Select count(*) from table in oracle 11g with direct path read takes time
select count(*) from table takes long time, even more than couple of hours..
direct path read is the wait event which is almost is at 99%..
can u someone provide some info on this.. on solution.. thankx
knowledgespring wrote:
table has millions of records... 130 millions..
select count(*) from BIG_SIZE_TABLE; --- executed in sql plus command prompt.
Rows Execution Plan
0 SELECT STATEMENT MODE: ALL_ROWS
0 SORT (AGGREGATE)
0 TABLE ACCESS MODE: ANALYZED (FULL) OF 'BIG_SIZE_TABLE' (TABLE)
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
enq: KO - fast object checkpoint 1 0.01 0.01
Disk file operations I/O 18 0.00 0.00
direct path read 58921 0.34 418.54direct path read time waited is : 58921 total time waited: 418.54
That 418 seconds - not the hours you reported earlier. Is it possible that your connection to the database broke ?
On a typical system, by the way, you can usually turn one direct read for tablescan into 1MB, so your scan seems to have covered about 59 GB, which seems to be in the right sort of ballpark for 130M rows.
we have another query and when we test the query execution using v$sql, is_bind_sensitive =N, how to make is_bind_sensitive=Y all the time.. There is a hint /*+ bind_aware */ - I'd have to check whether or not it's documented at present. It might help.
I would be interested in hearing why you think the hint should be bind sensitive when the optimizer doesn't.
Regards
Jonathan Lewis
Similar Messages
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How do I execute "Select count(*) from table " in OCI
Hi,
I am new to OCI and so this question may seem stupid. I would like to know how to execute the query "select count(*) from <table>" using OCI V8 functionality? Also after how do I get the result into a integer datatype? I have gone through most of the demo programs but is is of little help to me.
Thanks in advance...
Regards,
Shubhayan.Hi,
Here is sample code to give you some idea how to do it. If you want some more info let me know.
Pankaj
ub4 count;
// Prepare the statement.
char szQry = "SELECT count() FROM T1";
if(OCI_ERROR == OCIStmtPrepare(pStmthp, pErrhp, (unsigned char*)szQry, strlen(szQry), OCI_NTV_SYNTAX , OCI_DEFAULT) )
cout << "Error in OCIStmtPrepare" << endl;
exit(1);
// Bind the output parameter.
OCIDefine *pDefnpp;
if(OCI_ERROR == OCIDefineByPos ( pStmthp, &pDefnpp, pErrhp, 1,
&count, sizeof(ub4), SQLT_INT,
(dvoid *) 0, (ub2 *) 0, (ub2 *) 0,
OCI_DEFAULT) )
cout << "Error in OCIDefineByPos" << endl;
exit(1);
if(OCI_ERROR == OCIStmtExecute(pSvchp, pStmthp, pErrhp, 1, 0, NULL, NULL, OCI_DEFAULT) )
cout << "Error in OCIStmtExecute" << endl;
exit(1); -
Serial table scan with direct path read compared to db file scattered read
Hi,
The environment
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit
8K block size
db_file_multiblock_read_count is 128
show sga
Total System Global Area 1.6702E+10 bytes
Fixed Size 2219952 bytes
Variable Size 7918846032 bytes
Database Buffers 8724152320 bytes
Redo Buffers 57090048 bytes
16GB of SGA with 8GB of db buffer cache.
-- database is built on Solid State Disks
-- SQL trace and wait events
DBMS_MONITOR.SESSION_TRACE_ENABLE ( waits=>true )
-- The underlying table is called tdash. It has 1.7 Million rows based on data in all_objects. NO index
TABLE_NAME Rows Table Size/MB Used/MB Free/MB
TDASH 1,729,204 15,242 15,186 56
TABLE_NAME Allocated blocks Empty blocks Average space/KB Free list blocks
TDASH 1,943,823 7,153 805 0
Objectives
To show that when serial scans are performed on database built on Solid State Disks (SSD) compared to Magnetic disks (HDD), the performance gain is far less compared to random reads with index scans on SSD compared to HDD
Approach
We want to read the first 100 rows of tdash table randomly into buffer, taking account of wait events and wait times generated. The idea is that on SSD the wait times will be better compared to HDD but not that much given the serial nature of table scans.
The code used
ALTER SESSION SET TRACEFILE_IDENTIFIER = 'test_with_tdash_ssdtester_noindex';
DECLARE
type array is table of tdash%ROWTYPE index by binary_integer;
l_data array;
l_rec tdash%rowtype;
BEGIN
SELECT
a.*
,RPAD('*',4000,'*') AS PADDING1
,RPAD('*',4000,'*') AS PADDING2
BULK COLLECT INTO
l_data
FROM ALL_OBJECTS a;
DBMS_MONITOR.SESSION_TRACE_ENABLE ( waits=>true );
FOR rs IN 1 .. 100
LOOP
BEGIN
SELECT * INTO l_rec FROM tdash WHERE object_id = l_data(rs).object_id;
EXCEPTION
WHEN NO_DATA_FOUND THEN NULL;
END;
END LOOP;
END;
/Server is rebooted prior to any tests
Whern run as default, the optimizer (although some attribute this to the execution engine) chooses direct path read into PGA in preference to db file scattered read.
