Skip site navigation (1) Skip section navigation (2)

Re: Questions about HeapTupleHeaderData

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Zdenek Kotala <Zdenek(dot)Kotala(at)Sun(dot)COM>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Questions about HeapTupleHeaderData
Date: 2008-08-21 14:15:36
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers
Zdenek Kotala <Zdenek(dot)Kotala(at)Sun(dot)COM> writes:
> If I understand correctly then for read path (select) tuple is always 
> HeapTuple, because we need support select xmax ... And DatumTuple is 
> used for write path (insert/update) and it is "converted" to HeapTuple 
> in heap_insert/heap_update function.

No, DatumTuple is used for any free-standing composite-type Datum.
Thinking about it as "write path" and "read path" seems to me to
be missing the mark entirely.  In general most tuple-reading code
is supposed to work with either.

			regards, tom lane

In response to

pgsql-hackers by date

Next:From: D'Arcy J.M. CainDate: 2008-08-21 15:57:19
Subject: Proposal: new border setting in psql
Previous:From: Tom LaneDate: 2008-08-21 14:08:33
Subject: Re: About a message when "pg_ctl -w start" failed

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group