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Subject: Re: [SQL] [GENERAL] CURRENT_TIMESTAMP
From: Oliver Elphick <olly@lfix.co.uk>
To: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andrew Sullivan <andrew@libertyrms.info>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>
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On Fri, 2002-10-04 at 01:41, Bruce Momjian wrote:
> Well, let's see what others say.  If no one is excited about the change,
> we can just document its current behavior.  Oh, I see it is already
> documented in func.sgml:
> 
>     It is quite important to realize that
>     <function>CURRENT_TIMESTAMP</function> and related functions all return
>     the time as of the start of the current transaction; their values do not
>     increment while a transaction is running.  But
>     <function>timeofday()</function> returns the actual current time.
> 
> Seems that isn't helping enough to reduce the number of people who are
> surprised by our behavior.  I don't think anyone would be surprised by
> statement time.
> 
> What do others think?

I would prefer that CURRENT_TIME[STAMP] always produce the same time
within a transaction.  If it is changed, it will certainly break one of
my applications, which explicitly depends on the current behaviour.  If
you change it, please provide an alternative way of doing the same
thing.

I can see that the current behaviour might give surprising results in a
long running transaction.  Surprise could be reduced by giving the time
of first use within the transaction rather than the start of the
transaction.

-- 
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight, UK                            
http://www.lfix.co.uk/oliver
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