Slow inserts

From: <lowjw_at_my-deja.com>
Date: 2000/04/15
Message-ID: <8d8jio$s4u$1@nnrp1.deja.com>#1/1

Hi,

We have an application which we bulk inserts records into this large table.

It is doing something like 274 records / sec
(when the table is empty)

but when it reaches something like 10-12 million records, it simply slows down to abt 45 records / sec.

We fire 14 streams of this application
concurrently.

My first thoughts would be the indexes as from the session_Waits, it seem to indicate write waits completes on index datafiles and the figures can be seen to be increasing steadily
(from utlstat).

We dropped the indexes and re-run and it was still the same.
We start with an empty table and so I believe the search for free blocks may not be the cause.

The table is about 25 500Mb extents= 12.5 Gb. The index is about 2 500Mb extents=1 Gb.

I would also deduce that the filesystem could be the cause but our SA says the load on the machine is low and the iostats indicates this too.

So I'm quite puzzled as to why is this happening. I have already have 8 dbwr_io_slaves and 4 lgwr_io_slave up and running.

Joe

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Before you buy. Received on Sat Apr 15 2000 - 00:00:00 CDT