
AIX 5.3

Scenario - a large table was not being vacuumed correctly, there now ~
15 million dead tuples that account for approximately 20%-25% of the
table.  Vacuum appears to be stalling - ran for approximately 10 hours
before I killed it.  I hooked up to the process with gdb and this looks
a bit suspicious to me.

gdb attach 979354
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Attaching to process 979354
[Switching to Thread 1]
0xd033ce1c in read () from /usr/lib/libc.a(shr.o)
(gdb) bt
#0  0xd033ce1c in read () from /usr/lib/libc.a(shr.o)
#1  0x10034398 in FileRead (file=805585096, buffer=0xb38d0e40 "",
amount=8192) at fd.c:973
#2  0x1009eea8 in mdread (reln=0x301aa618, blocknum=160246,
buffer=0xb38d0e40 "") at md.c:434
#3  0x1009d3d0 in smgrread (which=8192, reln=0x301aa618,
blocknum=160246,
    buffer=0xffffffff <Address 0xffffffff out of bounds>) at smgr.c:316
#4  0x1002c0a8 in ReadBufferInternal (reln=0x301aa618, blockNum=160246,
bufferLockHeld=84 'T') at bufmgr.c:230
#5  0x101e5080 in _bt_getbuf (rel=0x301aa618, blkno=4294967295,
access=1) at nbtpage.c:401
#6  0x101e41c4 in btbulkdelete (fcinfo=0xffffffff) at nbtree.c:692
#7  0x10048670 in OidFunctionCall3 (functionId=8192, arg1=807052824,
arg2=805496980, arg3=806803160)
    at fmgr.c:1260
#8  0x100dad04 in index_bulk_delete (indexRelation=0x301aa618,
    callback=@0x3002e894: 0x10194150 <lazy_tid_reaped>,
callback_state=0x3016d6d8) at indexam.c:618
#9  0x10193fcc in lazy_vacuum_index (indrel=0x301aa618,
vacrelstats=0x3016d6d8) at vacuumlazy.c:712
#10 0x10194b04 in lazy_vacuum_rel (onerel=0x302357b8,
vacstmt=0xffffffff) at vacuumlazy.c:279
#11 0x10192da4 in vacuum_rel (relid=807622584, vacstmt=0x3016b558,
expected_relkind=114 'r') at vacuum.c:855
#12 0x10192fb0 in vacuum (vacstmt=0x3016b558) at vacuum.c:290
#13 0x10141670 in ProcessUtility (parsetree=0x3016b558,
dest=0x3016b5a8,
completionTag=0x2ff1d0c4 "")
    at utility.c:831
#14 0x10121b20 in PortalRunUtility (portal=0x301f3768,
query=0x3016b5f8,
dest=0x3016b5a8,
    completionTag=0x2ff1d0c4 "") at pquery.c:772
#15 0x1012204c in PortalRun (portal=0x301f3768, count=806794920,
dest=0x3016b5a8, altdest=0x3016b5a8,
    completionTag=0x2ff1d0c4 "") at pquery.c:836
#16 0x10010034 in exec_simple_query (query_string=0x3016b278 "VACUUM
ANALYZE v\erbos\e;") at postgres.c:914
---Type <return> to continue, or q <return> to quit---
#17 0x100119f8 in PostgresMain (argc=4, argv=0x30086e78,
username=0x30086db8 "slony") at postgres.c:2973
#18 0x101b79e4 in ServerLoop () at postmaster.c:2564
#19 0x101b95a0 in PostmasterMain (argc=1, argv=0x300853c8) at
postmaster.c:897
#20 0x1000053c in main (argc=1, argv=0x2ff22c40) at main.c:222
#21 0x10000204 in __start ()

Ideas?
--
Brad Nicholson  416-673-4106
Database Administrator, Afilias Canada Corp.