| From: | Simon Riggs <simon(at)2ndquadrant(dot)com> |
|---|---|
| To: | "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com> |
| Cc: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: WAL logging of SELECT ... INTO command |
| Date: | 2006-03-21 20:33:50 |
| Message-ID: | 1142973230.24487.501.camel@localhost.localdomain |
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| Lists: | pgsql-patches pgsql-performance |
On Tue, 2006-03-21 at 06:22 -0600, Jim C. Nasby wrote:
> Currently, it appears that SELECT * INTO new_table FROM old_table logs
> each page as it's written to WAL. Is this actually needed? Couldn't the
> database simply log that the SELECT ... INTO statement was executed
> instead? Doing so would likely result in a large performance improvement
> in most installs. Is there no provision for writing anything but data
> page changes (or whole pages) to WAL?
AFAIK it takes the same code path as CREATE TABLE AS SELECT, which
already does exactly what you suggest (except when using PITR).
Best Regards, Simon Riggs
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