Re: Partitioning and constraint exclusion

First, what is the PostgresSQL version ??????

Next, in postgresql.conf, what is the value of constraint_exclusion ?

On Mon, Sep 7, 2015 at 8:55 AM, Jayadevan M <maymala(dot)jayadevan(at)gmail(dot)com>
wrote:

> Hello ,
>
> I have a parent table and 6 child tables (partitions). The child tables
> have check constraints defined in the form
> CHECK (myuid in (123,456,..)).
> myuid is bigint, the constraints for the 6 child tables are definitely
> mutually exclusive. The number of values in the list ranges from 2-10 for 5
> of the child tables. For the 6th child table, the list is 2500+ elements.
> When I try explain/explain analyze for even a simple query like
>
> select * from parent where myuid in (123,456,789)
>
> the child table with 2500+ elements gets always scanned. I have an index
> on the column and that does get used. But why doesn't the planner just use
> constraint exclusion and not go for the index scan? Anyone faced a similar
> issue?
>
> Thanks,
> Jayadevan
>

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