With this choice it takes 6,520 seconds to complete the query. The results are shown below
SQL ID: 78kxqdhk1ubvq
Plan Hash: 1148949653
SELECT *
FROM
TDASH WHERE OBJECT_ID = :B1
call count cpu elapsed disk query current rows
Parse 1 0.01 0.00 2 47 0 0
Execute 100 0.00 0.00 1 51 0 0
Fetch 100 10.88 6519.89 194142802 194831012 0 100
total 201 10.90 6519.90 194142805 194831110 0 100
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 96 (SSDTESTER) (recursive depth: 1)
Rows Row Source Operation
1 TABLE ACCESS FULL TDASH (cr=1948310 pr=1941430 pw=0 time=0 us cost=526908 size=8091 card=1)
Rows Execution Plan
0 SELECT STATEMENT MODE: ALL_ROWS
1 TABLE ACCESS MODE: ANALYZED (FULL) OF 'TDASH' (TABLE)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
Disk file operations I/O 3 0.00 0.00
db file sequential read 2 0.00 0.00
direct path read 1517504 0.05 6199.93
asynch descriptor resize 196 0.00 0.00
DECLARE
type array is table of tdash%ROWTYPE index by binary_integer;
l_data array;
l_rec tdash%rowtype;
BEGIN
SELECT
a.*
,RPAD('*',4000,'*') AS PADDING1
,RPAD('*',4000,'*') AS PADDING2
BULK COLLECT INTO
l_data
FROM ALL_OBJECTS a;
DBMS_MONITOR.SESSION_TRACE_ENABLE ( waits=>true );
FOR rs IN 1 .. 100
LOOP
BEGIN
SELECT * INTO l_rec FROM tdash WHERE object_id = l_data(rs).object_id;
EXCEPTION
WHEN NO_DATA_FOUND THEN NULL;
END;
END LOOP;
END;
call count cpu elapsed disk query current rows
Parse 0 0.00 0.00 0 0 0 0
Execute 1 3.84 4.03 320 48666 0 1
Fetch 0 0.00 0.00 0 0 0 0
total 1 3.84 4.03 320 48666 0 1
Misses in library cache during parse: 0
Misses in library cache during execute: 1
Optimizer mode: ALL_ROWS
Parsing user id: 96 (SSDTESTER)
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 0.00 0.00
SQL ID: 9babjv8yq8ru3
Plan Hash: 0
BEGIN DBMS_OUTPUT.GET_LINES(:LINES, :NUMLINES); END;
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 1
Fetch 0 0.00 0.00 0 0 0 0
total 2 0.00 0.00 0 0 0 1
Misses in library cache during parse: 0
Optimizer mode: ALL_ROWS
Parsing user id: 96 (SSDTESTER)
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 0.00 0.00
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 2 3.84 4.03 320 48666 0 2
Fetch 0 0.00 0.00 0 0 0 0
total 3 3.84 4.03 320 48666 0 2
Misses in library cache during parse: 0
Misses in library cache during execute: 1
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 2 0.00 0.00
SQL*Net message from client 2 0.00 0.00
log file sync 1 0.00 0.00
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 9 0.01 0.00 2 47 0 0
Execute 129 0.01 0.00 1 52 2 1
Fetch 140 10.88 6519.89 194142805 194831110 0 130
total 278 10.91 6519.91 194142808 194831209 2 131
Misses in library cache during parse: 9
Misses in library cache during execute: 8
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
db file sequential read 5 0.00 0.00
Disk file operations I/O 3 0.00 0.00
direct path read 1517504 0.05 6199.93
asynch descriptor resize 196 0.00 0.00
102 user SQL statements in session.
29 internal SQL statements in session.
131 SQL statements in session.
1 statement EXPLAINed in this session.
Trace file: mydb_ora_16394_test_with_tdash_ssdtester_noindex.trc
Trace file compatibility: 11.1.0.7
Sort options: default
1 session in tracefile.
102 user SQL statements in trace file.
29 internal SQL statements in trace file.
131 SQL statements in trace file.
11 unique SQL statements in trace file.
1 SQL statements EXPLAINed using schema:
ssdtester.plan_table
Schema was specified.
Table was created.
Table was dropped.
1531657 lines in trace file.
6520 elapsed seconds in trace file.I then force the query not to use direct path read by invoking
ALTER SESSION SET EVENTS '10949 trace name context forever, level 1' -- No Direct path read ;In this case the optimizer uses db file scattered read predominantly and the query takes 4,299 seconds to finish which is around 34% faster than using direct path read (default).
