From: | Rene Pijlman <rene(at)lab(dot)applinet(dot)nl> |
---|---|
To: | Jeroen van Vianen <jeroen(dot)van(dot)vianen(at)satama(dot)com> |
Cc: | pgsql-jdbc(at)postgresql(dot)org |
Subject: | Re: [HACKERS] JDBC pg_description update needed for CVS tip |
Date: | 2001-09-09 12:58:40 |
Message-ID: | 1gpmpt8k3smepmrscaj8afoskacq6r51ri@4ax.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers pgsql-jdbc pgsql-patches |
On Sun, 09 Sep 2001 14:48:41 +0200, you wrote:
>It is of course a performance improvement if it uses only 1 SQL statement
>rather than N+1 with N being the number of columns reported. E.g. if you
>list all columns of all tables in a big database, this would be a huge win.
I think that can only be decided by measurement.
What you're saying is:
1 * c1 < (N + 1) * c2
but that can only be decided if we know c1 and c2 (meaning: the
execution times of two different queries, including round trip
overhead).
That doesn't mean I'm opposed to the change, on the contrary. As
a rule, I find a complex SQL statement more elegant than the
same 'algorithm' in procedural code. But in this case I wasn't
sure how to construct it.
Regards,
René Pijlman <rene(at)lab(dot)applinet(dot)nl>
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Eisentraut | 2001-09-09 13:25:17 | Re: [JDBC] NULLs and sort order |
Previous Message | Rene Pijlman | 2001-09-09 12:50:35 | NULLs and sort order |
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Eisentraut | 2001-09-09 13:25:17 | Re: [JDBC] NULLs and sort order |
Previous Message | Rene Pijlman | 2001-09-09 12:50:35 | NULLs and sort order |
From | Date | Subject | |
---|---|---|---|
Next Message | Rene Pijlman | 2001-09-09 14:22:28 | Fix DatabaseMetaDataTest in JDBC test suite |
Previous Message | Jeroen van Vianen | 2001-09-09 12:48:41 | Re: [HACKERS] JDBC pg_description update needed for CVS |