Re: count on transaction ID

From: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
To: "ddgs" <gsmaths(at)gmail(dot)com>,<pgsql-performance(at)postgresql(dot)org>
Subject: Re: count on transaction ID
Date: 2012-03-12 14:40:45
Message-ID: 4F5DC49D02000025000460F6@gw.wicourts.gov
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ddgs <gsmaths(at)gmail(dot)com> wrote:

> It is a discussion about the transaction ID wraparound in
> PostgreSQL.

Hopefully you've seen this:

http://www.postgresql.org/docs/current/static/routine-vacuuming.html#VACUUM-FOR-WRAPAROUND

> However, what is the fundamental definition if transaction ID.

As the cited page states, it is 32 bits. It is considered a
"circular" number space.

> select * from table where ID=1:10000
> it is consider as one transaction or 10000 transactions.

In SQL it would be a syntax error; it doesn't really mean anything.
And it seems that you may be confused about the difference between
transaction IDs, object IDs, and user-defined ID columns on tables.
What is the "ID=1:10000" syntax supposed to mean?

-Kevin

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