Re: Wishes for PostgreSQL 6.4 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Wishes for PostgreSQL 6.4
Date
Msg-id 9047.908466707@sss.pgh.pa.us
Whole thread Raw
In response to Wishes for PostgreSQL 6.4  (Constantin Teodorescu <teo@flex.ro>)
List pgsql-hackers
Constantin Teodorescu <teo@flex.ro> writes:
> It's there something "Libpgtcl now gets async notifies from libpq(Tom)".
> What means that ? Is there something that could improve PgAccess ?

If you want to listen for notifies, you just have to do "pg_listen".
The bit of code you specify is automatically executed from the Tcl idle
loop whenever a matching notify message arrives, just like button
callbacks and such.  The old "pg_notifies" (sp?) command is not needed
anymore.

> For the moment, pg_select is issuing a "select" statement to backend IS
> WAITING FOR ALL DATA TO COME, and then process the tcl loop.

We speculated a while back about extending PQgetResult to be able to
return partial result sets, say by specifying an upper limit on the
number of tuples per result set.  (Setting the upper limit to be one,
as you imply, is probably not very efficient ... I'd guess a few dozen
tuples per cycle might be reasonable.)  Once that was done pg_select
could be rewritten to make use of it.  It's not going to happen for
6.4, obviously.  Maybe for 6.5.

            regards, tom lane

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