Autom. Gather Statistics Job
Hello,
i am facing following problem with the automatic gather statistics job which is running every night.
The jobs starts when the weeknight/weekend_maintenance_windows opens, runs approx. 30 minutes and rebuilds statistics for around 270 objects. But when we check the status of objects next morning or immediate after jobrun, we still find hundrets of objects with stale statistics. We are not facing any heavy performance problems, but i want to know why we found stale statistics. The job uses 30 minutes of the 480 minutes window, so in my opinion there is plenty of time for all objects to create new statistics.
Is this normal behaviour?
Can't find anything in metalink.
Systeminfo:
Host: HP-UX 11.31
DB: 10.2.0.4
Regards
Ulli
Ulli,
uwaldt wrote:
Hello Randolf,
we check if column stale_stats contains a 'YES'. The column 'last_analyzed' is filled with a date.OK, and the date corresponds to the latest run of the automatic statistics gathering job or is it outdated? What is the content of the corresponding TABMODIFICATIONS view in that case?
After we check sthe SQL-script with the 'original' check via dbms_stats.gather_schema_stats, we see that there is a difference between all_tab/ind_statistics and the real value in tabmodifications.Apologies, but I'm not able to follow: What is the "difference between all_tab/ind_statistics and the real value in *_tab_modifications"? You mean to say that the list of objects marked as "STALE_STATS = YES" column differs from the output of the "LIST STALE" call?
But what shows grid-control if we check there for stale stats?Good question, I can't answer since I seldom use the GUI tools.
The next is, the developers in house argue with the all_tab/ind_statistics and blame the DBA's to do their housekeeping, especially if the users complain bad performance. I knew that the gather_job do his work, but we can't show it probable to the developers.This all sounds a bit odd. Two comments:
1. It is possible in 10g to lock the statistics of tables, so that the automatic statistics collection job doesn't touch them. It's quite unlikely since you have to invoke it manually/explicitly using DBMS_STATS.LOCK_TABLE/SCHEMA_STATS, but may be you want to check the column STATTYPE_LOCKED in the TABSTATISTICS views for those objects in question, just to make sure.
2. All the monitoring related information (*TABMODIFICATIONS/STALE_STATS column etc.) is usually only updated every three hours or if a call to DBMS_STATS.GATHER_STATS is performed. If you want to manually invoke the flush of the monitoring info, you can call DBMSSTATS.FLUSH_DATABASE_MONITORING_INFO to make sure that you look at the latest monitoring information available.
Above point might explain that you can spot differences/inconsistencies before/after calling DBMS_STATS.GATHER_SCHEMA_STATS to list the stale objects.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/
Similar Messages
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Exclude Schema from Gather Statistics Job
I am using 11.1.0,7. I would like to know if we can exclude some schemas While Oracle automatically gathers the statistics.
Reason I want this is that, I have one database that supports multiple applications but as per one application's demand we should not be gathering stats on it's schema. So, in totality I have 20 Schemas but while this jobs run, I want to exclude 2 schemas that this application supports.
Locking the Stats for these schemas is not an option.
Thanks!Have you enquired from the vendor exactly why they do not want you to gather statistics on it's schema?
Is there other options they are willing to consider like baselining the explain plan or perhaps not publishing the statistics to the tables...using the pending statistics feature?
Exec dbms_stats.set_table_prefs('SH', 'CUSTOMERS', 'PUBLISH', 'false');
Regards
Tim Boles
Edited by: Tim Boles on Aug 4, 2010 11:11 AM -
Hi,
I am using 11.1.0.7 on IBMAIX Power based 64 bit system.
In 10g, if i query dba_scheduler_jobs view, i see the GATHER_STATS_JOB for automated statistics collection but in 11g i don't see this rather i see BSLN_MAINTAIN_STATS_JOB job which executes BSLN_MAINTAIN_STATS_PROG program for stats collection.
And if i query DBA_SCHEDULER_PROGRAMS, i also see GATHER_STATS_PROG program here. Can gurus help me understanding both in 11g. Why there are two different programs and what is the difference?
