Re: PCTFREE and ITL space on high insert table

> Stefan, the inserts are not parallel. They come from different sessions, one at a time.

I did not mean parallel DML, i meant INSERTs from different sessions (= doing stuff parallel). However your scope is only at second granularity for these 400 INSERTs in peak and so there is a high chance that you will not have 400 session active at the same time inserting data into the same block. In consequence you gonna need much less ITL slots and in addition ASSM I/O spreading on table block level kicks in as well.

Best Regards
Stefan Koehler

Freelance Oracle performance consultant and researcher Homepage: http://www.soocs.de
Twitter: _at_OracleSK

> Michael Cunningham <napacunningham_at_gmail.com> hat am 4. Mai 2016 um 16:59 geschrieben:
>
> These answers are incredible. I learned a lot and got some great ideas.
>
> Stefan, the inserts are not parallel. They come from different sessions, one at a time.
>
> Jonathan, the primary key is fom a sequence and, to date, I have not witnessed any problems with waits. However, if you have something in
> particular I should be cautious of please let me know and I'll look into it.
>
> I'll move the partitions with pctfree 0 initrans 2, and look into using basic compression, but I'll leave the last partition at pctfree 10. I'll
> also look at sorting the data in each partition. In fact, I'll use Stefan's idea of dumping some of the latest blocks to see the ITL list count. It
> seems that pctfree 10 leaves room for 34 ITL's (24 bytes each). The inserts are not parallel so I'll assume they stay at 24 bytes. I have a couple
> days before all the partitions are moved until I get to the latest partition where I'll be using dbms_redefinition.
>
> Thanks for all the info, if there is any more, I'll take it.
> Michael

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