On Wed, Mar 4, 2009 at 8:42 PM, Morten Primdahl wrote:
> around while trying to figure out why the first query was slow and the
> subsequent snappy.
Given that you posted that a MySQL restart does not change anything,
but a system restart does, I put my money on the filesystem cache
having buffer
On Mar 4, 2009, at 8:38 PM, Jocelyn Fournier wrote:
Just curious : if there's no index on the column why don't you try
to add one ? That's probably why it takes a lot of time on the
production machine.
Hehe.. I can understand why you ask, I over simplified the question
which was wrong of
and have not been able to pin point why,
as the EXPLAIN looks good and the query is responsive enough when I run
it manually. I was just trying to reproduce that.
The below is after a full restart:
mysql> SET SESSION query_cache_type=off;
Query OK, 0 rows affected (0.00 sec)
mysql> select SQ
I did some tests a couple of weeks ago, using using SQL_NO_CACHE and
clearing out the OS buffer after each query was enough to give me
consistent results that were based on system load rather than cache
efficiency. These two are by far the major factors in my experience,
although no doubt
looks good and the query is responsive
enough when I run it manually. I was just trying to reproduce that.
The below is after a full restart:
mysql> SET SESSION query_cache_type=off;
Query OK, 0 rows affected (0.00 sec)
mysql> select SQL_NO_CACHE count(*) from users where email = &
ql> SET SESSION query_cache_type=off;
Query OK, 0 rows affected (0.00 sec)
mysql> select SQL_NO_CACHE count(*) from users where email = 'hello'
AND 456 = 456;
+--+
| count(*) |
+--+
|0 |
+--+
1 row in set (28.80 sec)
mysql> RESET QUERY CACHE;
Query OK,
If SQL_NO_CACHE is specify, the cache will never be used :
The Query Cache behaviour is quite simple, it uses the exact given query
syntax as a hash to search into the query cache;
it means writing 'select' or 'SELECT' is different. It also means adding
SQL_NO_CACHE will
On Wed, Mar 4, 2009 at 11:23 AM, Thomas Spahni wrote:
> SQL_NO_CACHE means that the query result is not cached. It does not mean
> that the cache is not used to answer the query.
Oh, right, he's looking for this:
SET SESSION query_cache_type=off;
- Perrin
--
MySQL General Maili
On Wed, 4 Mar 2009, Morten wrote:
Hi, I was hoping that using SQL_NO_CACHE would help me bypass the query
cache, but judging from the below it doesn't. What can I do to avoid the
query cache?
Thanks.
Morten
mysql> select count(*) from users where email = 'hello';
+-
On Wed, Mar 4, 2009 at 10:27 AM, Morten wrote:
> Hi, I was hoping that using SQL_NO_CACHE would help me bypass the query
> cache, but judging from the below it doesn't.
You probably just brought the data into the cache and are not hitting
the query cache.
- Perrin
--
MySQL Gene
systems, although Unix stuff is
probably similar.
-Micah
On 03/04/2009 07:27 AM, Morten wrote:
>
> Hi, I was hoping that using SQL_NO_CACHE would help me bypass the
> query cache, but judging from the below it doesn't. What can I do to
> avoid the query cache?
>
> Thanks.
Hi, I was hoping that using SQL_NO_CACHE would help me bypass the
query cache, but judging from the below it doesn't. What can I do to
avoid the query cache?
Thanks.
Morten
mysql> select count(*) from users where email = 'hello';
+--+
| count(*) |
+
learnt more from here.
On Jan 16, 2008 2:31 PM, Dan Nelson <[EMAIL PROTECTED]> wrote:
> In the last episode (Jan 16), mos said:
> > I tried :
> >
> > select SQL_NO_CACHE * from table where col1='abc';
> >
> > which took 800ms the first time it was
In the last episode (Jan 16), mos said:
> I tried :
>
> select SQL_NO_CACHE * from table where col1='abc';
>
> which took 800ms the first time it was executed. The second time it
> was executed it took 0ms. How is that possible if the query is not
> put into th
mos wrote:
I tried :
select SQL_NO_CACHE * from table where col1='abc';
which took 800ms the first time it was executed. The second time it was
executed it took 0ms. How is that possible if the query is not put into
the query cache? Should the query take roughly the same amou
I tried :
select SQL_NO_CACHE * from table where col1='abc';
which took 800ms the first time it was executed. The second time it was
executed it took 0ms. How is that possible if the query is not put into the
query cache? Should the query take roughly the same amount of time?
TIA
TED]
Sent: Thursday, November 16, 2006 8:41 AM
To: Logg, Connie A.
Subject: RE: More info about 40001 SQL_NO_CACHE
Looks like this may have been fixed in 5.0.25 or above, so if it's the same
bug, you're good to go.
http://bugs.mysql.com/bug.php?id=21288
Howard
-Original Message-
mple yet complicated.
Try to find out what software issued that SQL statement and its intended target.
- Original Message -
From: Connie A. Logg <[EMAIL PROTECTED]>
To: mysql@lists.mysql.com
Sent: Wednesday, November 15, 2006 11:18:31 PM GMT-0500 US/Eastern
Subject: More info about 4000
Analyst
Stanford Linear Accelerator Center
ph: 650-926-2879
"Happiness is found along the way, not at the end of the road, and 'IF' is the middle word in life."
Connie,
this is not an error but a normal SQL statement with a hint:
/*!40001 SQL_NO_CACHE */ means that MySQL
, Connie A. [mailto:[EMAIL PROTECTED]
Sent: Wednesday, November 15, 2006 11:41 AM
To: mysql@lists.mysql.com
Subject: SELECT /*!40001 SQL_NO_CACHE */ * FROM `ROUTEDATA` message
I am running mysql version 5.0.24 and am seeing this error when running
mysqldump.
>From what I can find on the web, th
I am running mysql version 5.0.24 and am seeing this error when running
mysqldump.
>From what I can find on the web, this message is generated by an error in the
>mysql code.
Please correct me if I am wrong.
Is this fixed in mysql 5.0.27 ?
Thanks,
Connie Logg, Network Analyst
Stanford Linear
[mailto:[EMAIL PROTECTED]
Sent: Tuesday, April 27, 2004 1:41 PM
To: [EMAIL PROTECTED]
Subject: sql_no_cache
I am trying to turn of the query caching for select queries I am testing
as I would like to rerun the as if they were the first hit.
The query-cache-type = 1.
I am suspicious b/c I run
ECTED]
Subject: sql_no_cache
I am trying to turn of the query caching for select queries I am testing
as I would like to rerun the as if they were the first hit.
The query-cache-type = 1.
I am suspicious b/c I run a query and it takes 12 seconds. I then run
the same query with no changes and it
I am trying to turn of the query caching for select queries I am testing
as I would like to rerun the as if they were the first hit.
The query-cache-type = 1.
I am suspicious b/c I run a query and it takes 12 seconds. I then run
the same query with no changes and it takes .17 seconds.
Anoth
On Tue, 13 Jan 2004, Priyanka Gupta wrote:
> Hi,
>
> I am trying to do some performance analysis by trying different indexing
> schemes and testing how long it takes. To get consistent results, I would
> like to use something like SQL_NO_CACHE. However, the mysqld version that I
&
Hi,
I am trying to do some performance analysis by trying different indexing
schemes and testing how long it takes. To get consistent results, I would
like to use something like SQL_NO_CACHE. However, the mysqld version that I
have installed does not seem to support it..its 4.0.16
Could
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