Thread

subselect

Bruce Momjian <maillist@candle.pha.pa.us> — 1998-01-05T05:16:49Z

I was thinking about subselects, and how to attach the two queries.

What if the subquery makes a range table entry in the outer query, and
the query is set up like the UNION queries where we put the scans in a
row, but in the case we put them over/under each other.

And we push a temp table into the catalog cache that represents the
result of the subquery, then we could join to it in the outer query as
though it was a real table.

Also, can't we do the correlated subqueries by adding the proper
target/output columns to the subquery, and have the outer query
reference those columns in the subquery range table entry.

Maybe I can write up a sample of this?  Vadim, would this help?  Is this
the point we are stuck at?

-- 
Bruce Momjian
maillist@candle.pha.pa.us