The report is shown below
SQL ID: 78kxqdhk1ubvq
Plan Hash: 1148949653
SELECT *
FROM
TDASH WHERE OBJECT_ID = :B1
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 2 47 0 0
Execute 100 0.00 0.00 2 51 0 0
Fetch 100 143.44 4298.87 110348670 194490912 0 100
total 201 143.45 4298.88 110348674 194491010 0 100
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 96 (SSDTESTER) (recursive depth: 1)
Rows Row Source Operation
1 TABLE ACCESS FULL TDASH (cr=1944909 pr=1941430 pw=0 time=0 us cost=526908 size=8091 card=1)
Rows Execution Plan
0 SELECT STATEMENT MODE: ALL_ROWS
1 TABLE ACCESS MODE: ANALYZED (FULL) OF 'TDASH' (TABLE)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
Disk file operations I/O 3 0.00 0.00
db file sequential read 129759 0.01 17.50
db file scattered read 1218651 0.05 3770.02
latch: object queue header operation 2 0.00 0.00
DECLARE
type array is table of tdash%ROWTYPE index by binary_integer;
l_data array;
l_rec tdash%rowtype;
BEGIN
SELECT
a.*
,RPAD('*',4000,'*') AS PADDING1
,RPAD('*',4000,'*') AS PADDING2
BULK COLLECT INTO
l_data
FROM ALL_OBJECTS a;
DBMS_MONITOR.SESSION_TRACE_ENABLE ( waits=>true );
FOR rs IN 1 .. 100
LOOP
BEGIN
SELECT * INTO l_rec FROM tdash WHERE object_id = l_data(rs).object_id;
EXCEPTION
WHEN NO_DATA_FOUND THEN NULL;
END;
END LOOP;
END;
call count cpu elapsed disk query current rows
Parse 0 0.00 0.00 0 0 0 0
Execute 1 3.92 4.07 319 48625 0 1
Fetch 0 0.00 0.00 0 0 0 0
total 1 3.92 4.07 319 48625 0 1
Misses in library cache during parse: 0
Misses in library cache during execute: 1
Optimizer mode: ALL_ROWS
Parsing user id: 96 (SSDTESTER)
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 0.00 0.00
SQL ID: 9babjv8yq8ru3
Plan Hash: 0
BEGIN DBMS_OUTPUT.GET_LINES(:LINES, :NUMLINES); END;
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 1
Fetch 0 0.00 0.00 0 0 0 0
total 2 0.00 0.00 0 0 0 1
Misses in library cache during parse: 0
Optimizer mode: ALL_ROWS
Parsing user id: 96 (SSDTESTER)
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 0.00 0.00
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 2 3.92 4.07 319 48625 0 2
Fetch 0 0.00 0.00 0 0 0 0
total 3 3.92 4.07 319 48625 0 2
Misses in library cache during parse: 0
Misses in library cache during execute: 1
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 2 0.00 0.00
SQL*Net message from client 2 0.00 0.00
log file sync 1 0.00 0.00
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 9 0.01 0.00 2 47 0 0
Execute 129 0.00 0.00 2 52 2 1
Fetch 140 143.44 4298.87 110348674 194491010 0 130
total 278 143.46 4298.88 110348678 194491109 2 131
Misses in library cache during parse: 9
Misses in library cache during execute: 8
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
db file sequential read 129763 0.01 17.50
Disk file operations I/O 3 0.00 0.00
db file scattered read 1218651 0.05 3770.02
latch: object queue header operation 2 0.00 0.00
102 user SQL statements in session.
29 internal SQL statements in session.
131 SQL statements in session.
1 statement EXPLAINed in this session.
Trace file: mydb_ora_26796_test_with_tdash_ssdtester_noindex_NDPR.trc
Trace file compatibility: 11.1.0.7
Sort options: default
1 session in tracefile.
102 user SQL statements in trace file.
29 internal SQL statements in trace file.
131 SQL statements in trace file.
11 unique SQL statements in trace file.
1 SQL statements EXPLAINed using schema:
ssdtester.plan_table
Schema was specified.
Table was created.
Table was dropped.
1357958 lines in trace file.
4299 elapsed seconds in trace file.I note that there are 1,517,504 waits with direct path read with total time of nearly 6,200 seconds. In comparison with no direct path read, there are 1,218,651 db file scattered read waits with total wait time of 3,770 seconds. My understanding is that direct path read can use single or multi-block read into the PGA. However db file scattered reads do multi-block read into multiple discontinuous SGA buffers. So it is possible given the higher number of direct path waits that the optimizer cannot do multi-block reads (contigious buffers within PGA) and hence has to revert to single blocks reads which results in more calls and more waits?.
Appreciate any advise and apologies for being long winded.
Thanks,
MichHi Charles,
I am doing your tests for t1 table using my server.
Just to clarify my environment is:
I did the whole of this test on my server. My server has I7-980 HEX core processor with 24GB of RAM and 1 TB of HDD SATA II for test/scratch backup and archive. The operating system is RHES 5.2 64-bit installed on a 120GB OCZ Vertex 3 Series SATA III 2.5-inch Solid State Drive.
Oracle version installed was 11g Enterprise Edition Release 11.2.0.1.0 -64bit. The binaries were created on HDD. Oracle itself was configured with 16GB of SGA, of which 7.5GB was allocated to Variable Size and 8GB to Database Buffers.
For Oracle tablespaces including SYS, SYSTEM, SYSAUX, TEMPORARY, UNDO and redo logs, I used file systems on 240GB OCZ Vertex 3 Series SATA III 2.5-inch Solid State Drive. With 4K Random Read at 53,500 IOPS and 4K Random Write at 56,000 IOPS (manufacturer’s figures), this drive is probably one of the fastest commodity SSDs using NAND flash memory with Multi-Level Cell (MLC). Now my T1 table created as per your script and has the following rows and blocks (8k block size)
SELECT
NUM_ROWS,
BLOCKS
FROM
USER_TABLES
WHERE
TABLE_NAME='T1';
NUM_ROWS BLOCKS
12000000 178952which is pretty identical to yours.
Then I run the query as brelow
set timing on
ALTER SESSION SET TRACEFILE_IDENTIFIER = 'test_bed_T1';
ALTER SESSION SET EVENTS '10046 TRACE NAME CONTEXT FOREVER, LEVEL 8';
SELECT
COUNT(*)
FROM
T1
WHERE
RN=1;
which gives
COUNT(*)
60000
Elapsed: 00:00:05.29
tkprof output shows
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 2 0.02 5.28 178292 178299 0 1
total 4 0.02 5.28 178292 178299 0 1
Compared to yours:
Fetch 2 0.60 4.10 178493 178498 0 1
It appears to me that my CPU utilisation is by order of magnitude better but my elapsed time is worse!
