The Ultimate Guide to High Availability with MariaDB
This is a read-only copy of the MariaDB Knowledgebase generated on 2024-11-14. For the latest, interactive version please visit https://mariadb.com/kb/.

Information Schema QUERY_CACHE_INFO Table

Description

The table is not a standard Information Schema table, and is a MariaDB extension.

The QUERY_CACHE_INFO table is created by the QUERY_CACHE_INFO plugin, and allows you to see the contents of the query cache. It creates a table in the information_schema database that shows all queries that are in the cache. You must have the PROCESS privilege (see GRANT) to use this table.

It contains the following columns:

ColumnDescription
STATEMENT_SCHEMADatabase used when query was included
STATEMENT_TEXTQuery text
RESULT_BLOCKS_COUNTNumber of result blocks
RESULT_BLOCKS_SIZESize in bytes of result blocks
RESULT_BLOCKS_SIZE_USEDSize in bytes of used blocks
LIMITAdded MariaDB 10.1.8.
MAX_SORT_LENGTHAdded MariaDB 10.1.8.
GROUP_CONCAT_MAX_LENGTHAdded MariaDB 10.1.8.
CHARACTER_SET_CLIENTAdded MariaDB 10.1.8.
CHARACTER_SET_RESULTAdded MariaDB 10.1.8.
COLLATION Added MariaDB 10.1.8.
TIMEZONEAdded MariaDB 10.1.8.
DEFAULT_WEEK_FORMATAdded MariaDB 10.1.8.
DIV_PRECISION_INCREMENTAdded MariaDB 10.1.8.
SQL_MODEAdded MariaDB 10.1.8.
LC_TIME_NAMESAdded MariaDB 10.1.8.
CLIENT_LONG_FLAGAdded MariaDB 10.1.8.
CLIENT_PROTOCOL_41Added MariaDB 10.1.8.
PROTOCOL_TYPEAdded MariaDB 10.1.8.
MORE_RESULTS_EXISTSAdded MariaDB 10.1.8.
IN_TRANSAdded MariaDB 10.1.8.
AUTOCOMMITAdded MariaDB 10.1.8.
PACKET_NUMBERAdded MariaDB 10.1.8.
HITSIncremented each time the query cache is hit. Added MariaDB 10.3.2.

For example:

SELECT * FROM information_schema.QUERY_CACHE_INFO;
+------------------+-----------------+---------------------+--------------------+-------------------------+
| STATEMENT_SCHEMA | STATEMENT_TEXT  | RESULT_BLOCKS_COUNT | RESULT_BLOCKS_SIZE | RESULT_BLOCKS_SIZE_USED |
+------------------+-----------------+---------------------+--------------------+-------------------------+
...
| test             | SELECT * FROM a |                   1 |                512 |                     143 |
| test             | select * FROM a |                   1 |                512 |                     143 |
...
+------------------+-----------------+---------------------+--------------------+-------------------------
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