RE: Performance Question - High I/O per Insert

Any triggers on the table that refer to data found in the current week's partition? This is a classic cause of high I/O per insert. Graeme

oracle-l-bounce_at_freelists.org wrote on 29/09/2004 05:27:28 AM:

> This is a follow-up to a question I posed earlier, but I have more info.
> A SQL*Loader conventional path load inserts rows into a table
> partitioned by week. On the first day of a new week, the load runs as
> efficiently as expected, but as the week goes on, the load goes more and
> more slowly. There is a single local index on each partition and the
> blevel is 2. I'm scratching my head. I realize I'm not providing much
> info, but can anyone tell me why loading into a partition might get
> slower as the partition fills? Thx!
>
>
> Mark Strickland
>
>
>
> ________________________________
>
> From: Mark Strickland
> Sent: Wednesday, September 22, 2004 12:42 PM
> To: oracle-l_at_freelists.org
> Subject: Performance Question - High I/O per Insert
>
>
>
> I'm trying to understand why I'm seeing a high number of I/Os for
> inserts. Inserts are through SQL*Loader conventional patch. Average
> row length is 129 bytes, no longs or blobs. The table has five indexes
> and each index has a blevel of 2. According to v$sqlarea, each insert
> uses 650 logical I/Os, 69 physical I/Os. I would expect fewer than 20
> I/Os per insert. There are db file sequential read waits on the data
> files that make up the index tablespace. That file system also contains
> the archived logs. Not surprised at the contention. Can someone point
> me in the right direction to understand this? Thx.
>
>
>
> Mark Strickland
>
> Drugstore.com
>
> Seattle, WA
>
>
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> http://www.freelists.org/webpage/oracle-l

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