thanks for all your feedback it is appreciated

----- Original Message ----- 
From: "Keith Allpress" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, October 12, 2008 6:15 PM
Subject: [phpug] Re: caching pages?


> 
> Using a query cache also has some implications for your code.
> For example if you want to put a read lock on a table you probably need 
> to flush the table
> from the cache because the cache itself doesn't hold locks.
> Keith
> 
>> Hi Mark,
>>
>>   
>>> Does the MySQL query cache actually work? I have heard various things
>>> to the contrary, but haven't actually used it in production, so I
>>> don't know for certain.
>>>     
>>
>> It depends.  The query cache increases the amount of work that has to  
>> be done - reads have to check the cache first and update it after a  
>> miss, and writes have to check and invalidate the cache if necessary.   
>> So there is some overhead there, and obviously the query cache won't  
>> improve the data transfer time back to your app.
>>
>> The queries that work best with the cache are ones that are relatively  
>> expensive to generate, but where the result set's small - like  
>> aggregate queries.  So it really depends on what you're doing.
>>
>> You can check your cache hit rate to get a benchmark of how effective  
>> it is by looking at the status variables: Qcache_hits / (Qcache_hits +  
>> Com_select)
>>
>>
>> Kind regards,
>> James McGlinn
>> __________________________________
>> CTO
>> Eventfinder Limited
>> Suite 106, Heards Building
>> 2 Ruskin Street, Parnell, Auckland 1052
>> Phone: +649 365 2342
>> Mobile: +6421 633 234
>>
>> [EMAIL PROTECTED]  |  www.eventfinder.co.nz
>>
>>
>> >
>>
>>   
> 
> >

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