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From:Eric Bergen Date:October 3 2011 5:22pm
Subject:Re: 4 minute slow on select count(*) from table - myisam type
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Can you run show processlist in another connection while the select
count(*) query is running and say what the state column is?

On Mon, Oct 3, 2011 at 7:00 AM, Joey L <mjh2000@stripped> wrote:
> this is not a real query on the site - it is just a way i am measuring
> performance on mysql - I do not know if it is such a great way to test.
> Looking for a better way to get a performance read on my site...do you have
> any ?? besides just viewing pages on it.
> thanks
> mjh
>
>
> On Mon, Oct 3, 2011 at 9:58 AM, Andrés Tello <mr.criptos@stripped>
> wrote:
>
>> have you tried
>>
>> select count(yourindex) instead of select count(*) ?
>>
>>
>> On Mon, Oct 3, 2011 at 7:53 AM, Joey L <mjh2000@stripped> wrote:
>>
>>> Thanks for the input -
>>> 1. I will wait 48 hours and see what happens.
>>> 2. can you tell me what are some performance tests I can do to help me
>>> better tune my server ?
>>> 3. I am concerned about this table : | w6h8a_sh404sef_urls
>>> |
>>> MyISAM |      10 | Dynamic    | 8908402 |  
>          174 |  1551178184 |
>>>  281474976710655 |   2410850304 |         0 |
>        8908777 | 2011-09-22
>>> 11:16:03 | 2011-10-02 21:17:20 | 2011-10-02 10:12:04 | utf8_general_ci  
> |
>>>  NULL |                |  
>                          
>       |
>>> what can I do to make it run faster - i did not write the code...but need
>>> to
>>> optimize server to handle this table when it gets larger.  It is used
> for
>>> url re-writes - so it has a lot of urls.
>>> thanks
>>> mjh
>>>
>>> On Mon, Oct 3, 2011 at 12:38 AM, Bruce Ferrell <bferrell@stripped
>>> >wrote:
>>>
>>> >
>>> > The meaning is:
>>> >
>>> > increase max_connections
>>> > reduce wait_timeout
>>> > -- 28800 is wait 8 hours before closing out dead connections
>>> > same for interactive_timeout
>>> >
>>> >
>>> > increase key_buffer_size (> 7.8G) increase join_buffer_size
>>> > -- This keeps mysql from having to run to disk constantly for keys
>>> > -- Key buffer size / total MyISAM indexes: 256.0M/7.8G
>>> > -- You have a key buffer of 256M and 7.8G of keys
>>> >
>>> > join_buffer_size (> 128.0K, or always use indexes with joins)
>>> > Joins performed without indexes: 23576 of 744k queries.
>>> > -- You probably want to look at the slow query log.  Generalize
> the
>>> queries
>>> > and the do an explain on the query.  I have seen instances where a
> query
>>> I
>>> > thought was using an index wasn't and I had to re-write... with help
>>> from
>>> > this list :-)  Thanks gang!
>>> >
>>> >
>>> > increase tmp_table_size (> 16M)
>>> > increase max_heap_table_size (> 16M)
>>> > -- When making adjustments, make tmp_table_size/max_heap_table_size
>>> equal
>>> >
>>> > increase table_cache ( > 1k )
>>> > -- Table cache hit rate: 7% (1K open / 14K opened)
>>> > -- Increase table_cache gradually to avoid file descriptor limits
>>> >
>>> > All of the aside, you need to let this run for at least 24 hours. I
>>> > prefer 48 hours.  The first line says mysql has only been running
> 9
>>> > hours.   You can reset the timeouts interactivly by entering at
> the
>>> > mysql prompt:
>>> >
>>> > set global wait_timeout=<some value>
>>> >
>>> > You can do the same for the interactive_timeout.
>>> >
>>> > Setting these values too low will cause long running queries to abort
>>> >
>>> >
>>> > On 10/02/2011 07:02 PM, Joey L wrote:
>>> > > Variables to adjust:
>>> > > >     max_connections (> 100)
>>> > > >     wait_timeout (< 28800)
>>> > > >     interactive_timeout (< 28800)
>>> > > >     key_buffer_size (> 7.8G)
>>> > > >     join_buffer_size (> 128.0K, or always use
> indexes with joins)
>>> > > >     tmp_table_size (> 16M)
>>> > > >     max_heap_table_size (> 16M)
>>> > > >     table_cache (> 1024)
>>> >
>>> >
>>> > --
>>> > MySQL General Mailing List
>>> > For list archives: http://lists.mysql.com/mysql
>>> > To unsubscribe:    http://lists.mysql.com/mysql?unsub=1
>>> >
>>> >
>>>
>>
>>
>



-- 
Eric Bergen
eric.bergen@stripped
http://www.ebergen.net
Thread
4 minute slow on select count(*) from table - myisam typeJoey L2 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore2 Oct
    • Re: 4 minute slow on select count(*) from table - myisam typeJoey L2 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeBruce Ferrell2 Oct
Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore2 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
    • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
      • Re: 4 minute slow on select count(*) from table - myisam typeBruce Ferrell3 Oct
        • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
          • Re: 4 minute slow on select count(*) from table - myisam typeAndrĂ©s Tello3 Oct
            • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
              • Re: 4 minute slow on select count(*) from table - myisam typeEric Bergen3 Oct
                • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                    • Re: 4 minute slow on select count(*) from table - myisam typeJohnny Withers6 Oct
                      • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                        • Re: 4 minute slow on select count(*) from table - myisam typeJohnny Withers6 Oct
                        • Re: 4 minute slow on select count(*) from table - myisam typeJohan De Meersman6 Oct
                        • Re: 4 minute slow on select count(*) from table - myisam typeRik Wasmus6 Oct
                          • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                            • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore6 Oct
                              • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore6 Oct
                                • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                                  • Re: 4 minute slow on select count(*) from table - myisam typeMichael Dykman6 Oct
Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore6 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
Re: 4 minute slow on select count(*) from table - myisam typeJohnny Withers6 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJohan De Meersman7 Oct
Re: 4 minute slow on select count(*) from table - myisam typeJan Steinman7 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L7 Oct
    • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore7 Oct