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stastics in datastage tables purpose
Posted: Mon Feb 28, 2011 9:04 am
by alexcol
Good morning.
In a producctin system, aour DBA is in charged to collect statistics to different tables in datasatge.
The question is ?
what are those statistics used for? for performance issues or another reason?
id appreciate your help
Posted: Mon Feb 28, 2011 9:27 am
by ppgoml
basically, statistics are used for database optimizer to build most proper access plan to achieve best performance
Posted: Mon Feb 28, 2011 10:33 am
by jwiles
As a table is updated over time (inserts/deletes/updates), the statistics on the table should be updated as well. If this is not done, the optimizer (as mentioned above) is accessing the table using outdated information and performance begins to decrease, sometimes dramatically depending on table size, activity and how long it's been since the last statistics "refresh". It is recommended to refresh statistics on a regular schedule to maintain performance goals.
Regards,
Posted: Mon Feb 28, 2011 10:42 am
by chulett
I don't believe that is the "statistics" being asked about here. With the "our DBA is in charged to collect statistics to different tables in datastage" comment, I was thinking this was more about audit/trending stats that need to be collected run over run.
Hopefully the OP can come back and clarify.