Re: 'COPY ... FROM' inserts to btree, blocks on buffer

On Fri, 31 Dec 2004, Tom Lane wrote:
> Michael Wildpaner <mike(at)rainbow(dot)studorg(dot)tuwien(dot)ac(dot)at> writes:
> > two concurrent clients try to 'COPY ... FROM ...' to the same table,
> > "feature_link".
>
> > The second one (pid 17983) is waiting for an ExclusiveLock on the table's
> > primary key index, "key__idpk__flink".
>
> You didn't show a stack trace for this one ...

Here it is:

[fuchs:/people/mike/build/postgresql-8.0.0beta2] gdb src/backend/postgres
[...]
(gdb) attach 17983
[...]
(gdb) where
#0 0x0000002a96181279 in semop () from /lib64/tls/libc.so.6
#1 0x0000000000511707 in PGSemaphoreLock (sema=0x2aa16d8f90, interruptOK=1 '\001') at pg_sema.c:418
#2 0x0000000000533e76 in ProcSleep (lockMethodTable=0x274801d, lockmode=7, lock=0x2aa1773878, proclock=0x2aa18ee398) at proc.c:725
#3 0x0000000000532a7c in WaitOnLock (lockmethodid=32797, locallock=0x894180, owner=0x975130) at lock.c:1037
#4 0x000000000053246f in LockAcquire (lockmethodid=1, locktag=0x1, xid=2710496152, lockmode=7, dontWait=0 '\0') at lock.c:754
#5 0x0000000000531aa3 in LockPage (relation=0x274801d, blkno=3220402448, lockmode=7) at lmgr.c:267
#6 0x000000000044a98d in _bt_getbuf (rel=0x2aa2466168, blkno=3220402448, access=2) at nbtpage.c:490
#7 0x0000000000448c87 in _bt_split (rel=0x2aa2466168, buf=16355, firstright=89, newitemoff=119, newitemsz=40, newitem=0x985828,
newitemonleft=0 '\0', itup_off=0x7fbff374c6, itup_blkno=0x7fbff374c8) at nbtinsert.c:683
#8 0x00000000004486ba in _bt_insertonpg (rel=0x2aa2466168, buf=16355, stack=0x9a2a70, keysz=1, scankey=0x984a60, btitem=0x985828,
afteritem=0, split_only_page=0 '\0') at nbtinsert.c:500
#9 0x00000000004481eb in _bt_doinsert (rel=0x2aa2466168, btitem=0x985828, index_is_unique=1 '\001', heapRel=0x2aa24656e8)
at nbtinsert.c:141
#10 0x000000000044bb71 in btinsert (fcinfo=0x274801d) at nbtree.c:257
#11 0x00000000005a44aa in OidFunctionCall6 (functionId=41189405, arg1=183111147880, arg2=548681250960, arg3=548681250928, arg4=10030788,
arg5=183111145192, arg6=18446744073709551612) at fmgr.c:1487
#12 0x00000000004476a5 in index_insert (indexRelation=0x2aa2466168, datums=0x7fbff37890, nulls=0x7fbff37870 " î", heap_t_ctid=0x990ec4,
heapRelation=0x2aa24656e8, check_uniqueness=1 '\001') at indexam.c:226
#13 0x00000000004cf3cf in ExecInsertIndexTuples (slot=0x0, tupleid=0x7fbff37110, estate=0x9828a0, is_vacuum=0 '\0') at execUtils.c:859
#14 0x000000000049c1d1 in CopyFrom (rel=0x2aa24656e8, attnumlist=0x9a25f0, binary=0 '\0', oids=0 '\0', delim=0x63e4cd "\t",
null_print=0x608614 "\\N", csv_mode=0 '\0', quote=0x0, escape=0x0, force_notnull_atts=0x9849d0) at copy.c:1958
#15 0x000000000049a34f in DoCopy (stmt=0x274801d) at copy.c:1043
#16 0x000000000053d7b9 in PortalRunUtility (portal=0x906b70, query=0x8fa620, dest=0x8fa940, completionTag=0x7fbff37f60 "") at pquery.c:839
#17 0x000000000053da41 in PortalRunMulti (portal=0x906b70, dest=0x8fa940, altdest=0x8fa940, completionTag=0x7fbff37f60 "") at pquery.c:902
#18 0x000000000053d230 in PortalRun (portal=0x906b70, count=9223372036854775807, dest=0x8fa940, altdest=0x8fa940,
completionTag=0x7fbff37f60 "") at pquery.c:543
#19 0x0000000000539c59 in exec_simple_query (
query_string=0x8fa730 "COPY feature_link from '/anniedev1/impseb/datastore/results/2004/12/29/22/38/bio:query:ncbi-blast:10562060.out_featurelink'") at postgres.c:924
#20 0x000000000053bf6d in PostgresMain (argc=9414448, argv=0x86f028, username=0x86eff0 "annieseb") at postgres.c:2970
#21 0x0000000000514db7 in BackendRun (port=0x89c650) at postmaster.c:2848
#22 0x0000000000514850 in BackendStartup (port=0x89c650) at postmaster.c:2470
#23 0x0000000000512fde in ServerLoop () at postmaster.c:1215
#24 0x0000000000512446 in PostmasterMain (argc=1, argv=0x804850) at postmaster.c:898
#25 0x00000000004e3206 in main (argc=1, argv=0x804850) at main.c:265

Happy new year! (nearly 2 AM MET here ;)
Best wishes, Mike

--
Do not feel safe. The poet remembers. DI Michael Wildpaner
You can kill one, but another is born. Ph.D. Student
The words are written down,
the deed, the date. (Czeslaw Milosz)