Neil Conway <[EMAIL PROTECTED]> writes:
> Hmm, true. Perhaps then just hacking the hash node so that hash join
> pulls on it twice (the first time for a single tuple, the second time
> for the rest) is the way to go. Since the hash node is essentially an
> implementation detail of hash join, I d
On Thu, Mar 31, 2005 at 12:03:37AM -0500, Tom Lane wrote:
> > Right; I was planning to bail and only do this for inner joins.
>
> Well, for outer joins the optimal strategy is simple: pull from the
> outer query first. If it's empty then you needn't touch the inner
> query at all. Otherwise you
Neil Conway <[EMAIL PROTECTED]> writes:
> I think this tweak would be universally better than the existing code.
Yes, but you miss the point: there's a case where the existing code
isn't good and you aren't improving it. Specifically, where the inner
query has high startup cost and the outer quer
Tom Lane wrote:
One small objection is that we'd lose the ability to separately display
the time spent building the hash table in EXPLAIN ANALYZE output. It's
probably not super important, but might be a reason to keep two plan
nodes in the tree.
Hmm, true. Perhaps then just hacking the hash node
One small objection is that we'd lose the ability to separately display
the time spent building the hash table in EXPLAIN ANALYZE output. It's
probably not super important, but might be a reason to keep two plan
nodes in the tree.
Would a separate hash node help for these kinds of queries in the f
Neil Conway <[EMAIL PROTECTED]> writes:
> ... I'm wondering if there is any value to maintaining the hash
> vs. hash join distinction in the first place.)
One small objection is that we'd lose the ability to separately display
the time spent building the hash table in EXPLAIN ANALYZE output. It's
Is there a reason why the implementation of hash joins uses a separate
"hash" child node? AFAICS that node is only used in hash joins. Perhaps
the intent was to be able to provide a generic "hashing" capability that
could be used by any part of the executor that needs to hash tuples, but
AFAICS
