Re: BUG #16549: "CASE" not work properly , the function works properly on PostgreSQL 9.6.8 - Mailing list pgsql-bugs

From Tom Lane
Subject Re: BUG #16549: "CASE" not work properly , the function works properly on PostgreSQL 9.6.8
Date
Msg-id 57211.1595456246@sss.pgh.pa.us
Whole thread Raw
In response to Re: BUG #16549: "CASE" not work properly , the function works properly on PostgreSQL 9.6.8  (Pavel Stehule <pavel.stehule@gmail.com>)
Responses Re: BUG #16549: "CASE" not work properly , the function works properly on PostgreSQL 9.6.8
List pgsql-bugs
Pavel Stehule <pavel.stehule@gmail.com> writes:
> What is interesting - it fails only when the subquery is in CASE condition
> expression. If is somewhere else, then it doesn't fail

If eval_const_expressions can simplify the CASE test condition itself
to constant-true or constant-false, then it throws away the unreachable
result expression(s) without const-simplifying them.  So even if there
would have been a run-time error there, you don't see it.

Of course the error can only happen because we're trying to generate a
custom plan for the expression (with plpgsql variable values inserted
as constants not params).  That's a bit silly in this example, but
it wouldn't happen if there weren't a sub-SELECT in the expression.
That forces use of the full planner and plancache machinery.

            regards, tom lane



pgsql-bugs by date:

Previous
From: "David G. Johnston"
Date:
Subject: Re: BUG #16550: Problem with pg_service.conf
Next
From: Tom Lane
Date:
Subject: Re: BUG #16476: pgp_sym_encrypt_bytea with compress-level=6 : Wrong key or corrupt data