Re: Partition strangeness

  • From: "jaromir nemec" <jaromir@xxxxxxxxxxxx>
  • To: <Michael.Kline@xxxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Sat, 29 Jan 2005 13:01:14 +0100


> We've got a BUNCH of partitioned tables, but normally we add one month
> at a time, load it and analyze. Never had any problems.

If you use ANALYZE TABLE .. PARTITION (..)  the table statistics are not
populated. You may quick review it looking at all_tables view for the
partitioned table.

> When we tried 200412, the last of the old partitions, it was over 12

I expect you use insert select for populating the new partition and you
reference the partitioned table in the select. If so, do you reference all
partitions or only some of them? In the former case (i.e. there is nor
restriction on the partitioning key in the select) the (missing) table
statistics are used and should be gathered. You may experiment if some lower
estimating factor is sufficient.

Another possibility are the *derived* statistics (global_stats='N') using
dbms_stats. But I have no experience with this feature in Oracle 8. And
above all you must verify if the aggregation algorithm fits your data.


Jaromir D.B. Nemec

----- Original Message ----- 
From: "Kline.Michael" <Michael.Kline@xxxxxxxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Friday, January 28, 2005 12:05 AM
Subject: Partition strangeness


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