Subject | RE: [firebird-support] Proper way for copy data from big table |
---|---|
Author | Mark Rotteveel |
Post date | 2015-06-19T14:53:13Z |
On Fri, 19 Jun 2015 14:48:44 +0000, "'Leyne, Sean'
Sean@... [firebird-support]"
<firebird-support@yahoogroups.com> wrote:
don't apply an order by, reading will just be stalled until the next fetch.
Mark
Sean@... [firebird-support]"
<firebird-support@yahoogroups.com> wrote:
>> what is the proper way for copy data from big table to another databasethe
>> if table is bigger then avaiable RAM and we need to do this in one
>> transaction?
>> You know if we do
>> SELECT * FROM SOURCE_TABLE - and table have e.g. 400 000 000 records
>> then retrive it is impossible because of RAM
>
> Actually, a result set will "spill-over" to a temporary sort file, so
> amount of memory in use should not be that bad.As far as I know, it won't spill-over into a temporary sort file if you
don't apply an order by, reading will just be stalled until the next fetch.
Mark