Actually the problem is that i am receiving following error message in my alert log file
Mon Aug 16 22:01:42 2010
GATHER_STATS_JOB encountered errors. Check the trace file.
Errors in file /oracle/diag/rdbms/usgdwdbp/usgdwdbp/trace/usgdwdbp_j000_1179854.trc:
ORA-00054: resource busy and acquire with NOWAIT specified or timeout expiredThe trace files shows
*** 2010-08-14 22:10:14.449
*** SESSION ID:(2028.20611) 2010-08-14 22:10:14.449
*** CLIENT ID:() 2010-08-14 22:10:14.449
*** SERVICE NAME:(SYS$USERS) 2010-08-14 22:10:14.449
*** MODULE NAME:(DBMS_SCHEDULER) 2010-08-14 22:10:14.449
*** ACTION NAME:(ORA$AT_OS_OPT_SY_3407) 2010-08-14 22:10:14.449
ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired
*** 2010-08-14 22:10:14.450
GATHER_STATS_JOB: GATHER_TABLE_STATS('"DWDB_ADMIN_SYN"','"TEMP_HIST_HEADER_LIVE"','""', ...)
ORA-00054: resource busy and acquire with NOWAIT specified or timeout expiredBut we dont have GATHER_STATS_JOB in 11g and also the job BSLN_MAINTAIN_STATS_PROG runs only on weekend and the above error message came last night 16 August.
Thanks
SalmanThanks for the people who are contributing.
I know from the information that table is locked, but i have tried manually locking a table and executing gather_table_stats procedure but it runs fine. Here i have two questions
Where is GATHER_STATS_JOB in 11g as you can see the text of trace file where it says that GATHER_STATS_JOB failed, i dont see there is any GATHER_STATS_JOB in 11g.
BSLN_MAINTAIN_STATS_JOB job is supposed gather statistics but only on weekend nights, then how come i see this error occurring last night at 22:11 on 16th August which is not a week end night.
Salman -
How I gather statistics via OEM db control?
Hi,
According to the documentation,
I may setup a job to automatically
gather statistics for all the segments in my database
via EM database control.
I cant find any documentation on how to do this.
I did find a link in EM which will allow me
to gather statistics ad hoc but I want it automated.
Thanks,
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by default. Check under Database > Administration >
Scheduler > Jobs in Database Control. The job is called
SYS.GATHER_STATS_JOB. You will need to login as SYS to
see the job. The job runs the
DBMS_STATS.GATHER_DATABASE_STATS_JOB_PROC procedure.
You can, of course, schedule any other
DBMS_STATS.GATHER_* procedures if you prefer.
Hope this helps.
Kailash. -
Hi,
I launched a job to gather statistics on just one schema on my DATABASE in OEM. How can I identify it's session ? Many thanks before.You can try below query:
select s.username, s.sid,s.serial#, sql.sql_Text
from v$session s, v$sqlarea sql
where s.sql_address = sql.address and s.sql_hash_value = sql.hash_value and
s.username = '&username' and lower(sql.sql_text) like '%dbms_stats%'
Best Regards
Krystian Zieja / mob -
Gather Statistics taking very long time
Hi,
In one of our critical Databases gather statistics is taking a very long time.
How do I go about debugging this bad performance?
Regards,
NarayanStart with
- What is the exact command used to gather statistics (and what are all the global settings that are used for any arguments you're not providing)?
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Gather Statistics recommendations
Hi
How to find the recommendations from gather schema statistics job?
Thanks998932 wrote:
Sometimes when a Gather Schema stats job is scheduled(parameters:APPLSYS, 30, , NOBACKUP, , LASTRUN, GATHER, , Y), it will get executed in 25 minutes and sometimes 60 minutes.
a) What could be the possible reasons?This is normal and it depends to how busy your system is.
b) How can I reduce the execution time?How big is your database and how long it takes to gather stats for all schemes?
What if you change 30 to 10, does it make a difference?
c) What If I increase the estimate percent and give the Degree values?
PROD CPU's are 12, cores are 6 and RAM is 72 GBYou need to try it yourself and see how long it takes. Increasing the estimate percent will take longer but with different degree value this might make it different. You should tweak your parameters to find the best values and your concern should be about your system performance after running gather schematic stats instead of how long the program takes to run.
