Aleksander Kmetec <[EMAIL PROTECTED]> writes:
> I'm trying to split a table into 2 partitions based on whether a field's 
> value is NULL or NOT NULL, but when I run 
> "EXPLAIN SELECT * FROM tab WHERE version IS NULL" it shows that both 
> partitions are being scanned, not just the one 
> which contains rows where version is null.

> Is this not supported?

Nope, predicate_refuted_by() doesn't cover that particular combination 
at the moment.  The case it does cover was motivated by the thought of
having a regular partitioning into different value classes plus a
partition for NULLs, hence it knows that a test like "version = X"
refutes "version IS NULL".

                        regards, tom lane

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