Re: queries run twice unless 'parse statements' checked?

> -----Original Message-----
> From: pgsql-odbc-owner(at)postgresql(dot)org
> [mailto:pgsql-odbc-owner(at)postgresql(dot)org] On Behalf Of Johann
> Sent: 07 February 2005 04:20
> To: pgsql-odbc(at)postgresql(dot)org
> Subject: [ODBC] queries run twice unless 'parse statements' checked?
>
> Running PostgreSQL 8.0, client is Visual Basic program using
> ADO, test case
> has one adodc and a bound grid.
>
> Queries involving a 188,000 row table were slow, even when
> query was on
> single value in uniquely keyed index.
>
> Turns out - from checking the plsqlodbc file, it was
> executing the query
> once like I said:
>
> select something from somewhere where thing=value
>
> [returning one row]
>
> then it ran the query again without the where clause [really!]
>
> SELECT something FROM somewhere (The second query had the
> keywords turned
> to upper case, if that helps identify what's going on.)
>
> [returning 188,000 rows]
>
> Naturally, this made things run slowly. I fiddled around and
> eventually
> found that by checking "Parse Statements", this behavior stopped.
>
> Anyway - is it supposed to work this way?

I cannot reproduce this behaviour here using a simple ADO recordset -
but can with the ADODC. My guess is that it is running the query again
to get column definitions (which happens automatically - and doubtless
more efficiently - with parse turned on) so that it can figure out how
to build update queries etc.

Regards, Dave,