Thanks,
Hussein -
How to Schedule Java statistics job
Hi All,
We have a installed a NW07 Portal system on one of the unix boxes.Now we would like to run the oracle statistics on the same. Since there is no ABAP stack, we can't schedule the same thru db13. Is there anyway we can run the same.
Can I configure the Java statistics jobs for this from the central solution manager using the DBACOCKPIT.
Can somebody tell how to do this??
Thanks for the help.
Regards
RaviRavi,
Chek out the Following SAP Note as well as the PDF's to accomplish the task.:
Note 1027146 - Database administration and monitoring in the DBA Cockpit
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/107aa3f5-2302-2a10-f990-b4d2af1aaca0
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/1062428c-f1df-2910-b08f-c322feddcd10
Regards,
Karthick Eswaran -
Hi folks!
I gathered statistcs in one schema with folowing options:
exec dbms_stats.gather_schema_stats(user,method_opt=>'FOR ALL COLUMNS SIZE 1',estimate_percent=>null,gather_temp=>false,cascade=>true,degree=>dbms_stats.auto_degree);Then:
exec dbms_stats.gather_schema_stats(user,method_opt=>'FOR ALL COLUMNS SIZE SKEWONLY',estimate_percent=>null,gather_temp=>false,cascade=>true,degree=>dbms_stats.auto_degree);Now, I turn on table monitoring and suggest to gather statistics (per day) with that parameters:
dbms_stats.gather_schema_stats(ownname =>user, options=>'GATHER STALE', gather_temp => false, cascade => true, estimate_percent => 100, degree => dbms_stats.auto_degree);Default method_opt is FOR ALL COLUMNS SIZE AUTO.
Now I got better perfomance. How often I need to gather statstics?
Thanks in advance.
Best regards, Pavel.Thanks, I also think so.
Little test-case:
SQL>exec dbms_stats.gather_table_stats(user,'TABLE1',estimate_percent=>null);
Elapsed: 00:00:01.03
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE1;
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
DISGRP 7944 33204
DISMBR 18948 33204
TYPE 4 33204
Elapsed: 00:00:00.03
SQL> exec dbms_stats.gather_table_stats(user,'TABLE1',estimate_percent=>10);
PL/SQL procedure successfully completed.
Elapsed: 00:00:01.78
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE1';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
DISGRP 3836 3269
DISMBR 13686 3269
TYPE 4 3269
Elapsed: 00:00:00.00
SQL> exec dbms_stats.gather_table_stats(user,'TABLE1',estimate_percent=>100);
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.52
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE1';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
DISGRP 7944 33204
DISMBR 18948 33204
TYPE 4 33204
Elapsed: 00:00:00.01
SQL> exec dbms_stats.gather_table_stats(user,'TABLE1',estimate_percent=>dbms_stats.auto_sample_size);
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.53
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE1';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
DISGRP 8448 5568
DISMBR 18948 33204
TYPE 4 5568
Elapsed: 00:00:00.00
SQL> select count(distinct disgrp) from TABLE1;
COUNT(DISTINCTDISGRP)
7944
Elapsed: 00:00:00.02
SQL> select count(distinct dismbr) from TABLE1;
COUNT(DISTINCTDISMBR)
18948
Elapsed: 00:00:00.03
SQL> select count(distinct type) from TABLE1;
COUNT(DISTINCTTYPE)
4
Elapsed: 00:00:00.01
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE2';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
ID 219120 219120
UNIT 114762 219120
LOC 61 219120
TIS 1230 219120
RTYP 3 219120
Elapsed: 00:00:00.02
SQL> exec dbms_stats.gather_table_stats(user,'TABLE2',estimate_percent=>null);
PL/SQL procedure successfully completed.
Elapsed: 00:00:07.61
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE2';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
ID 219120 219120
UNIT 114762 219120
LOC 61 219120
TIS 1230 219120
RTYP 3 219120
Elapsed: 00:00:00.00
SQL> exec dbms_stats.gather_table_stats(user,'TABLE2',estimate_percent=>10);
PL/SQL procedure successfully completed.
