Excerpts from Tom Lane's message of mar jun 08 18:35:00 -0400 2010:
> But none of this accomplishes a damn thing towards the original goal,
> which was to avoid an extra disk write associated with freezing (not
> to mention an extra write for setting the transaction-committed hint
> bit). Setting a bit is no cheaper from that standpoint than changing
> the xmin field.
... unless the bit is outside the page itself -- so we get back to the
idea of a freeze map.
--
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
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