To: "Tom Lane" <tgl@sss.pgh.pa.us>
Cc: <pgsql-hackers@postgreSQL.org>
Subject: Re: Representation of redirected line pointers in HOT
In-Reply-To: <25006.1189621802@sss.pgh.pa.us> (Tom Lane's message of "Wed\,
	12 Sep 2007 14\:30\:02 -0400")
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References: <25006.1189621802@sss.pgh.pa.us>
From: Gregory Stark <stark@enterprisedb.com>
Organization: EnterpriseDB
Date: Wed, 12 Sep 2007 23:29:49 +0100
Message-ID: <877imvh602.fsf@oxford.xeocode.com>
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"Tom Lane" <tgl@sss.pgh.pa.us> writes:

> 	LP_UNUSED	0
> 	LP_NORMAL	1
> 	LP_REDIRECT	2
> 	LP_DEAD		3

> This seems hardly any uglier than the way the code stands today, and
> certainly a lot less ugly than what the current HOT patch proposes.
>
> Comments?

If I understand correctly this still leaves open the possibility of
implementing in the future "quick pruning" as we've been speculating about. We
could represent that with a line pointer which is LP_DEAD but still has a
length and offset. I'm not sure we need to do it now but I'll be glad if we
aren't foreclosing the possibility.

These kinds of rethinks are typical of the tension between someone writing a
patch to submit for review, where they often want to keep the lines of code
changed to a minimum to avoid conflicts and to avoid giving reviewers extra
code to read which, and normal code maintenance. 


-- 
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com