Other Administrative Statements A key cache must exist before you assign indexes to it, or an error occurs: By default, table indexes are assigned to the main (default) key cache created at the server startup. When a key cache is destroyed, all indexes assigned to it are reassigned to the default key cache. Index assignment affects the server globally: If one client assigns an index to a given cache, this cache is used for all queries involving the index, no matter which client issues the queries. CACHE INDEX  is supported for partitioned  MyISAM  tables. You can assign one or more indexes for one, several, or all partitions to a given key cache. For example, you can do the following: mysql>  CACHE INDEX t1 IN non_existent_cache; ERROR 1284 (HY000): Unknown key cache ’non_existent_cache’ CREATE TABLE pt (c1 INT, c2 VARCHAR(50), INDEX i(c1)) ENGINE=MyISAM PARTITION BY HASH(c1) PARTITIONS 4; SET GLOBAL kc_fast.key_buffer_size = 128 * 1024; SET GLOBAL kc_slow.key_buffer_size = 128 * 1024; CACHE INDEX pt PARTITION (p0) IN kc_fast; CACHE INDEX pt PARTITION (p1, p3) IN kc_slow; The previous set of statements performs the following actions: •Creates a partitioned table with 4 partitions; these partitions are automatically named  p0 , ...,  p3 ; this table has an index named  i  on column  c1 . •Creates 2 key caches named  kc_fast  and  kc_slow •Assigns the index for partition  p0  to the  kc_fast  key cache and the index for partitions  p1  and  p3  to the kc_slow  key cache; the index for the remaining partition ( p2 ) uses the server’s default key cache. If you wish instead to assign the indexes for all partitions in table  pt  to a single key cache named  kc_all , you can use either of the following two statements: The two statements just shown are equivalent, and issuing either one has exactly the same effect. In other words, if you wish to assign indexes for all partitions of a partitioned table to the same key cache, the PARTITION (ALL)  clause is optional. When assigning indexes for multiple partitions to a key cache, the partitions need not be contiguous, and you need not list their names in any particular order. Indexes for any partitions not explicitly assigned to a key cache automatically use the server default key cache. Index preloading is also supported for partitioned  MyISAM  tables. For more information, see Section 13.7.8.5, “LOAD INDEX INTO CACHE Statement” . CACHE INDEX pt PARTITION (ALL) IN kc_all; CACHE INDEX pt IN kc_all; FLUSH [NO_WRITE_TO_BINLOG | LOCAL] { flush_option  [,  flush_option ] ... |  tables_option } flush_option : { BINARY LOGS 2970 13.7.8.3 FLUSH Statement