Gathering schema Statistics and Index rebuilding

I want to know after how much time we must gather the schema Statistics and Index rebuilding.
In our system approximately 7 logfile generates in one day
Please suggest me

Index rebuilding sounds so much Oracle 7! Indexes today generally take care of themselves quite well, throughout inserts, deletes and updates. It rebalances itself automatically when necessary, without requiring any rebuild. As for the stats, run it for sure after large data movements (i.e. deletes and inserts). Besides that, implement table monitoring for your tables, and run once in a while dbms_stats with the options parameter as GATHER STALE. That way, Oracle will automatically know which objects need their stats refreshed.
Daniel

Similar Messages

Different b/w index rebuild and index rebuild online

hi..guys could u plz tel me difference between index rebuild and index rebuild online

There is no difference in both the commands. Both will rebuild the index structure from the scratch.But in the first case with only Rebuild, as long as the index, its temporary segment is not prepared and merged together, index is not available for the other users for use. The Online clause makes the index available for others even while being rebuild.
Rebuilding index online has the same concept of creating them online to some extent,
http://download.oracle.com/docs/cd/B10501_01/server.920/a96521/indexes.htm#3062
HTH
Aman....

Statistics and indexes

hi gurus,
wat r bw statistics and indexes .... how to use them
thanx in advance

Anna,
Indexes are structures sorted by attribute values that contains a pointer to data stored in a table.
In plain words, when we run an indexing process on a table we basically build a pointer to that table records. That pointer has one main purpose: to enhance read performance (in our case - to enhance query performance).
BW Statistics are used in order to analyze the performance of queries and processes in the warehouse management (for example loading processes and aggregations). In order to use BW Statistics, you will need to enable them for your infoprovider and then be able to browse them from transcation ST03 or using the Technical Content Infoprovider and Queries.
See the Statistics How to: https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/5401ab90-0201-0010-b394-99ffdb15235b
Hope it helps,
Gili

Goldengate Extracts reads slow during Table Data Archiving and Index Rebuilding Operations.

We have configured OGG on a near-DR server. The extracts are configured to work in ALO Mode.
During the day, extracts work as expected and are in sync. But during any dialy maintenance task, the extracts starts lagging, and read the same archives very slow.
This usually happens during Table Data Archiving (DELETE from prod tables, INSERT into history tables) and during Index Rebuilding on those tables.
Points to be noted:
1) The Tables on which Archiving is done and whose Indexes are rebuilt are not captured by GoldenGate Extract.
2) The extracts are configured to capture DML opeartions. Only INSERT and UPDATE operations are captured, DELETES are ignored by the extracts. Also DDL extraction is not configured.
3) There is no connection to PROD or DR Database
4) System functions normally all the time, but just during table data archiving and index rebuild it starts lagging.
Q 1. As mentioned above, even though the tables are not a part of capture, the extracts lags ? What are the possible reasons for the lag ?
Q 2. I understand that Index Rebuild is a DDL operation, then too it induces a lag into the system. how ?
Q 3. We have been trying to find a way to overcome the lag, which ideally shouldn't have arised. Is there any extract parameter or some work around for this situation ?

Hi Nick.W,
The amount of redo logs generated is huge. Approximately 200-250 GB in 45-60 minutes.
I agree that the extract has to parse the extra object-id's. During the day, there is a redo switch every 2-3 minutes. The source is a 3-Node RAC. So approximately, 80-90 archives generated in an hour.
The reason to mention this was, that while reading these archives also, the extract would be parsing extra Object ID's, as we are capturing data only for 3 tables. The effect of parsing extract object id's should have been seen during the day also. The reason being archive size is same, amount of data is same, the number of records to be scanned is same.
The extract slows down and read at half the speed. If normally it would take 45-50 secs to read an archive log of normal day functioning, then it would take approx 90-100 secs to read the archives of the mentioned activities.
Regarding the 3rd point,
a. The extract is a classic extract, the archived logs are on local file system. No ASM, NO SAN/NAS.
b. We have added "TRANLOGOPTIONS BUFSIZE" parameter in our extract. We'll update as soon as we see any kind of improvements.

