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Re: database table write on read

From: MotoX <rat_at_tat.a-tat.com>
Date: Thu, 23 Jul 1998 12:38:02 +0100
Message-ID: <901193798.5539.0.nnrp-06.c2de712e@fews.demon.co.uk>


Yep, it's 'block cleanout'.

I had the same problem after largm data loads into datawarehouse tables. Oracle Tech. Support suggest that once these big transactions have run you do a 'select count(*)' from each table.

MotoX.

Duane Tiemann wrote in message
<6p5hn9$gh8$1_at_newssvr04-int.news.prodigy.com>...
>We have observed some file write activty by Oracle which we don't
>understand. We've replicated the situation on a test system as follows:
>
>We insert a few rows which have a long raw column with 64000 bytes in it.
>After waiting several minutes (in which the rows seem to be successfully
>logged and written to the database) we retrieve any value from one of the
>rows.
>
>The retrieval results in write activity to the table. This is documented
by
>"select * from v$filestat" as well as AIX's iostat; The number of blocks
>written is the same as the number of database blocks included in all the
>rows inserted.
>
>Can anyone tell us why this write activity occurs?
>
>BTW, the 'extra' writing does not occur if we place 6K or less in the long
>raw column. It also does not occur on subsequent retievals -- only the
>first.
>
>More details:
>
> Oracle Version 7.3.3
> AIX Version 4.2.1
> Database block size 16384
>
>Thanks,
>
>Duane Tiemann
>Prodigy Services Co.
>duanetiemann_at_prodigy.net
>
>
>
Received on Thu Jul 23 1998 - 06:38:02 CDT

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