Elapsed: 00:00:02.90
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE2';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
ID 219950 21995
UNIT 70812 21995
LOC 43 21995
TIS 496 21995
RTYP 3 21995
Elapsed: 00:00:00.00
SQL> exec dbms_stats.gather_table_stats(user,'TABLE2',estimate_percent=>50);
PL/SQL procedure successfully completed.
Elapsed: 00:00:03.70
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE2';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
ID 218716 109358
UNIT 92338 109426
LOC 61 109455
TIS 994 109567
RTYP 3 109422
Elapsed: 00:00:00.00
SQL> exec dbms_stats.gather_table_stats(user,'COMPS',estimate_percent=>100);
PL/SQL procedure successfully completed.
Elapsed: 00:00:04.37
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE2';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
ID 219120 219120
UNIT 114762 219120
LOC 61 219120
TIS 1230 219120
RTYP 3 219120
Elapsed: 00:00:00.00
SQL> exec dbms_stats.gather_table_stats(user,'COMPS',estimate_percent=>dbms_stats.auto_sample_size);
PL/SQL procedure successfully completed.
Elapsed: 00:00:03.81
SQL> select column_name,num_distinct,sample_size from user_tab_col_statistics where table_name='TABLE2';
COLUMN_NAME NUM_DISTINCT SAMPLE_SIZE
ID 217968 54492
UNIT 122237 54492
LOC 31 5495
TIS 240 5495
RTYP 3 5495
Elapsed: 00:00:00.01
SQL> select count(distinct id) from TABLE2;
COUNT(DISTINCTID)
219120
Elapsed: 00:00:00.27
SQL> select count(distinct unit) from TABLE2;
COUNT(DISTINCTUNIT)
114762
Elapsed: 00:00:00.30
SQL> select count(distinct loc) from TABLE2;
COUNT(DISTINCTLOC)
61
Elapsed: 00:00:00.06
SQL> select count(distinct tis) from TABLE2;
COUNT(DISTINCTTIS)
1230
Elapsed: 00:00:00.09In that situation, auto_sample_size not bad? But estimate_percent=>100 - exact.
Best regards, Pavel. -
How to Gather Statistics of Tables and Indexes
Hi all,
Plz help me in Gathering Statistics of Tables and Indexes.
Thanksfor tables
exec dbms_stats.gather_table_stats('SCOTT', 'EMPLOYEES');
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check this link for detail
http://nimishgarg.blogspot.com/2010/04/oracle-dbmsstats-gather-statistics-of.html -
Dear All,
I keep getting the following error message when trying to run the update statistics job, I wanted to know what would be the best approch as it is a critical server please?
failed with the following error: "Could not allocate space for object 'dbo.'databasename'.'PK_'''''''' in database 'databasename' because the 'PRIMARY' filegroup is full. Create disk space by deleting unneeded files, dropping objects in the filegroup,
adding additional files to the filegroup, or setting autogrowth on for existing files in the filegroup.".
Thank you in advance!Thank you for your reply! there are already 2 primary files and I'm not sure if there are any implications on creating more files. One of the primary files are set to grow by 500mb with unrestricted grow and the other file with 500mb with restiricted
grow?
There is no need to create multiple data files if one of your data file is on RAID 10.You can create secondary data file if primary data file is on disk which is almost full .If both files are on same drive it is useless
What you should do is disable autogrowth on one data file which seems to be large and will run out of space in near future .enable autogrowth fro data file which is small and then try running updatestats you will suceed
Please mark this reply as the answer or vote as helpful, as appropriate, to make it useful for other readers -
Automated/batch printing job?
Hi all,
We are using BW 3.5 and I was wondering if there is a way to set up an automated batch print job. (ie. let's say that once a month a report is generated automatically, is there a way to tell BW to print that report automatically at a given time without user interaction?)
Thanks for any help you can offer and points will be awarded to helpful replies.How would I go about doing that?
From the research I've done, I believe background printing can be done using BEx Broadcaster in BI 7.0 but not BI 3.5. Is this accurate or is there another way to accomplish this in BI 3.5?
