2010/11/15 Humair Mohammed :
> I have 2 tables with a 200,000 rows of data 3 character/string columns ID,
> Question and Response. The query below compares the data between the 2
> tables based on ID and Question and if the Response does not match between
> the left table and the right table it ide
On 16/11/10 09:14, Humair Mohammed wrote:
I have 2 tables with a 200,000 rows of data 3 character/string columns ID,
Question and Response. The query below compares the data between the 2 tables
based on ID and Question and if the Response does not match between the left
table and the right ta
Hi
> SQL Server 2008 R2 Query
> select t1.id from table1 t1 inner join table2 t2 on t1.id = t2.id
> and t1.question = t2.question and isnull(t1.response,'ISNULL') <>
> isnull(t2.response,'ISNULL')
>
> Postgres 9.1 Query
> select t1.id from table1 t1 inner join table2 t2 on t1.id = t2.id
> and t
I have 2 tables with a 200,000 rows of data 3 character/string columns ID,
Question and Response. The query below compares the data between the 2 tables
based on ID and Question and if the Response does not match between the left
table and the right table it identifies the ID's where there is a
> I've changed default_statistics_target to 1 and I think that is a
> reason.
> That's certainly going to cost you something, but this seems like a mighty
large slowdown, especially for a non-join query. What datatype is te.idtr,
anyway?
Integer not null and primary key of t_positions tab
=?iso-8859-2?Q?Artur_Zaj=B1c?= writes:
> I've changed default_statistics_target to 1 and I think that is a
> reason.
That's certainly going to cost you something, but this seems like a
mighty large slowdown, especially for a non-join query. What datatype
is te.idtr, anyway?
2010/11/15 Artur Zając :
> Why there is so big difference between explain analyze (0.710 ms) and
> real execution time (3309 ms)? Any suggestions?
> Could it be that it takes a long time to plan for some reason? How fast
is a plain EXPLAIN?
Yes! That is it :) Planning is painful. I'm so stupi
2010/11/15 Artur Zając :
> Why there is so big difference between explain analyze (0.710 ms) and real
> execution time (3309 ms)? Any suggestions?
Could it be that it takes a long time to plan for some reason? How
fast is a plain EXPLAIN?
What happens if you start up psql, turn on \timing, and t
On Mon, Nov 15, 2010 at 2:27 PM, Andy Colson wrote:
> On 11/15/2010 9:06 AM, Robert Haas wrote:
>>
>> In 9.1, I'm hopeful that we'll have unlogged tables, which will even
>> better than turning these parameters off, and for which I just posted
>> a patch to -hackers. Instead of generating WAL and
On 11/15/2010 9:06 AM, Robert Haas wrote:
In 9.1, I'm hopeful that we'll have unlogged tables, which will even
better than turning these parameters off, and for which I just posted
a patch to -hackers. Instead of generating WAL and writing WAL to the
OS and then NOT trying to make sure it hits t
[Tom Lane]
> EXPLAIN ANALYZE doesn't account for all of the runtime involved. In
> this case, I'd bet that session startup/shutdown is a big part of the
> difference.
The session startup/shutdown should be the same for the real SQL and
the broken SQL, shouldn't it?
[Artur Zając]
> time psql -c
> EXPLAIN ANALYZE doesn't account for all of the runtime involved. In this
case, I'd bet that session startup/shutdown is a big part of the difference.
>
> regards, tom lane
Does session startup/shutdown depend on tables used in query? Some simpler
query:
time psql -c 'e
=?iso-8859-2?Q?Artur_Zaj=B1c?= writes:
> Why there is so big difference between explain analyze (0.710 ms) and real
> execution time (3309 ms)?
EXPLAIN ANALYZE doesn't account for all of the runtime involved. In
this case, I'd bet that session startup/shutdown is a big part of the
difference.
On Fri, Nov 5, 2010 at 8:12 AM, Jon Nelson wrote:
> On Fri, Nov 5, 2010 at 7:08 AM, Guillaume Cottenceau wrote:
>> Marti Raudsepp writes:
>>
>>> On Fri, Nov 5, 2010 at 13:32, A B wrote:
I was just thinking about the case where I will have almost 100%
selects, but still needs something
I have some simple query (executed with time command):
time psql -c 'explain analyze SELECT te.idt FROM t_positions AS te JOIN
t_st AS stm ON (te.idt=stm.idt AND 4=stm.idm) WHERE te.idtr IN (347186)'
QUERY
PLAN
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