Re: Statement level triggers

From: "Greg Sabino Mullane" <greg(at)turnstep(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Statement level triggers
Date: 2010-01-20 13:29:23
Message-ID: 853451f146fadd3f32b195b5d1eab90e@biglumber.com
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> What'd be the behavior of a (plpgsql) trigger function when called as
> a statement level trigger?
> Let's say that a statement will involve more than one row.
> The documentation (v8.4.2, "35.1. Overview of Trigger Behavior") says:
>
> "Statement-level triggers do not currently have any way to examine the
> individual row(s) modied by the statement."

It's not clear what you are asking, but statement-level triggers imply
that the actual data (e.g. row changes) are not relevant (or visible)
to the trigger. Thus, it's more of "something" has changed trigger, rather
than a row-level "this stuff" has changed trigger. For example, Bucardo
uses both kinds: the row-level triggers keep track of what rows have
changed, and statement-level triggers which send a NOTIFY to let the
Bucardo daemon know that the table has changed.

- --
Greg Sabino Mullane greg(at)turnstep(dot)com
End Point Corporation http://www.endpoint.com/
PGP Key: 0x14964AC8 201001200828
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8
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