Re: [HACKERS] Pulling up more complicated subqueries

2017-05-19 Thread Ashutosh Bapat
On Wed, May 17, 2017 at 8:38 PM, Heikki Linnakangas wrote: > > As a final note, I found an interesting paper called "Unnesting Arbitrary > Queries", by Thomas Neumann and Alfons Kemper >

Re: [HACKERS] Pulling up more complicated subqueries

2017-05-17 Thread David Rowley
On 18 May 2017 at 04:30, Robert Haas wrote: > On Wed, May 17, 2017 at 11:08 AM, Heikki Linnakangas wrote: >> That's not a straight semi-join, but we could still turn it into a new kind >> of LEFT-SEMI join. A left-semi join is like a left join, in that it

Re: [HACKERS] Pulling up more complicated subqueries

2017-05-17 Thread Robert Haas
On Wed, May 17, 2017 at 11:08 AM, Heikki Linnakangas wrote: > That's not a straight semi-join, but we could still turn it into a new kind > of LEFT-SEMI join. A left-semi join is like a left join, in that it returns > all rows from the left side, and NULLs for any non-matches.