Re: Oracle table inserts and creations

In article <Bt90L3.JGK_at_monitor.com> bag!howard (Howard Brenner) writes:
>If I know ahead of time that I will be inserting a large amount of data
>into a table is it more efficient to pre-allocate the space for the table
>or to let oracle do it when it needs to?

One possible gain in efficiency with pre-allocating or pre-extending the table before the data is inserted is a very small savings in overhead when the table grabs another extent during the insert if it was not pre-alloc'd/extended.

Make sure you precreate the table's storage parameters to have large enough extents to handle the large amount of data, ie you don't want to hit the *real* maxextents. You might notice a slight drop in performance (more overhead) if the table has very small extents and the insert will fill up each extent with data much faster, spending more time creating extents.

• Kathy Jou
• Oracle Corporation
• Disclaimer: I speak from my own experience and not for Oracle.