GATHERING schema statistics

Hi Guys...
I am running Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production on Solaris.
I have materialized views that I refresh and gather schema statistics everyday at midnight.
Normally the procedure takes few minutes to complete.
But now it's about three days the procedure running and is stuck on one table.
How do I tell as to whether the table is having issues with statistics gathering?
Or what would be the remedy for this situation?
Thanks in advance

Index rebuilding sounds so much Oracle 7! Indexes today generally take care of themselves quite well, throughout inserts, deletes and updates. It rebalances itself automatically when necessary, without requiring any rebuild. As for the stats, run it for sure after large data movements (i.e. deletes and inserts). Besides that, implement table monitoring for your tables, and run once in a while dbms_stats with the options parameter as GATHER STALE. That way, Oracle will automatically know which objects need their stats refreshed.
Daniel

[SOLVED] Gathering Schema Statistics from Form Builder

Hi
these are my database and Forms versions:
Forms [32 Bit] Version 6.0.8.8.0 (Production)
Oracle9i Enterprise Edition Release 9.0.1.1.1 - Production
PL/SQL Version 8.0.6.0.0 (Production)
I would like to build a form with a push button which when clicked will gather schema statistics using procedures from the DBMS_STATS package ie. using the command:
DBMS_STATS.gather_schema_stats (ownname => 'DLIC', cascade => true, estimate_percent => 99.99);
But when this line is added to the PLSQL code for the push button, i get the following error:
Error 0 at line 0, column 0
ORA-00600: internal error code, arguments:[17003], [59630960], [911], [1], [], [], [], []
Can any one please tell me what is the problem here?
Thank You.
Message was edited by:
One

Thanks Christian the W1zard and Francois D for your help! The solution IS, as you have suggested, to include the call to the DBMS_STATS procedure in a PLSQL block ie. using BEGIN ... END;
and the whole in a FORMS_DDL statement.
For any one facing the same problem, here is the entire solution:
--Code in push-button When-Button-Pressed trigger.
DECLARE
     STATEMENT_TO_EXECUTE VARCHAR2(200);
     OWN_NAME VARCHAR2(4);
     CASCADE_PARAM VARCHAR2(4);
     EST_PC VARCHAR2(5);
BEGIN
     OWN_NAME := 'DLIC';
     CASCADE_PARAM := 'TRUE';
     EST_PC := '10.99';
     STATEMENT_TO_EXECUTE := 'DBMS_STATS.gather_schema_stats(ownname=>'||''''||OWN_NAME||''''||',cascade =>'||CASCADE_PARAM||',estimate_percent=>'||EST_PC||')';
     FORMS_DDL('BEGIN '||STATEMENT_TO_EXECUTE||'; END;');
END;
Note that all parameters passed to the DBMS_STATS procedure is stored in a bind variable. Also, note that the parameter that is of type VARCHAR2, in this case DLIC or Ownname is preceded and succeded by '''' or 4 single-quotes.
PS:
Would be very helpful if someone explained why 4 single-quotes. I found this in another post in the OTN forum, but not quite sure of the theory behind it.
Thank You.

Steps after the Gathering schema statistics

i am getting schema statistics using these statements
begin
dbms_stats.gather_schema_stats(ownname => 'FSL',estimate_percent => dbms_stats.auto_sample_size, method_opt => 'for all columns size auto');
end;
Now after issuing these statement which steps required

Which version of oracle are you using? Because, if you are using oracel 9i then, estimate_percent => dbms_stats.auto_sample_size, will collect 100% statistics. Its a kind of bug in oracle 9i Rel.2.
Once you collect the statstics, nothing to be done from yourside, because, CBO will comes in picture during parsing your queries with best execution plan based on your objects statsitics.
Jaffar

Gathering Schema statistics automatically

Hi All,
I have a couple of doubts regarding automatic statistics gathering in Oracle 9i.
I have seen a metalink document telling that in 9i statistics can be gathered automatically by giving options => 'GATHER AUTO'. My doubt is
1) Once this statement is executed, dont we require running it any time afterwards? ie, will the statistics be gathered automatically for all objects in this schema without our intervention henceforth?
2) It is mentioned to execute the following statement before the one above "exec dbms_stats.ALTER_SCHEMA_TAB_MONITORING('<owner>',TRUE);"
If we enable table monitoring will it impact the database perfromance by any means? Will there be any overhead associated with table monitoring?
Please clear my above doubts regarding the DBMS_STATS. Also could you please inform me which is the better way to gather object statistics for a schema.
Thanks in advance
Satish

1) Yes, you need to create a job inside oracle (recommended) or a batch in your OS to calculate statistics in the interval (daily,weekly,etc) that you want. If you just execute it once only that time the statistics will be calculated.
2)Yes, "it's recommended" but not mandatory. Except:
http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_stats.htm#sthref6562
Well I think there will be some sort of impact, but I'm not sure how much. I once had that in a prod DB and I didn't noticed any kind of impact. You should test it before.
I don't think there's a rule to know which way is better to gather statistics, because some options for DBMS_STATS applies for some cases and others for a complete different case.
Depends in the type of DB that you have.

MV and index rebuild

Hi
Does rebuild (move to another tablespace) of indexes on a fact table in any way affect materialized views/logs created on that table? I know that it shouldn't but we have had some pretty strange things with our mviews, so i just have to ask :).
Thanks

It should not. What was the problem you had?

