On Mon, Jan 5, 2009 at 11:40 PM, Tom Lane t...@sss.pgh.pa.us wrote:
Robert Haas robertmh...@gmail.com writes:
While looking at a complex query that is being poorly planned by
PostgreSQL 8.2.9, I discovered that any non-trivial CASE...WHEN
expression seems to produce a selectivity estimate of
Robert Haas robertmh...@gmail.com writes:
Well, presumably CASE WHEN expr1 THEN constant1 WHEN expr2 THEN
constant2 WHEN expr3 THEN constant3 ... END = constantn could
be simplified to exprn.
Not without breaking the order-of-evaluation guarantees. Consider
case when x=0 then 0 when
While looking at a complex query that is being poorly planned by
PostgreSQL 8.2.9, I discovered that any non-trivial CASE...WHEN
expression seems to produce a selectivity estimate of 0.005. This
also happens on HEAD.
psql (8.4devel)
Type help for help.
head=# create table tenk (c) as select
Robert Haas robertmh...@gmail.com writes:
While looking at a complex query that is being poorly planned by
PostgreSQL 8.2.9, I discovered that any non-trivial CASE...WHEN
expression seems to produce a selectivity estimate of 0.005.
If you have an idea for a non-silly estimate, feel free to