Now the way I see it elapsed time = CPU time + wait time. Further down I have
Rows Row Source Operation
1 SORT AGGREGATE (cr=178299 pr=178292 pw=0 time=0 us)
60000 TABLE ACCESS FULL T1 (cr=178299 pr=178292 pw=0 time=42216 us cost=48697 size=240000 card=60000)
Rows Execution Plan
0 SELECT STATEMENT MODE: ALL_ROWS
1 SORT (AGGREGATE)
60000 TABLE ACCESS MODE: ANALYZED (FULL) OF 'T1' (TABLE)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 3 0.00 0.00
SQL*Net message from client 3 0.00 0.00
Disk file operations I/O 3 0.00 0.00
direct path read 1405 0.00 4.68
Your direct path reads are
direct path read 1404 0.01 3.40Which indicates to me you have faster disks compared to mine, whereas it sounds like my CPU is faster than yours.
With db file scattered read I get
Elapsed: 00:00:06.95
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 2 1.22 6.93 178293 178315 0 1
total 4 1.22 6.94 178293 178315 0 1
Rows Row Source Operation
1 SORT AGGREGATE (cr=178315 pr=178293 pw=0 time=0 us)
60000 TABLE ACCESS FULL T1 (cr=178315 pr=178293 pw=0 time=41832 us cost=48697 size=240000 card=60000)
Rows Execution Plan
0 SELECT STATEMENT MODE: ALL_ROWS
1 SORT (AGGREGATE)
60000 TABLE ACCESS MODE: ANALYZED (FULL) OF 'T1' (TABLE)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 2 0.00 0.00
Disk file operations I/O 3 0.00 0.00
db file sequential read 1 0.00 0.00
db file scattered read 1414 0.00 5.36
SQL*Net message from client 2 0.00 0.00
compared to your
db file scattered read 1415 0.00 4.16On the face of it with this test mine shows 21% improvement with direct path read compared to db scattered file read. So now I can go back to re-visit my original test results:
First default with direct path read
call count cpu elapsed disk query current rows
Parse 1 0.01 0.00 2 47 0 0
Execute 100 0.00 0.00 1 51 0 0
Fetch 100 10.88 6519.89 194142802 194831012 0 100
total 201 10.90 6519.90 194142805 194831110 0 100
CPU ~ 11 sec, elapsed ~ 6520 sec
wait stats
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
direct path read 1517504 0.05 6199.93
roughly 0.004 sec for each I/ONow with db scattered file read I get
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 2 47 0 0
Execute 100 0.00 0.00 2 51 0 0
Fetch 100 143.44 4298.87 110348670 194490912 0 100
total 201 143.45 4298.88 110348674 194491010 0 100
CPU ~ 143 sec, elapsed ~ 4299 sec
and waits:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
db file sequential read 129759 0.01 17.50
db file scattered read 1218651 0.05 3770.02
roughly 17.5/129759 = .00013 sec for single block I/O and 3770.02/1218651 = .0030 for multi-block I/ONow my theory is that the improvements comes from the large buffer cache (8320MB) inducing it to do some read aheads (async pre-fetch). Read aheads are like quasi logical I/Os and they will be cheaper compared to physical I/O. When there is large buffer cache and read aheads can be done then using buffer cache is a better choice than PGA?
Regards,
Mich -
Select count from large fact tables with bitmap indexes on them
Hi..
I have several large fact tables with bitmap indexes on them, and when I do a select count from these tables, I get a different result than when I do a select count, column one from the table, group by column one. I don't have any null values in these columns. Is there a patch or a one-off that can rectify this.
ThxYou may have corruption in the index if the queries ...
Select /*+ full(t) */ count(*) from my_table t
... and ...
Select /*+ index_combine(t my_index) */ count(*) from my_table t;
... give different results.
Look at metalink for patches, and in the meantime drop-and-recreate the indexes or make them unusable then rebuild them. -
"select count(*) from dba_jobs_running" takes 5 minutes to return
Hi,
I login as sys or system from sql*plus to run query "select count(*) from dba_jobs_running". This query takes about 5 minutes to run.
Querying other DBA_* views returns instantly, only this dba_jobs_running view is troubling.
I have 11 records in dba_jobs, and 18 records in v$lock as usual.
No error or warning in logfile, no trace file.
What's possibly wrong with the server?
Thanks,
HarryHi,
The following are the exact statements I used to create the trace file:
alter session set timed_statistics=true;
alter session set max_dump_file_size=unlimited;
alter session set events '10046 trace name context forever, level 12';
select count(*) from dba_jobs_running;
exit;
The content of the trace file is attached at the end.
If it is CPU bound, I have no activity on the db host. I am solely using it to analyze this problem.
load averages: 0.02, 0.02, 0.07 22:16:38
48 processes: 47 sleeping, 1 on cpu
CPU states: 98.4% idle, 1.6% user, 0.0% kernel, 0.0% iowait, 0.0% swap
Memory: 1792M real, 983M free, 517M swap in use, 2937M swap free
PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND
655 oracle 1 59 0 0K 0K sleep 1:14 0.32% oracle
865 oracle 1 59 0 2072K 1184K cpu 0:00 0.14% top
667 oracle 1 59 0 0K 0K sleep 0:13 0.08% oracle
663 oracle 1 59 0 0K 0K sleep 0:27 0.07% oracle
665 oracle 1 59 0 0K 0K sleep 0:15 0.02% oracle
671 oracle 1 59 0 0K 0K sleep 0:00 0.02% oracle
645 oracle 18 59 0 0K 0K sleep 0:23 0.01% oracle
657 oracle 1 59 0 0K 0K sleep 0:14 0.00% oracle
649 oracle 1 59 0 0K 0K sleep 0:02 0.00% oracle
659 oracle 1 59 0 0K 0K sleep 0:01 0.00% oracle
251 root 20 59 0 3256K 2512K sleep 0:00 0.00% nscd
70 root 5 59 0 2864K 2096K sleep 0:00 0.00% picld
224 root 3 59 0 3912K 2008K sleep 0:00 0.00% automountd
271 root 1 59 0 4408K 1896K sleep 0:00 0.00% sendmail
588 oracle 1 59 0 2600K 1864K sleep 0:00 0.00% bash
Any help is greatly appreciated.
