Re: Additional current timestamp values

Neil Conway wrote:
> Bruce Momjian wrote:
> > Peter Eisentraut wrote:
> >> The most common complaint that I recall is that current_timestamp 
> >> returns the transaction timestamp rather than the statement timestamp, 
> >> which is what many expect.  How does your patch address that?
> > 
> > No, we believe the standard requires it.
> 
> My copy of SQL 200n has the following to say:
> 
> Annex C, paragraph 16:
> 
>      "The time of evaluation of the CURRENT_DATE, CURRENT_TIME, and
>      CURRENT_TIMESTAMP functions during the execution of an
>      SQL-statement is implementation-dependent."
> 
> 6.31, :
> 
>      (1) The s CURRENT_DATE, CURRENT_TIME,
>      and CURRENT_TIMESTAMP respectively return the current date,
>      current time, and current timestamp; the time and timestamp values
>      are returned with time zone displacement equal to the current
>      default time zone displacement of the SQL-session. [...]
> 
>      (2) Let S be an  that is not generally
>      contained in a . All s
>      that are contained in s that are generally
>      contained, without an intervening  whose subject
>      routines do not include an SQL function, either in S without an
>      intervening  or in an       statement> contained in the  of a trigger
>      activated as a consequence of executing S, are effectively evaluated
>      simultaneously. The time of evaluation of a       function> during the execution of S and its activated triggers is
>      implementation-dependent.

OK, so we just decided transaction timestamp is the most logical value
for CURRENT_TIMESTAMP.  Anyway, this might mean we should have
transaction_timestamp for completeness.  Not sure.

-- 
  Bruce Momjian   http://candle.pha.pa.us
  SRA OSS, Inc.   http://www.sraoss.com

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