Has anybody worked with MT_OPTIMIZER_MODE and ST_OPTIMIZER_MODE to disable BaaN hints?

Let me put my question straight. What are the various options to disable baan hints? Seems there is some option in Oracle 9i to override BaaN hints?

ba6.1 -- -set MT_OPTIMIZER_HINT=""

That will send a blank hint. Or put that in your command line in your bwc file.

Tests have been executed with Oracle 9 and disabeling the driver hints. It resulted in very, very poor performance. The hint is stil useful because the Baan applicaion is mostly based on small result sets, while the Oracle optimizer mostly works for large result sets. So the less than 1% of the queries that are realy bad by the Oracle driver can mostly be improved by changing the code.

Hope this helps,
Dick

I did think there would be a performance impact by disabling BaaN hints. I wanted to know whats the feature in Oracle which overrides the hints passed from application.

OPTIMIZER_MODE=RULE and drop statistics :)

although, I heard that with 9i it will just regenerate the statistics anyway..
maybe not with RULE though..

Dave

Refer to -

'No hints' hint (http://www.baanboard.com/programmers_manual_baanerp_help_functions_query_hints_no_hints_hint)

'No hints' hint
--------------------------------------------------------------------------------
By default the driver generate a hint for each query it sends to the RDBMS (assuming the RDBMS supports hints of course). With the hint 'no hints' you tell the driver not to generate these default hints. The 'no hint' hint can be specified in combination with other hints. This may seem contradictory, however there are cases in which this can be useful. For information on this see the section Hint evaluation below.

The hint 'no hints' is only applicable to the Oracle level-2 driver. For any other driver this hint is ignored.

The "no hints" hint can only be used from from 3/4GL. So it should be set per query. There is no possibility to set it session or systemwide.

Kind regards,
Dick

Hi,

i am on baan4c4 and i am not able to use "hint" command in my select queries.

Is this feature only available for versions > 4 ?

JOchen

Hi,

i am on baan4c4 and i am not able to use "hint" command in my select queries.

Is this feature only available for versions > 4 ?

JOchen

That is correct,

Dick

hi dick & rest of ora gurus,

are there any good alternatives to make oracle use certain indexes, or optimizers in baan4c4 on ora 9i ?

E.g. is it sure when i make an "order by ....index2" in a select, that oracle 9i (level2) will take index 2 ?

we just migrated from triton to ora9i and experienced several performance issues. i read most of the threads here (thanks for all the tips!) and thus managed to optimize many sessions and ora params, but still there are some open questions ?

is there any good docu on how the level2 driver optimizes baan code, and how to write good/fast code ?

Thanks for your help
Jochen

In Baan 4 if you do an "order by <index>" Baan will send that index
as the hint.. in Baan 5 you can just say "hint ... "

Dave