Query Hangs while Parsing

Question

In one of our databases, one of the Select query hangs at the parsing stage. The query was working fine few days back. How and what can be traced to see the cause of this hang. Database is in 10.2.0.3 and statistics has been gathered for all the affected tables.

Answer 1

Thanks for the info. The SEQ# is not changing in the v$session_waits. I have found a workaround for this problem. If I delete the statistics for CS_MEASUREMENT table, the query gets executed in .35 secs! If i collect stats again and runs, it hangs.
The session trace below.
TKPROF: Release 10.2.0.3.0 - Production on Fri May 30 11:43:02 2008
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Trace file: css1cldr_ora_10134.trc
Sort options: default
count = number of times OCI procedure was executed
cpu = cpu time in seconds executing
elapsed = elapsed time in seconds executing
disk = number of physical reads of buffers from disk
query = number of buffers gotten for consistent read
current = number of buffers gotten in current mode (usually for update)
rows = number of rows processed by the fetch or execute call
select i.obj#,i.ts#,i.file#,i.block#,i.intcols,i.type#,i.flags,i.property,
i.pctfree$,i.initrans,i.maxtrans,i.blevel,i.leafcnt,i.distkey,i.lblkkey,
i.dblkkey,i.clufac,i.cols,i.analyzetime,i.samplesize,i.dataobj#,
nvl(i.degree,1),nvl(i.instances,1),i.rowcnt,mod(i.pctthres$,256),
i.indmethod#,i.trunccnt,nvl(c.unicols,0),nvl(c.deferrable#+c.valid#,0),
nvl(i.spare1,i.intcols),i.spare4,i.spare2,i.spare6,decode(i.pctthres$,null,
null,mod(trunc(i.pctthres$/256),256)),ist.cachedblk,ist.cachehit,
ist.logicalread
from
ind$ i, ind_stats$ ist, (select enabled, min(cols) unicols,
min(to_number(bitand(defer,1))) deferrable#,min(to_number(bitand(defer,4)))
valid# from cdef$ where obj#=:1 and enabled > 1 group by enabled) c where
i.obj#=c.enabled(+) and i.obj# = ist.obj#(+) and i.bo#=:1 order by i.obj#
call count cpu elapsed disk query current rows
Parse 1 0.01 0.00 0 0 0 0
Execute 3 0.01 0.01 0 0 0 0
Fetch 10 0.00 0.00 0 33 0 7
total 14 0.02 0.02 0 33 0 7
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
2 SORT ORDER BY (cr=10 pr=0 pw=0 time=2852 us)
2 HASH JOIN OUTER (cr=10 pr=0 pw=0 time=2741 us)
2 NESTED LOOPS OUTER (cr=7 pr=0 pw=0 time=102 us)
2 TABLE ACCESS CLUSTER IND$ (cr=5 pr=0 pw=0 time=73 us)
1 INDEX UNIQUE SCAN I_OBJ# (cr=2 pr=0 pw=0 time=29 us)(object id 3)
0 TABLE ACCESS BY INDEX ROWID IND_STATS$ (cr=2 pr=0 pw=0 time=22 us)
0 INDEX UNIQUE SCAN I_IND_STATS$_OBJ# (cr=2 pr=0 pw=0 time=18 us)(object id 711)
2 VIEW (cr=3 pr=0 pw=0 time=361 us)
2 SORT GROUP BY (cr=3 pr=0 pw=0 time=356 us)
2 TABLE ACCESS CLUSTER CDEF$ (cr=3 pr=0 pw=0 time=58 us)
1 INDEX UNIQUE SCAN I_COBJ# (cr=2 pr=0 pw=0 time=25 us)(object id 30)
select /*+ rule */ bucket_cnt, row_cnt, cache_cnt, null_cnt, timestamp#,
sample_size, minimum, maximum, distcnt, lowval, hival, density, col#,
spare1, spare2, avgcln
from
hist_head$ where obj#=:1 and intcol#=:2
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 50 0.01 0.00 0 0 0 0
Fetch 50 0.00 0.00 0 150 0 50
total 101 0.01 0.01 0 150 0 50
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: RULE
Parsing user id: SYS (recursive depth: 2)
Rows Row Source Operation
1 TABLE ACCESS BY INDEX ROWID HIST_HEAD$ (cr=3 pr=0 pw=0 time=81 us)
1 INDEX RANGE SCAN I_HH_OBJ#_INTCOL# (cr=2 pr=0 pw=0 time=57 us)(object id 257)
select /*+ rule */ bucket, endpoint, col#, epvalue
from
histgrm$ where obj#=:1 and intcol#=:2 and row#=:3 order by bucket
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 60 0.03 0.01 0 0 0 0
Fetch 60 0.01 0.00 0 206 0 973
total 121 0.04 0.02 0 206 0 973
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: RULE
Parsing user id: SYS (recursive depth: 2)
Rows Row Source Operation
3 SORT ORDER BY (cr=3 pr=0 pw=0 time=130 us)
3 TABLE ACCESS CLUSTER HISTGRM$ (cr=3 pr=0 pw=0 time=66 us)
1 INDEX UNIQUE SCAN I_OBJ#_INTCOL# (cr=2 pr=0 pw=0 time=27 us)(object id 252)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 1 0.00 0.00
SQL*Net message from client 1 10.13 10.13
select pos#,intcol#,col#,spare1,bo#,spare2
from
icol$ where obj#=:1
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 7 0.01 0.00 0 0 0 0
Fetch 25 0.00 0.00 0 50 0 18
total 33 0.01 0.00 0 50 0 18
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
2 TABLE ACCESS BY INDEX ROWID ICOL$ (cr=6 pr=0 pw=0 time=36 us)
