Re: Freeze avoidance of very large table.

From: Andres Freund <andres(at)anarazel(dot)de>
To: Sawada Masahiko <sawada(dot)mshk(at)gmail(dot)com>
Cc: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com>, Petr Jelinek <petr(at)2ndquadrant(dot)com>, Bruce Momjian <bruce(at)momjian(dot)us>, Robert Haas <robertmhaas(at)gmail(dot)com>, Greg Stark <stark(at)mit(dot)edu>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
Subject: Re: Freeze avoidance of very large table.
Date: 2015-07-13 12:22:50
Message-ID: 20150713122250.GA9518@awork2.anarazel.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On 2015-07-13 21:03:07 +0900, Sawada Masahiko wrote:
> Even If we implement rewriting tool for vm into pg_upgrade, it will
> take time as much as revacuum because it need whole scanning table.

Why would it? Sure, you can only set allvisible and not the frozen bit,
but that's fine. That way the cost for freezing can be paid over time.

If we require terrabytes of data to be scanned, including possibly
rewriting large portions due to freezing, before index only scans work
and most vacuums act in a partial manner the migration to 9.6 will be a
major pain for our users.

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Sawada Masahiko 2015-07-13 12:22:55 Re: Support for N synchronous standby servers - take 2
Previous Message Ildus Kurbangaliev 2015-07-13 12:19:15 Re: RFC: replace pg_stat_activity.waiting with something more descriptive