From: Byron Nikolaidis <byronn@insightdist.com>
To: Jose' Soares Da Silva <sferac@bo.nettuno.it>
Cc: interfaces postgres <pgsql-interfaces@postgreSQL.org>
Subject: Re: [INTERFACES] Re: M$-Access'97 and TIMESTAMPs
Date: Wed, 10 Jun 1998 11:15:49 -0400
Message-ID: <357EA325.6BABF8D4@insightdist.com> (raw)
References: <Pine.LNX.3.96.980610091152.1091B-100000@proxy.bazzanese.com>
Jose' Soares Da Silva wrote:
> My problem is that I need a TIMESTAMP data type defined in M$-Access because
> M$-Access wants it to have best performance when it updates a table via ODBC.
> M$-Access doesn't lock a record being modified, to allow control concurrent
> access to data M$-Access reads again the record to verify if it was modified by
> another user, before update it to database.
> If there's a TIMESTAMP M$-Access verifies only, if this field was modified,
> otherwise it verifies every field of the table, and obviously it is slower.
> I beleave it would very useful if you could add this feature to psqlodbc.
> Thanks, Jose'
>
I have absolutely no problem with adding the postgres 'timestamp' type, in fact, I
already added it.
But, the thing is, the postgres types abstime and datetime, ALREADY map to
SQL_TIMESTAMP!
I think, that this actually has to do with SQLSpecialColumns 'SQL_ROWVER'. Access
checks for this but we don't return anything. SQL_ROWVER is defined as the column(s)
in the specified table, if any, that are automatically updated by the data source when
any value in the row is updated by any transaction (as in SQLBase ROWID or Sybase
TIMESTAMP).
It seems to me, that this suggests that if we had a hidden timestamp column, Access
would use that to verify. I don't believe we have such a column in postgres?
Byron
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To: pgsql-interfaces@postgresql.org
Cc: byronn@insightdist.com, sferac@bo.nettuno.it
Subject: Re: [INTERFACES] Re: M$-Access'97 and TIMESTAMPs
In-Reply-To: <357EA325.6BABF8D4@insightdist.com>
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