How to select all indexes in a schema , for gathering the statistics

In OEM 10g , How can we select all the indexes in a particular schema for gathering the statistics.
For example , consider the schema got 1500 indexes. When i clicked on select all , it is selecting 10 indexes in one stretch ( all which are present in that page).
For 1500 indexes , i have to make 150 such selection.
How can we avoid it.
In 9i OEM, its quite simple. With just 1 mouse clicke , we can select all the indexes .
Thanks
Naveen
314 439 9554

On the Administration Tab of the instance, choose Statistics Management - Manage Optimizer Statistics, then Gather Optimizer Statistics and click Continue. You then get a choice of Database, Schema, Tables or Indexes.
Stupid that you have to supply an OS username and password to do this but anyway.

EAR4 - Gathering Statistics, unusable indexes and more

Hi,
Some feedback on statistics:
1. When choosing a table -> Statistics -> gather Statistics, the minimum is to have a CASCADE option (so all the indexes will be analyzed too). I think it should be the deafult! This way there is a chance that the developers will have good statistics...
As a bonus, an advanced tab with the rest of the options might be nice, when you have time.
2. When choosing to gather statistics on an index, you should you dbms_stats and not ALTER INDEX... COMPUTE STATISTICS which is a deprecated syntax.
And about indexes:
1. When looking at the index tab of a table, unusable indexes should be visibly different - maybe just color the status column. Well, any color-coding can help to gain more infomation very fast (index types and index status). Well, I guess the same goes for disabled triggers, disabled constraints etc...
2. When right-clicking an index in an index tab of a table, the only option is export, which makes no sense. Could you replace it with the six relevant index options, just like when we right click an index in the side bar (drop, rebuild, rename, make unusable...)
Well, same goes for the triggers tab of a table - when right-clicking a trigger give us the trigger actions(enable/disable, drop...), not export.
my two cents,
Ofir

When Choose a partitioned table from the tables list (tree view on the left), I have many tabs with details (Columns, data, indexes,etc).
1. The last tab, SQL, doesn't generate any CREATE TABLE sql at all for the simple partition table I created (10g Release 2 on windows 2000, raptor 4.1, a table with a single partition).
2. There is no way to see the partitions definitions - for example, the list of partitions and their ranges (or list values). I would like to have another tab for partitioned table with that information (from all_tab_partitions). Also, how can I easily see the type of partitioning and the partition key of the table?
3. Also in the builtin reports, there is no way to get that data. The only report about partitioned tables that I see is Table -> Organization -> Partitioned -> Partitioned Tables, that only provide owner, table_name, maybe tablespace and logging (blank in my case).. I think:
a. You should rewrite the report to use dba/all_part_tables - with columns like partitioning_type, subpartitioning_type, partition_count etc.
b. add a report about the partition key columns per partitioned table from dba_part_key_columns.
4. When adding an index to a partitioned table, I can't choose local/global index. The index is always created as a global index. For example, can't create bitmap index on partitioned tables because they must be local.
Ofir

Update Statistics and Rebuild of Indexes

Hi friends,
If I execute the Update statistics for a given table thru DB20 does it have any effect on the indexes of this table or is it necessary to rebuild the index using db02
Regards
Aliila

Updating Statistics does not rebuild index while in update states logs it will show you information regarding which indexes needs to be rebuiled which you can rebuild by brtools or executing rsanaora prg in se38.
Shivam

How to Gather Statistics of Tables and Indexes

Hi all,
Plz help me in Gathering Statistics of Tables and Indexes.
Thanks

for tables
exec dbms_stats.gather_table_stats('SCOTT', 'EMPLOYEES');
for indexes
exec dbms_stats.gather_index_stats('SCOTT', 'EMPLOYEES_PK');
check this link for detail
http://nimishgarg.blogspot.com/2010/04/oracle-dbmsstats-gather-statistics-of.html

Alter index rebuild calculates statistics?

Hi
Does anyone know if ALTER INDEX REBUILD gathers statistics on the index automatically? Does it do it at a 100% by default?
Thanks for your help!!!

On 10g+ the alter index command defaults to compute statistics which to the best o my knowledge is a 100% sample. With lower versions you need to specify that you want statistics: alter index owner.index_name rebuild compute statistics;
HTH -- Mark D Powell --

Display statistics history of tables and indexes

hi,
in display statistics history of tables and indexes i can see only one year old table history, how we can check the table history for more than one year?
Thanks,
Nithin

Welcome to SDN,
Please search on help.sap.com or SDN before you post your query to avoid duplicate thread.
I think below link will clear your doubt. help.sap.com/saphelp_nw70ehp1/helpdata/en/a6/8c933bf687e85de10000000a11402f/frameset.htm

Gathering schema Statistics and Index rebuilding

Similar Messages

Maybe you are looking for