maria-discuss team mailing list archive

[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