RE: Portal destination issue: binary vs normal cursors

Does this mean there should be a regression test for binary cursors then...?

Chris

> -----Original Message-----
> From: pgsql-hackers-owner@postgresql.org
> [mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Tom Lane
> Sent: Saturday, 11 August 2001 4:19 AM
> To: Jan Wieck
> Cc: pgsql-hackers@postgresql.org
> Subject: [HACKERS] Portal destination issue: binary vs normal cursors
>
>
> Jan,
>
> I discovered yesterday that DECLARE BINARY CURSOR was broken in CVS tip:
> when you do a FETCH from a binary cursor, you get back ASCII data.
>
> The problem seems to have been induced by your patch for SPI cursor
> support, specifically commands/command.c version 1.128: what had been
>     if (dest == None)
>         override portal's destination with requested dest
> became
>     if (dest != queryDesc->dest)
>         override portal's destination with requested dest
>
> Now a FETCH always passes the standard output destination, normally
> Remote, and so this breaks binary cursors which have dest =
> RemoteInternal and need to stick to that.
>
> I changed the code to look like this:
>
>     /*
>      * If the requested destination is not the same as the query's
>      * original destination, make a temporary QueryDesc with the proper
>      * destination.  This supports MOVE, for example, which will pass in
>      * dest = None.
>      *
>      * EXCEPTION: if the query's original dest is RemoteInternal (ie, it's
>      * a binary cursor) and the request is Remote, we do NOT override the
>      * original dest.  This is necessary since a FETCH command will pass
>      * dest = Remote, not knowing whether the cursor is binary or not.
>      */
>     if (dest != queryDesc->dest &&
>         !(queryDesc->dest == RemoteInternal && dest == Remote))
>     {
>     ... override
>
> This makes binary cursors work again, and it didn't break the regression
> tests, but I thought you should take a look at it.  I don't know what
> aspect of SPI cursors led you to make the original change, so maybe this
> version isn't right for SPI cursors.
>
>             regards, tom lane
>
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