<-- TRACE FILE CONTENT -->
*** 2006-11-21 21:34:54.413
*** SESSION ID:(21.832) 2006-11-21 21:34:54.412
APPNAME mod='[email protected] (TNS V1-V3)' mh=0 act='' ah=0
=====================
PARSING IN CURSOR #1 len=69 dep=0 uid=0 oct=42 lid=0 tim=107123626140 hv=2004533713 ad='97219d80'
alter session set events '10046 trace name context forever, level 12'
END OF STMT
EXEC #1:c=0,e=346,p=0,cr=0,cu=0,mis=1,r=0,dep=0,og=4,tim=107123625473
WAIT #1: nam='SQL*Net message to client' ela= 11 p1=1650815232 p2=1 p3=0
WAIT #1: nam='SQL*Net message from client' ela= 6476024 p1=1650815232 p2=1 p3=0
=====================
PARSING IN CURSOR #1 len=37 dep=0 uid=0 oct=3 lid=0 tim=107130104260 hv=2246554324 ad='97c21958'
select count(*) from dba_jobs_running
END OF STMT
PARSE #1:c=0,e=548,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=107130104237
BINDS #1:
EXEC #1:c=0,e=1412,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=107130106034
WAIT #1: nam='SQL*Net message to client' ela= 12 p1=1650815232 p2=1 p3=0
*** 2006-11-21 21:40:53.931
FETCH #1:c=350760000,e=344612113,p=0,cr=2,cu=16652,mis=0,r=1,dep=0,og=4,tim=107474718456
WAIT #1: nam='SQL*Net message from client' ela= 1936 p1=1650815232 p2=1 p3=0
FETCH #1:c=0,e=6,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=0,tim=107474721309
WAIT #1: nam='SQL*Net message to client' ela= 8 p1=1650815232 p2=1 p3=0
*** 2006-11-21 21:56:30.972
WAIT #1: nam='SQL*Net message from client' ela= 915075702 p1=1650815232 p2=1 p3=0
XCTEND rlbk=0, rd_only=1
STAT #1 id=1 cnt=1 pid=0 pos=1 obj=0 op='SORT AGGREGATE (cr=2 r=0 w=0 time=100535896 us)'
STAT #1 id=2 cnt=0 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=2 r=0 w=0 time=100535876 us)'
STAT #1 id=3 cnt=5550 pid=2 pos=1 obj=0 op='MERGE JOIN CARTESIAN (cr=2 r=0 w=0 time=128639 us)'
STAT #1 id=4 cnt=10 pid=3 pos=1 obj=0 op='NESTED LOOPS OUTER (cr=2 r=0 w=0 time=5839 us)'
STAT #1 id=5 cnt=10 pid=4 pos=1 obj=69 op='FIXED TABLE FULL X$KSQRS (cr=0 r=0 w=0 time=4790 us)'
STAT #1 id=6 cnt=10 pid=4 pos=2 obj=202 op='INDEX UNIQUE SCAN OBJ#(202) (cr=2 r=0 w=0 time=561 us)'
STAT #1 id=7 cnt=5550 pid=3 pos=2 obj=0 op='BUFFER SORT (cr=0 r=0 w=0 time=90039 us)'
STAT #1 id=8 cnt=555 pid=7 pos=1 obj=16 op='FIXED TABLE FULL X$KSUSE (cr=0 r=0 w=0 time=1277 us)'
STAT #1 id=9 cnt=0 pid=2 pos=2 obj=0 op='VIEW (cr=0 r=0 w=0 time=344148954 us)'
STAT #1 id=10 cnt=105477 pid=9 pos=1 obj=0 op='UNION-ALL (cr=0 r=0 w=0 time=343814331 us)'
STAT #1 id=11 cnt=105476 pid=10 pos=1 obj=0 op='VIEW (cr=0 r=0 w=0 time=203487737 us)'
STAT #1 id=12 cnt=105476 pid=11 pos=1 obj=0 op='UNION-ALL (cr=0 r=0 w=0 time=202961626 us)'
STAT #1 id=13 cnt=0 pid=12 pos=1 obj=272 op='FIXED TABLE FULL X$KDNSSF (cr=0 r=0 w=0 time=13633786 us)'
STAT #1 id=14 cnt=105476 pid=12 pos=2 obj=72 op='FIXED TABLE FULL X$KSQEQ (cr=0 r=0 w=0 time=188317145 us)'
STAT #1 id=15 cnt=0 pid=10 pos=2 obj=253 op='FIXED TABLE FULL X$KTADM (cr=0 r=0 w=0 time=76301426 us)'
STAT #1 id=16 cnt=1 pid=10 pos=3 obj=254 op='FIXED TABLE FULL X$KTCXB (cr=0 r=0 w=0 time=62693462 us)'
STAT #1 id=16 cnt=1 pid=10 pos=3 obj=254 op='FIXED TABLE FULL X$KTCXB (cr=0 r=0 w=0 time=62693462 us)'
<---- END of TRACE FILE --> -
'select count(*) from x' returns 5460 rows and 'Select * from x' returns 0 rows
As you can see in the next lines something is wrong in my Oracle (8.0.6 on Win NT 4.0 sp 6a) :
Oracle8 Enterprise Edition Release 8.0.6.0.0 - Production
With the Partitioning option
PL/SQL Release 8.0.6.0.0 - Production
SQLWKS> SELECT * FROM V_TERRA_TE;
PERIOD_DATE PERIOD_TIME TERRARCV TERRASND TERCV TESND
0 rows selected.
