Indexing Null Values in PostgreSQL

Question

I have a query of the form:

select m.id from mytable m
left outer join othertable o on o.m_id = m.id
    and o.col1 is not null and o.col2 is not null and o.col3         


        

Answer 1

You could try a partial index:

CREATE INDEX idx_partial ON othertable (m_id)
WHERE (col1 is not null and col2 is not null and col3 is not null);

From the docs: http://www.postgresql.org/docs/current/interactive/indexes-partial.html