# It'd be helpful if you could send mails in text format, not HTML. From: David G. Johnston <david.g.johns...@gmail.com> > For this case the fundamental feature that would seem to be required is an > ability for a transaction commit to return only after the system has ensured > that all of the new pages added to the relation during the scope of the > transaction have made it to disk. Something like: > > BEGIN UNLOGGED TRANSACTION FOR table1, table2; > -- locking probably allows reads, definitely disallows concurrent writes, to > the named tables > -- Disallow updates and deletes, do not use dead tuple space, for the tables > named. Should be able to do normal stuff for other tables? > -- Always create new pages > COPY TO table1; > COPY TO table2; > COMMIT; -- wait here until data files for table1 and table2 are completely > written and the transaction alive flag is committed to the WAL. > > I suppose the above could be written "BEGIN UNLOGGED TRANSACTION FOR ALL > TABLES" and you'd get the initial database population optimization capability. > > If the commit doesn't complete all of the newly created pages are junk. > Otherwise, you have a crash-recoverable state for those tables as regards > those specific pages.
As Steven-san said, I don't want to go this complicated direction. Plus, putting my feet in the user's shoes, I want to try to avoid introducing a new SQL syntax for this kind of performance boost, which requires applications and maintenance scripts and testing. Regards Takayuki Tsunakawa
