RE: Export of very big table. Solution?

I tested this, but it made exactly NO difference. I think the select from the database is the slowest in the chain. I split the select into 7 pieces now, and it now writes at a 3.000.000 rows per hour rate. We estimate a grow of 50.000.000 records within 3 months -a week that is- so 50.000.000 / 3.000.000 = 17 hours. I think we will have to partition the table, not only by day (7.000.000 records) but by hour (300.000 records) This will create a monster unload of 168 simultaneous selects.....

Eric Lansu

> -----Original Message-----
> From: Mohan, Ross [SMTP:MohanR_at_STARS-SMI.com]
> Sent: Tuesday, January 09, 2001 4:12 PM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Export of very big table. Solution?
>
> what did you set the BS parameter to on the dd command?
>
> I have found increasing benefits up to about 128K, then
> it hits a knee and improvement is essentially flat.
>
> The default ( probably 2/4 K ) is too small.
>
> hth
>
> -----Original Message-----
> From: eric.lansu_at_dutchtone.nl [ <mailto:eric.lansu_at_dutchtone.nl>]
> Sent: Tuesday, January 09, 2001 7:21 AM
> To: Multiple recipients of list ORACLE-L
> Subject: Export of very big table. Solution?
>
>
> Hello Listers,
>
> Some time ago I asked you how to export a very big file. The solution was
> in
> piping and UNIX-split.
> We did this before, but what we didn't do was dd-ing from the pipe to the
> dump file. We piped it straight in. It looks like this solved our
> corruption
> problem on compressed exports files.
>
> The problem remains it's very slow. Our exports may be in order now, but
> there's no way we can use them anymore. Next thing we are investigating is
>
> 'select'-ing it to a comma-delimited file, and restore it with SQL*Loader.
> A
> regular select is very slow though! It takes 2 1/2 days to unload the
> tabel
> (22.500.000 records)
>
> Does anyone know a faster way to create a flat-file of a table this size?
>
> Eric Lansu
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Received on Wed Jan 10 2001 - 04:47:37 CST