SQLWKS> SELECT COUNT(*) FROM V_TERRA_TE;
COUNT(*)
5460
1 row selected.
V_TERRA_TE is a complex join of 5 Tables :
CREATE OR REPLACE VIEW "ACTUATE".V_TERRA_TE AS Select to_date(to_char(p1.period_date,'YYYYMMDD'),'YYYYMMDD') "PERIOD_DATE",
to_date(to_char(p1.period_time,'HH24:MI'),'HH24:MI') "PERIOD_TIME",
to_number(p1.caudalrcv + ((p3.caudalrcv + p4.caudalrcv)*(confterrate.conexadslterra/confterrate.conexadsltotal))) "TERRARCV",
to_number(p1.caudalsnd + ((p3.caudalsnd + p4.caudalsnd)*(confterrate.conexadslterra/confterrate.conexadsltotal))) "TERRASND",
to_number((p2.caudalrcv * confterrate.pctinfonegocio) + ((p3.caudalrcv + p4.caudalrcv)*(confterrate.conexadslte/confterrate.conexadsltotal)))"TERCV",
to_number((p2.caudalsnd * confterrate.pctinfonegocio) + ((p3.caudalsnd + p4.caudalsnd)*(confterrate.conexadslte/confterrate.conexadsltotal)))"TESND"
from p1,p2,p3,p4,confterrate
where (p1.period_date=p2.period_date)and
(p1.period_date=p3.period_date)and
(p1.period_date=p4.period_date)and
(p1.period_time=p3.period_time)and
(p1.period_time=p4.period_time)and
(p1.period_time=p2.period_time)and
to_char(p1.period_date,'MMYYYY')=to_char(confterrate.period_datetime,'MMYYYY');
I think that some not reported error happens in the select * with some temporary space or similar but only the message '0 rows selected' is displayed (instead the real error)
Could somebody help me ?
Thanks in advance
FranciscoForcing the Join/sort to be made on Disk (not on memory) the problem not happens. This demostrate that ORACLE has a VERY IMPORTANT BUG : It returns 0 rows wich is false.
To force it to work on disk i use this parameters :
alter session set sort_area_size=0
alter session set hash_join_enabled=false
Note : probably is not the best combination or use of parameters, but using it the query works as espected. -
Wrong results from "Select count(*) from tbl"
I am the user of an Oracle DB and I am getting what
look like wrong counts using "Select count(*)" statments.
It first occurred when I tried to get monthly record counts with
Select count(*), month
from tbl
group by month
(Note this is the query I used with the exception
of a change in the table name. The month field is numeric)
All the monthly counts but one looked like it was 2x what it should be.
Oddly enough if I tried
Select count(*), month
from tbl
where month = 200302
group by month
OR
Select count(*), month
from tbl
where month in (200301 200302)
group by month
I got what looked correct.
I even got the 2X problem when I asked for a count on
the entire table using
Select count(*)
from tbl
One of our DBAs suggested the problem has somehting to do with
the indexes and not running analyze on the table recently.
I'll note also that the table is partitioned.
I think it's Oracle version 8.1.7.4.0 running on a Sun box.
Has anyone seen this before or does anyone have any
suggestions on the cause of the problem?
I have been told it has to do with indexes
and I know there are many indexes on this table.
The table is also partitioned.
Thanks,
- johnplz copy and paste here your tests
i am running 8.1.7.4.0 too and all is fine here...
(i heard about a count(*) problem but on a lite version of an old 8.0.x...)
Fred -
Select Count(*) from Sample_table - how to get the count using JDBC?
Hi All,
It would be glad if anyone could help me with this. The problem is that I have to get the 'count' of records selected from a arbitrary table say, 'sample_table'. Is that possible to form the SQL in JDBC as
Select Count(*) from Sample_table
and get the value of the count? If yes, how?
Thanks in advance
Prabzstmt = con.createStatement();
ResultSet recordcnt_rs = stmt.executeQuery("Select Count (*) as record_ctr From Sample_table");
recordcnt_rs.next();
record_ctr = recordcnt_rs.getInt("record_ctr");
hope this helps. -
DB2 8.1 to Oracle 11g with SQL Developer 3.0
Hi,
I started migrating my DB2 8.1 to Oracle 11g, with SQL Developer 3.0
Basically, I need to migrate TABLES.
I followed these steps:
1) I created a new Oracle database, tablespaces, users, etc.
2) Then, I created both (DB2 and Oracle) connections into SQL Developer 3.0. All works fine.
3) I start capturing one table with the "Copy to Oracle" feature. Done with no errors.
But when I compare the table structure, I see the following problems in Oracle:
a) All fields are NULLABLE = YES. SQL Developer show this field property correctly in DB2: NULLABLE = NO, but not migrated the same!
SOLUTION: All I want is that SQL Developer simply migrating the same value who I have in the DB2. But how?
b) In DB2 I have one field property called COLUM DEFAULT. In Oracle this property is called DATA_DEFAULT. The SQL Developer show this field property correctly for the DB2 tables (for example: 0.0, ' ', etc), but don't migrated the same value! All fields are configured to DATA_DEFAULT = NULL.
SOLUTION: I think this occurs because NULLABLE is migrated with the value YES. Well, all I need is the same above...
NOTE: I tested the SWISSQL DATA MIGRATION software, and it works fine. All tables, field properties and data are migrated sucessfull. But this program is trial version!
Well, I think all of this are BUGS into SQL Developer.
Please, anyone to help me?
Regards,
YlramWelcome to the forum!
