maria-discuss team mailing list archive

[kentoku <kentokushiba@xxxxxxxxx>]

Hi Roberto,

> nice Colin, I read manual and got this doubt, about the query_cache option
>
> all queries have sql_cache, or just queries that should be cached?
> for example...
>
> (1)mysql user -> (2)mysql database with spider -> (3)external database
> considering at (1 session) and (2 global), spider query_cache = 1 (sql_cache
> option is passed.)
>
> if (1) send: SELECT SQL_NO_CACHE * FROM spider_table   (should not be
> cached)
> (2) will send to (3):  SELECT SQL_CACHE * FROM external_spider_table
> (the wrong option)
>  or : SELECT SQL_NO_CACHE * FROM spider_table  ?   (the right option)

Spider's query_cache option is option for each Spider table. It works
adding SQL_CACHE and SQL_NO_CACHE statically, and it does not use
SQL_CACHE and SQL_NO_CACHE option from user query.

> maybe a "3" should be created? use SQL_CACHE option from user query?

I think it is better for creating another option for using SQL_CACHE
option from user query rather than creating "3", because these options
can be combined.
I'll try to create it, if you need it!

Thanks,
Kentoku


2014-05-30 23:24 GMT+09:00 Roberto Spadim <roberto@xxxxxxxxxxxxx>:
> nice Colin, I read manual and got this doubt, about the query_cache option
>
> all queries have sql_cache, or just queries that should be cached?
> for example...
>
> (1)mysql user -> (2)mysql database with spider -> (3)external database
> considering at (1 session) and (2 global), spider query_cache = 1 (sql_cache
> option is passed.)
>
> if (1) send: SELECT SQL_NO_CACHE * FROM spider_table   (should not be
> cached)
> (2) will send to (3):  SELECT SQL_CACHE * FROM external_spider_table
> (the wrong option)
>  or : SELECT SQL_NO_CACHE * FROM spider_table  ?   (the right option)
>
>
> maybe a "3" should be created? use SQL_CACHE option from user query?
>
>
>
>
> 2014-05-30 8:25 GMT-03:00 Colin Charles <colin@xxxxxxxxxxx>:
>
>>
>> On 29 May 2014, at 10:23, Roberto Spadim <roberto@xxxxxxxxxxxxx> wrote:
>>
>> > Hi guys! I'm with a doubt, spider engine don't allow query cache right?
>> > But does it use sql_cache sql_no_cache when possible?
>> >
>>
>> spider has a table parameter called query_cache that sends query from
>> spider to remote server - see:
>> https://mariadb.com/kb/en/spider-table-system-variables/#query_cache
>> Default is 0, that is no query cache when a select is issued on a remote
>> server
>> =1 passes sql_cache - result can be cached
>> =2 sql_no_cache is passed - query result not cached
>> that's all documented:
>> http://dev.mysql.com/doc/refman/5.5/en/query-cache-in-select.html
>>
>> I notice that in this article, https://mariadb.com/kb/en/query-cache/, the
>> limitations do state: "      • The query cache is not used by the Spider
>> storage engine (amongst others)."
>>
>> And then we have this article,
>> https://mariadb.com/kb/en/spider-feature-matrix/ that also states spider
>> supports the query cache - "Query Cache tuning per table of the on remote
>> backend" - Yes
>>
>> So, docs need to be clearer/in sync, since spider can't use the query
>> cache on a spider node, but it can on a remote server
>> --
>> Colin Charles, Chief Evangelist, SkySQL - The MariaDB Company
>> blog: http://bytebot.net/blog/| t: +6-012-204-3201 | Skype: colincharles
>>
>
>
>
> --
> Roberto Spadim
> SPAEmpresarial
> Eng. Automação e Controle
>
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