Re: troubleshooting pointers

Tom Lane wrote:
> Joe Conway <mail(at)joeconway(dot)com> writes:
>
>>With the current SRF patch, in certain circumstances selecting from a
>>VIEW produces "Buffer Leak" warnings, while selecting from the function
>>itself does not. Also the VIEW returns only one of the two expected
>>rows.
>
> The buffer leak suggests failure to shut down a plan tree (ie, no
> ExecutorEnd call). Probably related to not running the VIEW to
> completion, but it's hard to guess at the underlying cause.
>
> Do the plan trees (EXPLAIN display) look the same in both cases?

Yes, but it suffers from the issue you brought up yesterday -- i.e.
EXPLAIN doesn't run from within the function, and EXPLAIN outside the
function (or VIEW which calls it) doesn't show very much:

test=# EXPLAIN SELECT * FROM vw_getfoo;
QUERY PLAN
-----------------------------------------------------------
Function Scan on getfoo (cost=0.00..0.00 rows=0 width=0)
(1 row)

test=# EXPLAIN SELECT * FROM getfoo(1);
QUERY PLAN
-----------------------------------------------------------
Function Scan on getfoo (cost=0.00..0.00 rows=0 width=0)
(1 row)

I found an explaination you gave a while back which sounds like it
explains the problem:
http://archives.postgresql.org/pgsql-bugs/2001-06/msg00051.php

I also confirmed that postquel_end(), which calls ExecutorEnd(), never
gets called for the VIEW case (or the LIMIT case that was pointed out on
an earlier post).

Just now I was looking for a way to propagate the necessary information
to call ExecutorEnd() from ExecEndFunctionScan() in the case that fmgr
doesn't. It looks like I might be able to add a member to the
ExprContext struct for this purpose. Does this sound like the correct
(or at least a reasonable) approach?

Thanks,

Joe