>
I just did right click in the procedure body and found [Debug, Compile for Debug, Compile, Run].
>
You listed a bunch of things but you didn't say what steps you actually performed and what the result was.
Did you 'Compile'the procedure? until you compile the procedure you can't debug it.
I just created a new procedure and when I select the body it displays in the 'Code' window on the right. But the 'Debug' icon is not enabled because the procedure was not compiled for debug.
When I compile it for debug the 'Debug' icon is now enabled. -
How to find out when data was deleted from table in oracle and Who deleted that
HI Experts,
Help me for below query:
how to find out when data was deleted from table in oracle and Who deleted that ?
I did that to fidn out some data from dba_tab_modifications, but I m not sure that what timestamp shows, wether it shows for update,insert or delete time ?
SQL> select TABLE_OWNER,TABLE_NAME,INSERTS,UPDATES,DELETES,TIMESTAMP,DROP_SEGMENTS,TRUNCATED from dba_tab_modifications where TABLE_NAME='F9001';
TABLE_OWNER TABLE_NAME INSERTS UPDATES DELETES TIMESTAMP DROP_SEGMENTS TRU
PRODCTL F9001 1683 46 2171 11-12-13 18:23:39 0 NO
Audit is enable in my enviroment?
customer is facing the issue and data missing in the table and I told him that yes there is a delete at 11-12-13 18:23:39 in table after seeing the DELETS column and timestamp in dba_tab_modifications, but not sure I am right or not
SQL> show parameter audit
NAME TYPE VALUE
audit_file_dest string /oracle/admin/pbowe/adump
audit_sys_operations boolean TRUE
audit_syslog_level string
audit_trail string DB, EXTENDED
please help
Thanks
SamLOGMiner --> Using LogMiner to Analyze Redo Log Files
AUDIT --> Configuring and Administering Auditing -
Select data from table not in another table
Hi,
I want to select data from table A which is not in table B.
Currently I am doing:
select
snoA,
nameA,
dobA
from A
where snoA not in
(select snoB from A, B
where snoA = snoB
and nameA = nameB)
But above is very slow.
Can I do something like:
select
snoA,
nameA,
dobA
from A, B
where
EXCLUDE ( snoA = snoB and nameA = nameB)
Please note that I need the where condition on both the columns.
any help will be appreciated.
-- HarveyWhat are the approximate data volumes in A and B?
What is "very slow"?
What version of Oracle?
What is the query plan?
Without knowing anything about your system, my first thought would be to see if a NOT EXISTS happened to be faster for your data
SELECT snoA,
nameA,
dobA
FROM a
WHERE NOT EXISTS (
SELECT 1
FROM b
WHERE a.snoA = b.snoB
AND a.nameA = b.nameB )Of course, I'm not sure why you are joining A & B in your NOT IN subquery. It would seem like you would just need a correlated subquery, i.e.
SELECT snoA,
nameA,
dobA
FROM a
WHERE snoA NOT IN (
SELECT snoB
FROM b
WHERE a.snoA = b.snoB
AND a.nameA = b.nameB )That should be more efficient than the original query. The NOT EXISTS version may or may not be more efficient than the NOT IN depending on data volumes.
Justin -
Select Count(*) from... returns zero, select * from... returns 4000 recs?
Hi,
I have an odd situation where "select count(*) from my_view where some_clause" returns 0, but the exact same query fetching the data (ie "select * from my_view where some_clause") works fine and fetches, correctly, 4000+ records.
I have tried dropping and recreating the view, and collecting DB stats again, but the problem persists.
I had a look at the explain plans and they are very different, but both the SQL statements work fine on a copy of the database taken with impdp.
Does anyone have any suggestions on what might be going on here ?
Any help would be appreciated, I've run out of ideas !
Dave
Edited by: user10281551 on 18-Sep-2008 00:43
Edited by: user10281551 on 18-Sep-2008 00:44Maybe it's the bug that a function based index is present and gets incorrectly used in the select count(*) statement?
If that's not the case, then please show us more details, like the statement and both execution plans.
Regards,
Rob. -
Performance problems on a Oracle 11G with Windows 2008 64bits.
Hi everyone,
I have noticed that our db is going low and low every week. My server has 16GB RAM and 10GB are dedicated to the Oracle database, this is a 11.2.0.1 with Windows 2008 R2 SP1 64bits. I like to know acording to the nexts values what you guys recommend to adjust in the init.ora:
orcl.__db_cache_size=5402263552
orcl.__java_pool_size=33554432
orcl.__large_pool_size=33554432
orcl.__pga_aggregate_target=3657433088
orcl.__sga_target=6878658560
orcl.__shared_io_pool_size=0
orcl.__shared_pool_size=1308622848
orcl.__streams_pool_size=33554432
*.memory_target=10511974400
*.open_cursors=5000
*.optimizer_mode='RULE'
*.processes=300
Acording to the memory target on how values can be increased the processes, pga_agregate_target, etc.
Also we have problems related to the bug Bug 9593134 that “Connections to Oracle 11g are slow and can take anywhere from 10 seconds to 2 minutes.” there is a fix on linux by removing the dns names on it but anyone have experience on windows platforms?
Thanks for all and sorry for my english.
Regards.
Arturo.Regarding the long connection times, have you tried using network packet capture software (such as Wireshark) to determine what the client computer is doing when a connection attempt is initiated?
The Oracle Database time model statistics, along with the system wide wait events may help you diagnose the non-connection related performance issues (you should not just look at the statistics, but instead capture the current values, wait a period of time, capture the statistics again, and compare the changes in the statistic values). A statspack report might also help you - but a 10046 trace at level 8 or 12 is more appropriate if you are able to identify a couple of sessions that experience performance problems.
