Hi, Roberto! On May 24, Roberto Spadim wrote: > Hi guys i'm reading query cache code, and i have some doubts... > mariadb-10.0.1 source: > > 1)PROTOCOL_LOCAL: > at line: 1412 (Query_cache::store_query) > we have this comment: > /* PROTOCOL_LOCAL results are not cached. */ > > what's PROTOCOL_LOCAL ? it's the unix socket? windows pipe? embedded? > memcache? mysql? another thing like this? or it's the internal mariadb > source running queries?
It's not used. Dead code. > 2)the query_size=0 (MDEV-4516) > i was reading at line 1680 > > if (is_disabled() || thd->locked_tables_mode || > thd->variables.query_cache_type == 0) > goto err; > > and line : 1694 > DBUG_ASSERT(query_cache_size != 0); // otherwise cache would be > disabled > > why it's isn't used in query_cache_information plugin? > *check that in line 1680 it test the "query_cache_type" too, * > *in MDEV-4516 report about size=0 we didn't tested this case!!!* query_cache_information plugin uses qc->is_disabled() this should cover all cases. > 3) i was at line 1886: > DBUG_PRINT("qcache", ("\ > long %d, 4.1: %d, bin_proto: %d, more results %d, pkt_nr: %d, \ > CS client: %u, CS result: %u, CS conn: %u, limit: %lu, TZ: 0x%lx, \ > sql mode: 0x%llx, sort len: %lu, conncat len: %lu, div_precision: %lu, \ > def_week_frmt: %lu, in_trans: %d, autocommit: %d", > > is this the "primary key" of the query cache!?!?!?!?!?!?! > could we use a sha1 or another "primary key" method (index [] of the query > in cache + '';'+ 5 bytes of a hash key to compare if the index still with > the same query) > to easly show query entry "number", and allow a "delete from > query_cache_information where key=xxx" function? > > at line 1938 we have this maybe the query position on cache ("primary key > of query cache")?: > DBUG_PRINT("qcache", ("Query have result 0x%lx", (ulong) query)); No, information_schema tables are read-only. Regards, Sergei _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp