Tom Lane wrote:
Only two of them are logically equivalent. Consider NULL.
Ohhh IS NOT TRUE or IS NOT FALSE also match NULL, I never knew this :)
Even for the first two, assuming equivalence requires hard-wiring an
assumption about the behavior of the bool = bool operator; which is
a
On Thu, 21 Nov 2002, Stephan Szabo wrote:
On Thu, 21 Nov 2002, Christopher Kings-Lynne wrote:
col isn't of the general form indexkey op constant or constant op
indexkey which I presume it's looking for given the comments in
indxpath.c. I'm not sure what the best way to make
Using the famous WAG tech, in your first query the optimizer has to
evaluate monitored for each record to determine its value.
Robert Treat
On Thu, 2002-11-21 at 13:39, Daniele Orlandi wrote:
Are those two syntaxes eqivalent ?
select * from users where monitored;
select * from users where
On Thu, 21 Nov 2002, Daniele Orlandi wrote:
Are those two syntaxes eqivalent ?
select * from users where monitored;
select * from users where monitored=true;
If the answer is yes, the optimimer probably doesn't agree with you :)
That depends on the definition of equivalent. They
Are those two syntaxes eqivalent ?
select * from users where monitored;
select * from users where monitored=true;
If the answer is yes, the optimimer probably doesn't agree with you :)
That depends on the definition of equivalent. They presumably give the
same answer (I'm assuming
On Thu, 21 Nov 2002, Christopher Kings-Lynne wrote:
Are those two syntaxes eqivalent ?
select * from users where monitored;
select * from users where monitored=true;
If the answer is yes, the optimimer probably doesn't agree with you :)
That depends on the definition of
I think his point is that they _should_ be equivalent. Surely there's
something in the optimiser that discards '=true' stuff, like 'a=a'
should be
discarded?
I figure that's what he meant, but it isn't what was said. ;)
col isn't of the general form indexkey op constant or constant op
On Thu, 21 Nov 2002, Christopher Kings-Lynne wrote:
I think his point is that they _should_ be equivalent. Surely there's
something in the optimiser that discards '=true' stuff, like 'a=a'
should be
discarded?
I figure that's what he meant, but it isn't what was said. ;)
col
On Thu, 21 Nov 2002, Christopher Kings-Lynne wrote:
I think his point is that they _should_ be equivalent. Surely there's
something in the optimiser that discards '=true' stuff, like 'a=a'
should be
discarded?
I figure that's what he meant, but it isn't what was said. ;)
col
Not that I see the point of indexing booleans, but hey :)
If one of the values is much more infrequent than the other, you can
probably get a substantial win using a partial index, can't you?
Yes, I thought of the partial index after I wrote that email :)
Chris
col isn't of the general form indexkey op constant or constant op
indexkey which I presume it's looking for given the comments in
indxpath.c. I'm not sure what the best way to make it work would be
given
that presumably we'd want to make col IS TRUE/FALSE use an index at
the
same
On Thu, 21 Nov 2002, Christopher Kings-Lynne wrote:
col isn't of the general form indexkey op constant or constant op
indexkey which I presume it's looking for given the comments in
indxpath.c. I'm not sure what the best way to make it work would be
given
that presumably we'd
Stephan Szabo wrote:
On Thu, 21 Nov 2002, Daniele Orlandi wrote:
Are those two syntaxes eqivalent ?
select * from users where monitored;
select * from users where monitored=true;
If the answer is yes, the optimimer probably doesn't agree with you :)
That depends on the definition of
Daniele Orlandi [EMAIL PROTECTED] writes:
The problem is the opposite... so, effectively, seems that the optimizer
considers monitored and monitored=true as two different expressions...
Check.
The viceversa is analog and we also can see that the syntax monitored
is true is considered
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