I do not suggest just blindly modifying parameters, although I am curious to know:
* Why the session level parameter OPEN_CURSORS is set to 5000 - do you expect a single session to hold open 5,000 cursors?
* Why are you using the deprecated RULE based optimizer?
* Why is the MEMORY_TARGET parameter used when the SGA_TARGET and PGA_AGGREGATE target are specified?
Charles Hooper
http://hoopercharles.wordpress.com/
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc. -
How to save the selected records from Table control in dialog programming
Hiiiiiiii Every1
Actually the problem is like this:-
I have to select some records from table control and then want to save the selected records in DB table.
Example
I have some rows having inforamtion bout employees...
Now what i want is that when i click on 'SAVE' button then these selected rows should be moved into DB table.
Sachin Dhingrasee below example, I have added INSERT option after DELETE option.
REPORT demo_dynpro_tabcont_loop_at.
CONTROLS flights TYPE TABLEVIEW USING SCREEN 100.
DATA cols LIKE LINE OF flights-cols.
DATA: ok_code TYPE sy-ucomm,
save_ok TYPE sy-ucomm.
DATA: itab TYPE TABLE OF demo_conn.
TABLES demo_conn.
SELECT * FROM spfli INTO TABLE itab.
LOOP AT flights-cols INTO cols WHERE index GT 2.
cols-screen-input = '0'.
MODIFY flights-cols FROM cols INDEX sy-tabix.
ENDLOOP.
CALL SCREEN 100.
MODULE status_0100 OUTPUT.
SET PF-STATUS 'SCREEN_100'.
ENDMODULE.
MODULE cancel INPUT.
LEAVE PROGRAM.
ENDMODULE.
MODULE read_table_control INPUT.
MODIFY itab FROM demo_conn INDEX flights-current_line.
ENDMODULE.
MODULE user_command_0100 INPUT.
save_ok = ok_code.
CLEAR ok_code.
CASE save_ok.
WHEN 'TOGGLE'.
LOOP AT flights-cols INTO cols WHERE index GT 2.
IF cols-screen-input = '0'.
cols-screen-input = '1'.
ELSEIF cols-screen-input = '1'.
cols-screen-input = '0'.
ENDIF.
MODIFY flights-cols FROM cols INDEX sy-tabix.
ENDLOOP.
WHEN 'SORT_UP'.
READ TABLE flights-cols INTO cols WITH KEY selected = 'X'.
IF sy-subrc = 0.
SORT itab STABLE BY (cols-screen-name+10) ASCENDING.
cols-selected = ' '.
MODIFY flights-cols FROM cols INDEX sy-tabix.
ENDIF.
WHEN 'SORT_DOWN'.
READ TABLE flights-cols INTO cols WITH KEY selected = 'X'.
IF sy-subrc = 0.
SORT itab STABLE BY (cols-screen-name+10) DESCENDING.
cols-selected = ' '.
MODIFY flights-cols FROM cols INDEX sy-tabix.
ENDIF.
WHEN 'DELETE'.
READ TABLE flights-cols INTO cols WITH KEY screen-input = '1'.
IF sy-subrc = 0.
LOOP AT itab INTO demo_conn WHERE mark = 'X'.
DELETE itab.
ENDLOOP.
ENDIF.
WHEN 'INSERT'.
READ TABLE flights-cols INTO cols WITH KEY screen-input = '1'.
IF sy-subrc = 0.
LOOP AT itab INTO demo_conn WHERE mark = 'X'.
itab1 = itab.
modify itab1.
ENDLOOP.
ENDIF.
if not itab1 is initial.
INSERT dbtab FROM TABLE itab1.
endif.
ENDCASE.
ENDMODULE. -
ORA-01446: cannot select ROWID from, or sample, a view with DISTINCT, GROUP
In my data model (load from a database) there is this data control and its accessor return.
When I drag the accessor return inside a jsf page I create a adf read only table (that has about 5000 rows), the I run the page and it works.
Since I want to display only 20 ( or 50 or 100 is the same) rows for each page I had changed the access mode from the default value "Scrollable" to "Range Paging" and then I ve selected range size 50.
Now if I run hte jsf page there are no data to display and if I press the small triangles to order the column or insert a word in the filter field I have the message ORA-01446: cannot select ROWID from, or sample, a view with DISTINCT, GROUP.
I dont know how to do to solve this problem.
StefanoAn other thing.
I solved this problem, maybe I dont understand the meaning of access mode and range size , since every value I choose of these 2 fields the visualization of the table doesnt change.
Maybe you are looking for
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Showing output to a command window
Hi Friends i have an application where i have implemented sockects (server-client) using client = new Socket(IP,port num); // client server = new ServerSocket(port num); // server clientSock = server.accept(); // server now im sending a SQL query fro
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Safari 6.0.5 crashing on certain sites
Safari is continually crashing on certain sites. Such as ESPN and a site with a java based game called warlight.net. I have done everything I can think of. Im a new MBP owner. So im in a bit of uncharted territory here. I could use some major help he
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I have a new windows laptop. How do I transfer my itunes from my previous laptop to this new one?
My old laptop is a dell and so is my new one. I want to transfer my itunes library from the old laptop to the new one. How?
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Tags created in Organizer missing from Window folder details
I am using Photoshop 5 and regularly tagging all input. When I use windows to see the list of what files are in a folder only a few of the tags are listed? I do not understand.
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Photo consuming hard drive storage but cannot be found.
My wife's 4s claims to have 5.0 GB of storage consumed by photos although the photos cannot be accessed from the phone or from a PC. This happened after having a broken screen replaced although I do not see how the two are related. The company that