select * from attributes_table where id in (select id from
attributes where (name='obsid') and (value='oid00066'));
Can you convert it into a join? 'where in' clauses tend to slow pgsql
down.
--
Mike Nolan
---(end of broadcast)---
TIP 6
,
even if you move that field into a separate table.
--
Mike Nolan
---(end of broadcast)---
TIP 7: don't forget to increase your free space map settings
.
The same query a while later might respond quickly again.
I'm not sure where to look for the delay, either, and it is intermittent
enough that I'm not even sure what monitoring techniques to use.
--
Mike Nolan
---(end of broadcast)---
TIP 8: explain
and were fixed by a better implementation. Perhaps something like
that is causing what you are seeing.
My web app traps double-clicks in javascript and ignores all but the first one.
That's because some of the users have mice that give double-clicks even
when they only want one click.
--
Mike Nolan
that converts columns to something you can
store in a common log table. (I've not found a way to do this without
inserting one row for each column being logged, though.)
--
Mike Nolan
---(end of broadcast)---
TIP 7: don't forget to increase
insert command? I can get
significantly higher rates on my devel machine if the inserts are
bundled into transactions of reasonable length.
That's with autocommit on. If I do it as a single transaction block,
it takes about 6.5 seconds, which is about 4200 transactions/second.
--
Mike Nolan
I'm running postgres 8.0.7, and I've got a table of orders with about
100,000 entries. I want to just look at the new orders, right now 104 of
them.
EXPLAIN ANALYZE
SELECT
order_id
FROM
orders
WHERE
order_statuses_id = (SELECT id FROM order_statuses WHERE id_name
=
Questions:
* What can I do to reduce the estimated row count on the query?
* Why does clustering drive down the estimated cost for the index scan
so much? Does a change in correlation from .72 to 1 make that much of
a difference?
* Can I convince my query planner to index scan without
Tom Lane wrote:
The first-order knob for tuning indexscan vs seqscan costing is
random_page_cost. What have you got that set to?
This is currently at the default of 4. All of my other planner cost
constants are at default values as well. Dropping it to 1 drops the
estimated cost by a
Tom Lane wrote:
Nolan Cafferky [EMAIL PROTECTED] writes:
But, I'm guessing that random_page_cost = 1 is not a realistic value.
Well, that depends. If all your data can be expected to fit in memory
then it is a realistic value. (If not, you should be real careful not
to make
AND f.p_Modified_Date =
g.p_LastModified))
-- Luckys
--
Nolan Cafferky
Software Developer
IT Department
RBS Interactive
[EMAIL PROTECTED]
---(end of broadcast)---
TIP 1: if posting/reading through Usenet, please send an appropriate
the instructions from there.
--
Nolan Cafferky
Software Developer
IT Department
RBS Interactive
[EMAIL PROTECTED]
it is a later kernel. Can you clarify which
3.X kernels are good to use and which are not?
--
Mike Nolan
On Fri, Jun 12, 2015 at 4:52 PM, David G. Johnston
david.g.johns...@gmail.com wrote:
On Fri, Jun 12, 2015 at 4:37 PM, Michael Nolan htf...@gmail.com wrote:
The only thing I can come up that's happened since last night was that we
ran the nightly vacuum analyze on that database, but I did
.
The parameters I was working with were:
effective_cache_size
shared_buffers
temp_buffers
work_mem
maintenance_work_mem
Looking at the free command, I see a lot more memory being used for
buffer/cache today. (Centos 7.)
--
Mike Nolan
no...@tssi.com
challenging, because it's going to be
dependent on the specific table and the contents of the row, among other
things.
--
Mike Nolan
no...@tssi.com
, even if the index keys are not
changing. That's because any pending transactions still need to be able to
find the 'old' data, while new transactions need to be able to find the
'new' data. And ACID also means an update is essentially a
delete-and-insert.
--
Mike Nolan
with filesystem (or database) corruption anyway.
- Heikki
The sad fact is that MANY drives (ssd as well as spinning) lie about their
fsync status.
--
Mike Nolan
er virtualizers?
--
Mike Nolan
19 matches
Mail list logo
