To find theMIN()orMAX()value for a specific indexed columnkey_col. This is optimized by a preprocessor that checks whether you are usingWHEREkey_part_N=constanton all key parts that occur beforekey_colin the index. In this case, MySQL does a single key lookup for eachMIN()orMAX()expre...
To find theMIN()orMAX()value for a specific indexed columnkey_col. This is optimized by a preprocessor that checks whether you are usingWHEREkey_part_N=constanton all key parts that occur beforekey_colin the index. In this case, MySQL does a single key lookup for eachMIN()orMAX()expre...
受影响的行:1150091时间:42.972sALTERTABLEsales_rankDROPINDEXwindex_countrycode;ALTERTABLEsales_rankDROPINDEXwindex_grab_amz_date;ALTERTABLEsales_rankDROPINDEXwindex_categoryid;ALTERTABLEsales_rankDROPINDEXwindex_grab_rank;[SQL]ALTERTABLEsales_rankDROPINDEXwindex_countrycode; 受影响的行:1150091时间:42.791...
I want to use the index on creation_date_time in the sub-query. However, explain plan shows that index on session_id is used (second line in the plan): +---+---+---+---+---+---+ | id | select_type | table | type | possible_keys | key | +---+---+---+---+--...
Well I’m no expert on the optimizer’s plans, but I suppose your key is just too long in order to be taken into account for the optimzer. Have you tried to force the use of an index? left JOIN cases_cstm ON cases.id = cases_cstm.id_c FORCE INDEX (id_c) ...
However, I can't run it in VS2017 because of this error: Severity Code Description Project File Line Suppression State Error An error occurred while signing: Failed to sign bin\Release\app.publish\SQLSvrDETool_OOP.exe. SignTool Error: No certificates were found that met all the given ...
Recently I was working with a customer wherein our focus was to carry out a performance audit of their multiple MySQL database nodes. We started looking into the stats of the performance schema. While working, the customer raised two interesting questions: how can he make complete use of the...
Index _WIN32_WINNT not defined. Defaulting to _WIN32_WINNT_MAXVER (see WinSDKVer.h) : A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed !> in c# . Check is object null - What are the options? .Ne...
PostgreSQL as a Service (PGaaS) is a specific form of Database as a Service (DBaaS) that enables users to easily create, manage, and use Postgres databases in the cloud. Various cloud service providers offer PGaaS options, including AWS with RDS for Postgres, Microsoft's Azur...
Is it possible to force mysql to use indexes for a small amount of data in the db? It is just for local development testing purposes. Can I change any parameter in mysql to force index usage? BACKGROUND I have created a java junit testing library that wraps all queries sent to the DB...