Oracle Enterprise Manager for MySQL Database

7.20 Myisam Configuration Metrics

Lists the Myisam configuration metrics and provides a brief description of each.

Table 7.20 Myisam Configuration Metrics

NameDescription
Concurrent InsertPermits INSERT and SELECT statements to run concurrently for MyISAM tables that have no free blocks in the middle of the data file.
Delay Key WriteDelayed key writing causes key buffers not to be flushed between writes for MyISAM tables.
Keep Files On Create EnabledWhether to overwrite MyISAM MYD/MYI files or return an error if no DATA DIRECTORY / INDEX DIRECTORY option is set, and the files already exist.
Key Buffer SizeThe size of the buffer used for MyISAM index blocks.
Key Cache Age ThresholdControls the demotion of buffers from the hot sublist of a MyISAM key cache to the warm sublist.
Key Cache Block SizeThe size in bytes of blocks in the MyISAM key cache.
Key Cache Division LimitThe division point between the hot and warm sublists of the MyISAM key cache buffer list.
Myisam Data Pointer SizeThe default pointer size, in bytes, to be used by CREATE TABLE for MyISAM tables when no MAX_ROWS option is specified.
Myisam Max Sort File SizeThe maximum size of the temporary file that MySQL is permitted to use while re-creating a MyISAM index (during REPAIR TABLE, ALTER TABLE, or LOAD DATA INFILE).
Myisam Mmap SizeThe maximum amount of memory to use for memory mapping compressed MyISAM files.
Myisam Recover OptionsSets the MyISAM storage engine recovery mode.
Myisam Repair ThreadsIf this value is greater than 1, MyISAM table indexes are created in parallel (each index in its own thread) during the Repair by sorting process.
Myisam Sort Buffer SizeThe size of the buffer that is allocated when sorting MyISAM indexes during a REPAIR TABLE or when creating indexes with CREATE INDEX or ALTER TABLE.
Myisam Stats MethodHow the server treats NULL values when collecting statistics about the distribution of index values for MyISAM tables.
Myisam Use Mmap EnabledUse memory mapping for reading and writing MyISAM tables.
Skip External Locking EnabledDo not use external locking (system locking) to lock MyISAMtable files.