2 INDEX RANGE SCAN I_ICOL1 (cr=4 pr=0 pw=0 time=38 us)(object id 40)
select name,intcol#,segcol#,type#,length,nvl(precision#,0),decode(type#,2,
nvl(scale,-127/*MAXSB1MINAL*/),178,scale,179,scale,180,scale,181,scale,182,
scale,183,scale,231,scale,0),null$,fixedstorage,nvl(deflength,0),default$,
rowid,col#,property, nvl(charsetid,0),nvl(charsetform,0),spare1,spare2,
nvl(spare3,0)
from
col$ where obj#=:1 order by intcol#
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 3 0.00 0.01 0 0 0 0
Fetch 87 0.00 0.00 0 11 0 84
total 91 0.00 0.01 0 11 0 84
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
12 SORT ORDER BY (cr=3 pr=0 pw=0 time=157 us)
12 TABLE ACCESS CLUSTER COL$ (cr=3 pr=0 pw=0 time=79 us)
1 INDEX UNIQUE SCAN I_OBJ# (cr=2 pr=0 pw=0 time=24 us)(object id 3)
select col#, grantee#, privilege#,max(mod(nvl(option$,0),2))
from
objauth$ where obj#=:1 and col# is not null group by privilege#, col#,
grantee# order by col#, grantee#
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 3 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 0 6 0 0
total 7 0.00 0.00 0 6 0 0
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
0 SORT GROUP BY (cr=2 pr=0 pw=0 time=57 us)
0 TABLE ACCESS BY INDEX ROWID OBJAUTH$ (cr=2 pr=0 pw=0 time=34 us)
0 INDEX RANGE SCAN I_OBJAUTH1 (cr=2 pr=0 pw=0 time=31 us)(object id 103)
select grantee#,privilege#,nvl(col#,0),max(mod(nvl(option$,0),2))
from
objauth$ where obj#=:1 group by grantee#,privilege#,nvl(col#,0) order by
grantee#
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 3 0.00 0.00 0 0 0 0
Fetch 18 0.00 0.00 0 12 0 15
total 22 0.00 0.00 0 12 0 15
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
5 SORT GROUP BY (cr=4 pr=0 pw=0 time=107 us)
5 TABLE ACCESS BY INDEX ROWID OBJAUTH$ (cr=4 pr=0 pw=0 time=43 us)
5 INDEX RANGE SCAN I_OBJAUTH1 (cr=2 pr=0 pw=0 time=16 us)(object id 103)
select con#,obj#,rcon#,enabled,nvl(defer,0)
from
cdef$ where robj#=:1
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 3 0.01 0.00 0 0 0 0
Fetch 3 0.00 0.00 0 3 0 0
total 7 0.01 0.00 0 3 0 0
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
0 TABLE ACCESS BY INDEX ROWID CDEF$ (cr=1 pr=0 pw=0 time=22 us)
0 INDEX RANGE SCAN I_CDEF3 (cr=1 pr=0 pw=0 time=20 us)(object id 52)
select con#,type#,condlength,intcols,robj#,rcon#,match#,refact,nvl(enabled,0),
rowid,cols,nvl(defer,0),mtime,nvl(spare1,0)
from
cdef$ where obj#=:1
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 3 0.00 0.00 0 0 0 0
Fetch 34 0.00 0.00 0 42 0 31
total 38 0.00 0.00 0 42 0 31
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
5 TABLE ACCESS CLUSTER CDEF$ (cr=9 pr=0 pw=0 time=17 us)
1 INDEX UNIQUE SCAN I_COBJ# (cr=2 pr=0 pw=0 time=10 us)(object id 30)
select intcol#,nvl(pos#,0),col#,nvl(spare1,0)
from
ccol$ where con#=:1
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 31 0.01 0.00 0 0 0 0
Fetch 70 0.00 0.00 0 140 0 39
total 102 0.01 0.00 0 140 0 39
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
2 TABLE ACCESS BY INDEX ROWID CCOL$ (cr=6 pr=0 pw=0 time=49 us)
2 INDEX RANGE SCAN I_CCOL1 (cr=4 pr=0 pw=0 time=45 us)(object id 54)
select condition
from
cdef$ where rowid=:1
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 0.00 0.00 0 2 0 1
total 3 0.00 0.00 0 2 0 1
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Rows Row Source Operation
1 TABLE ACCESS BY USER ROWID CDEF$ (cr=1 pr=0 pw=0 time=18 us)
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 0 0.00 0.00 0 0 0 0
Execute 0 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
total 0 0.00 0.00 0 0 0 0
Misses in library cache during parse: 0
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 1 0.00 0.00
SQL*Net message from client 1 10.13 10.13
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 11 0.01 0.01 0 0 0 0
Execute 167 0.08 0.07 0 0 0 0
Fetch 361 0.01 0.01 0 655 0 1218
total 539 0.10 0.10 0 655 0 1218
Misses in library cache during parse: 10
Misses in library cache during execute: 10
0 user SQL statements in session.
167 internal SQL statements in session.
167 SQL statements in session.
Trace file: css1cldr_ora_10134.trc
Trace file compatibility: 10.01.00
Sort options: default
1 session in tracefile.
0 user SQL statements in trace file.
167 internal SQL statements in trace file.
167 SQL statements in trace file.
11 unique SQL statements in trace file.
3548 lines in trace file.
0 elapsed seconds in trace file.