Re: Data in table changed? - Mailing list pgsql-general

From Karl O. Pinc
Subject Re: Data in table changed?
Date
Msg-id 20040302083921.A31279@mofo.meme.com
Whole thread Raw
In response to Data in table changed?  ("Thomas Holmgren" <thm@regnecentralen.dk>)
List pgsql-general
On 2004.03.02 08:04 Thomas Holmgren wrote:

  I need an efficient way of determining if data in
> a
> table has been changed (either updated, deleted or inserted). Can this
> be achieved without scanning the tables using expensive SQL? (my
> tables
> are _big_!) Is there some way to get a "time for last update" for a
> specific table? Or something similar I can use?

You could always make table of 'last changed' timestamps with
columns of tablename and timestamp.  Then a function which takes
the name of the table and updates the last_changed table with
a timestamp is called from a trigger for insert, update, and
delete of each table.  The CREATE TRIGGER would pass the name
of the table to the function.

Karl <kop@meme.com>
Free Software:  "You don't pay back, you pay forward."
                  -- Robert A. Heinlein

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