Re: Inserting heap tuples in bulk in COPY
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2011-09-25T16:01:36Z
Lists: pgsql-hackers
On Wed, Sep 14, 2011 at 6:52 AM, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> wrote: >> Why do you need new WAL replay routines? Can't you just use the existing >> XLOG_HEAP_NEWPAGE support? >> >> By any large, I think we should be avoiding special-purpose WAL entries >> as much as possible. > > I tried that, but most of the reduction in WAL-size melts away with that. > And if the page you're copying to is not empty, logging the whole page is > even more expensive. You'd need to fall back to retail inserts in that case > which complicates the logic. Where does it go? I understand why it'd be a problem for partially filled pages, but it seems like it ought to be efficient for pages that are initially empty. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company