2008/8/6 Tom Lane [EMAIL PROTECTED]:
Gregory Stark [EMAIL PROTECTED] writes:
Tom Lane [EMAIL PROTECTED] writes:
There are still two places in the system that hard-wire the use of
sorting for duplicate elimination:
* Set operations (UNION/INTERSECT/EXCEPT)
Egads. Are you thinking to
Tom Lane wrote:
I've pretty much finished the project I got a bee in my bonnet about
last week, which is to teach SELECT DISTINCT how to (optionally) use
hashing for grouping in the same way that GROUP BY has been able to do
for awhile.
There are still two places in the system that hard-wire
Hitoshi Harada [EMAIL PROTECTED] writes:
In my patch nodeWindow.c, some functions reach for its parent state
node to get info of sort keys by using fcinfo-context. This works but
is completely ugly.
Isn't that the same thing nodeAgg does: pass its AggState to aggregate
functions? I don't see
2008/8/6 Tom Lane [EMAIL PROTECTED]:
Hitoshi Harada [EMAIL PROTECTED] writes:
In my patch nodeWindow.c, some functions reach for its parent state
node to get info of sort keys by using fcinfo-context. This works but
is completely ugly.
Isn't that the same thing nodeAgg does: pass its
Hitoshi Harada [EMAIL PROTECTED] writes:
Correct. I learned that method from nodeAgg. What I meant was that
window functions reach for plan node and its sort keys through
winstate-ss.ps. The mechanism is not ugly but some macros or exposed
API seem more comfortable, especially if thinking
I wrote:
... For INTERSECT/EXCEPT (with or without ALL),
you really need to maintain counters in each hashtable entry so you know
how many matching rows you got from each side of the set operation.
So it'd be necessary to either duplicate a large chunk of nodeAgg.c, or
make that code handle
I've pretty much finished the project I got a bee in my bonnet about
last week, which is to teach SELECT DISTINCT how to (optionally) use
hashing for grouping in the same way that GROUP BY has been able to do
for awhile.
There are still two places in the system that hard-wire the use of
sorting
Sounds very much like 80% 20% story. 80% that was easy to do is done and now
20% that is complex and progress is slow is left to be done. Sounds very
familiar from the comment in plan cache invalidation :)
On Tue, Aug 5, 2008 at 5:51 PM, Tom Lane [EMAIL PROTECTED] wrote:
I've pretty much
Tom Lane [EMAIL PROTECTED] writes:
I've pretty much finished the project I got a bee in my bonnet about
last week, which is to teach SELECT DISTINCT how to (optionally) use
hashing for grouping in the same way that GROUP BY has been able to do
for awhile.
There are still two places in the
Gregory Stark [EMAIL PROTECTED] writes:
Tom Lane [EMAIL PROTECTED] writes:
There are still two places in the system that hard-wire the use of
sorting for duplicate elimination:
* Set operations (UNION/INTERSECT/EXCEPT)
Egads. Are you thinking to reimplement them more in line with the way
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