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Date: Wed, 26 Dec 2007 10:11:03 -0800 (PST)
From: chester c young <chestercyoung@yahoo.com>
Subject: Re: Advice for generalizing trigger functions
To: Richard Broersma Jr <rabroersma@yahoo.com>
Cc: sql pgsql <pgsql-sql@postgresql.org>
In-Reply-To: <781842.52422.qm@web31813.mail.mud.yahoo.com>
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--- Richard Broersma Jr <rabroersma@yahoo.com> wrote:

> I've created quite a few functions that log modifications to various
> history tables. (the history table has the same name as the base
> table but is prefixed by the 'History.' schema.) The only difference
> between functions I can find is the table name.

the problem is that prepared code is referenced by oid, not name.  so
any structural references need to by dynamic.

what I do for change log is to have one change log table with table_id
and column_id attributes that refer by to my internal meta_table and
meta_column tables.  this always works and is in the end, I have found,
a bit more flexible, allowing you to search for changed columns, for
example.

but I still generate the change triggers.  in this case from in my
meta_table and meta_column tables I note which table/columns I want
changes tracked.  those can be changed at any time, but the change log
triggers need to be recompiled.


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