_table_lookup_prefetch_size

[Former Member]

Has anyone implemented this on a VLDB (6tb+) that can comment on the performance degradation, if any?

[Former Member]

Hi,

this is an internal parameter and with out the Oracle's recommendation this should not be set. What is your need? can you please let us know your idea/purpose setting this parameter?

There is a bug identified by setting this parameter.

If you have a Oracle metalink, check out Metalink# 406966.1

[Link|http://www.dba-oracle.com/oracle_news/news_returns_wrong_sql_result.htm].

Regards,

Srihari

Edited by: Srihari Rao on Aug 13, 2008 9:55 AM

[fidel_vales]

Hi Srihari,

That is a parameter recommended by SAP.

Check SAP notes:

830576 Parameter recommendations for Oracle 10g

124361 Oracle parameterization (R/3 >= 4.x, Oracle 8.x/9.x)

632556 Oracle 9.2.0.* database parameterization for BW

1109753 Table prefetching produces incorrect result sets

I think that answer your question.

@John

I'm sorry I cannot comment anything about VLDB.

Lets see if other readers have any comment about the original question.

[Former Member]

Hi Fidel,

Thanks for the information. Yep, the idea behind setting the prefetching is clear now.

Regards,

Srihari