Tom Lane wrote:
...
I think the reason this is popping to the top of the runtime is that the
joins are so wide (an average of ~85 columns in a join tuple according
to the numbers above). Because there are lots of variable-width columns
involved, most of the time the fast path for field access does
Miroslav Šulc wrote:
Tom Lane wrote:
...
I think the reason this is popping to the top of the runtime is that the
joins are so wide (an average of ~85 columns in a join tuple according
to the numbers above). Because there are lots of variable-width columns
involved, most of the time the fast path
Tom Lane wrote:
I wrote:
Since ExecProject operations within a nest of joins are going to be
dealing entirely with Vars, I wonder if we couldn't speed matters up
by having a short-circuit case for a projection that is only Vars.
Essentially it would be a lot like execJunk.c, except able to cope
Tom Lane wrote:
=?windows-1250?Q?Miroslav_=8Aulc?= <[EMAIL PROTECTED]> writes:
As there are a lot of varchar(1) in the AdDevicesSites table, wouldn't
be helpful to change them to char(1)? Would it solve the variable-width
problem at least for some fields and speed the query up?
No, becaus
=?windows-1250?Q?Miroslav_=8Aulc?= <[EMAIL PROTECTED]> writes:
> Tom Lane wrote:
>> Actually, we already had a pending patch (from Atsushi Ogawa) that
>> eliminates that particular O(N^2) behavior in another way. After
>> applying it, I get about a factor-of-4 reduction in the runtime for
>> Miros
=?windows-1250?Q?Miroslav_=8Aulc?= <[EMAIL PROTECTED]> writes:
> As there are a lot of varchar(1) in the AdDevicesSites table, wouldn't
> be helpful to change them to char(1)? Would it solve the variable-width
> problem at least for some fields and speed the query up?
No, because char(1) isn't p
I wrote:
> Since ExecProject operations within a nest of joins are going to be
> dealing entirely with Vars, I wonder if we couldn't speed matters up
> by having a short-circuit case for a projection that is only Vars.
> Essentially it would be a lot like execJunk.c, except able to cope
> with two
=?windows-1250?Q?Miroslav_=8Aulc?= <[EMAIL PROTECTED]> writes:
>> Is the data confidential? If you'd be willing to send me a pg_dump
>> off-list, I'd like to replicate this test and try to see where the time
>> is going.
>>
> Thank you very much for your offer. The data are partially confidental
