From: Alvaro Herrera <alvherre@commandprompt.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Steve Singer <ssinger@ca.afilias.info>
Cc: PostgreSQL-development Hackers <pgsql-hackers@postgresql.org>
Subject: Re: skip WAL on COPY patch
Date: Tue, 23 Aug 2011 17:20:24 -0300
Message-ID: <1314130747-sup-4856@alvh.no-ip.org> (raw)
In-Reply-To: <CA+TgmoZj_kYAGJvfU0Y6tr2AUSipHQeSsr9pEPS_o5-CmjBLkw@mail.gmail.com>
References: <4E53E7D5.6030808@ca.afilias.info>
<1739.1314126320@sss.pgh.pa.us>
<CA+TgmoZj_kYAGJvfU0Y6tr2AUSipHQeSsr9pEPS_o5-CmjBLkw@mail.gmail.com>
Excerpts from Robert Haas's message of mar ago 23 17:08:50 -0300 2011:
> What I think would be really interesting is a way to make this work
> when the table *isn't* empty. In other words, have a COPY option that
> (1) takes an exclusive lock on the table, (2) writes the data being
> inserted into new pages beyond the old EOF, and (3) arranges for crash
> recovery or transaction abort to truncate the table back to its
> previous length. Then you could do fast bulk loads even into a table
> that's already populated, so long as you don't mind that the table
> will be excusive-locked and freespace within existing heap pages won't
> be reused.
It seems to me this would be relatively simple if we allowed segments
that are not a full GB in length. That way, COPY could write into a
whole segment and "attach" it to the table at commit time (say, by
renaming).
--
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
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Cc: alvherre@commandprompt.com, robertmhaas@gmail.com, tgl@sss.pgh.pa.us, ssinger@ca.afilias.info
Subject: Re: skip WAL on COPY patch
In-Reply-To: <1314130747-sup-4856@alvh.no-ip.org>
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