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Home -> Community -> Usenet -> c.d.o.server -> Re: Export times: affected by size of table or amount of data?
In article <3769872b.7762822_at_newshost.us.oracle.com>, Thomas Kyte
<tkyte_at_us.oracle.com> writes
>A copy of this was sent to Andy Hardy <aph_at_ahardy.demon.co.uk>
>(if that email address didn't require changing)
>On Tue, 15 Jun 1999 14:28:29 +0100, you wrote:
>
>>Hi,
>>
>>If I declare a 100Mb table with no data, will it export in less time
>>than the same table full of data?
>>
>>I thought that export times were only dependent on the quantity of data
>>stored, but my customer is telling me otherwise...
>>
>>Andy
>
>it'll depend. If the 100mb table HAD data at some point and was deleted from --
>we will scan to the high water mark looking for data. export tends to full scan
>tables -- if a select count(*) against that empty table doesn't come back
>immediately -- neither will export.
OK. So if the table is set-up with a large initial extent and has ever contained some data, a full scan will be done.
Andy
--
Andy Hardy. PGP key available on request