Thanks. -
exec dbms_stats.gather_schema_stats( -
ownname => 'PROD1, -
options => 'GATHER AUTO', -
estimate_percent => dbms_stats.auto_sample_size, -
method_opt => 'for all columns size repeat', -
degree => 25 -
I have 400 tables in PROD1 schema, but I want to gather statistics for 120 tables only
How to gathere statistics for 120 tables ?
For specifying degree, what is the minimum and maximum? Will this affect any performanceuser8934564 wrote:
exec dbms_stats.gather_schema_stats( -
ownname => 'PROD1, -
options => 'GATHER AUTO', -
estimate_percent => dbms_stats.auto_sample_size, -
method_opt => 'for all columns size repeat', -
degree => 25 -
I have 400 tables in PROD1 schema, but I want to gather statistics for 120 tables only
How to gathere statistics for 120 tables ?
For specifying degree, what is the minimum and maximum? Will this affect any performanceFrom Oracle Docs:
Degree is Degree of parallelism. The default for degree is NULL. The default value can be changed using the SET_PARAM Procedure. NULL means use the table default value specified by the DEGREE clause in the CREATE TABLE or ALTER TABLE statement. Use the constant DBMS_STATS.DEFAULT_DEGREE to specify the default value based on the initialization parameters. The AUTO_DEGREE value determines the degree of parallelism automatically. This is either 1 (serial execution) or DEFAULT_DEGREE (the system default value based on number of CPUs and initialization parameters) according to size of the object.To be able to gather stats for 120 tables:
1) You can create a temporary table, enter the names of these tables, create a PL/SQL procedure, loop for the table names and call GATHER_TABLE_STATS for each table.
2) You can lock other table's stats, and call GATHER_SCHEMA_STATS.
Regards
Gokhan -
About gather statistics - ANALYZE on Oracle views
Oracle® Database Reference
11g Release 1 (11.1)
Part Number B28320-01
ALL_TABLES describes the relational tables accessible to the current user. To gather statistics for this view, use the ANALYZE SQL statement.
Columns marked with an asterisk (*) are populated only if you collect statistics on the table with the ANALYZE statement or the DBMS_STATS package
I thought ANALYZE command shouldn't be used to gather stats, as it explained as well on the ANALYZE command description.
Furthermore, explanations on how the columns should be populated are not clear enough. Maybe my english level is too low, but it seems we have to run any thing on the view itself.
Same for ALL_INDEXES.
Nicolas.Hi Nicolas. You're right that we recommend using DBMS_STATS for most statistics-gathering purposes. I'll pass this along to the writer who manages the Database Reference, to see that it gets updated. I'll also ask him to check the clarity of the column descriptions.
Regards,
Diana -
Suggested schedule for gather statistics on sysadm
We have recently upgraded to 11.1.0.7 with psoft version 9.0 and tools 8.49 on sun solaris version 10. Currently we are running stats every night on all non work sysadm tables. I'm wondering if this is too much. We are seeing sql statements use different explain plans. For ex: one sql takes plan A and finishes in expected time. At some other point during the week that same sql will take plan B and will either never finish or take way too long.
So I'm curious to see how other folks are handling their statistics.
Other items of note:
we disabled the nightly oracle statistics job
our database is about 200 GB of used space
In any feedback is much appreciated.Welcome to the forum!
Whenever you post provide your 4 digit Oracle version (result of SELECT * FROM V$VERSION)
>
For example there is a table T1 with 25GB size (3 crores rows) and partitioned when i try generating statistics for a T1 table with below command it takes lots of time and i dont know what is the progress.
>
Your command will generate statistics for the entire table; that is, ALL partitions. Is that what you intended?
Sometimes partitioned tables have historical data in older partitions and a small number of ACTIVE partitions where the amount of data changes substantially. You could collect stats only on the partitions that have large data changes. The older, static partitions may not need frequent stat collections since the amount of data that changes is small.
If you are using 11g you could collect incremental statistics instead of global stats. Here is an article by Maria Colgan, an Oracle developer on the Optimizer team on stats.
https://blogs.oracle.com/optimizer/entry/how_do_i_compare_statistics
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