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To: Daniel Roth <dan.c.roth@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: predicate locking 
In-reply-to: <71038fca05061203395e5a2613@mail.gmail.com> 
References: <71038fca05061203395e5a2613@mail.gmail.com>
Comments: In-reply-to Daniel Roth <dan.c.roth@gmail.com>
	message dated "Sun, 12 Jun 2005 18:39:34 +0800"
Date: Sun, 12 Jun 2005 11:04:02 -0400
Message-ID: <23768.1118588642@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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Daniel Roth <dan.c.roth@gmail.com> writes:
> But MSSQL (SQL Server) does predicate locking.

> Places a range lock on the data set, preventing other users from
> updating or inserting rows into the data set until the transaction is
> complete. This is the most restrictive of the four isolation levels.

Range locks are a far cry from general predicate locks.

			regards, tom lane

PS: kindly don't email me privately while posting the same message to
the lists.  You think I have time to answer things twice?