Re: dbms_stats / 9204

I haven't followed this through, but it looks as if it's related to the issue that Oracle apparently wants a minimum sample of 919 leaf blocks when sampling an index. So the theory is that if you do something like:

    estimate_percent=>10,
Oracle can work out if this meets the 919 block limit, and change the sample size if necessary. But it's only supposed to change the sample size upwards. When (as your bug note shows) you set 100% as the sample size, Oracle still adjusted it down to about 54% then got a small sampling error that resulted in a num_rows that was a little off.

In reply to your earlier question about sample_size - for indexes, this is the number of index entries that existed in the leaf blocks that were sampled.

-- 
Regards

Jonathan Lewis

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"Oradba Linux" <techiey2k3_at_comcast.net> wrote in message 
news:0S3yd.237219$V41.231021_at_attbi_s52...


> Are you using dbms_stats on 9204? Did you come across a bug  3301328 ?

> Index stats being collected is not accurate when compared to analyze

> commands.

> How about analyze commands using partition tables ? Any issues ......

>

>