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LOAD INDEX INTO CACHEtbl_index_list [,tbl_index_list] ...tbl_index_list:tbl_name    [PARTITION (partition_list)]    [{INDEX|KEY} (index_name[,index_name] ...)]    [IGNORE LEAVES]partition_list: {partition_name[,partition_name] ...  | ALL}

TheLOAD INDEX INTO CACHE statement preloads a table index into the key cache to which it has been assigned by an explicitCACHE INDEX statement, or into the default key cache otherwise.

LOAD INDEX INTO CACHE applies only toMyISAM tables, including partitionedMyISAM tables. In addition, indexes on partitioned tables can be preloaded for one, several, or all partitions.

TheIGNORE LEAVES modifier causes only blocks for the nonleaf nodes of the index to be preloaded.

IGNORE LEAVES is also supported for partitionedMyISAM tables.

The following statement preloads nodes (index blocks) of indexes for the tablest1 andt2:

mysql> LOAD INDEX INTO CACHE t1, t2 IGNORE LEAVES;+---------+--------------+----------+----------+| Table   | Op           | Msg_type | Msg_text |+---------+--------------+----------+----------+| test.t1 | preload_keys | status   | OK       || test.t2 | preload_keys | status   | OK       |+---------+--------------+----------+----------+

This statement preloads all index blocks fromt1. It preloads only blocks for the nonleaf nodes fromt2.

The syntax ofLOAD INDEX INTO CACHE enables you to specify that only particular indexes from a table should be preloaded. However, the implementation preloads all the table's indexes into the cache, so there is no reason to specify anything other than the table name.

It is possible to preload indexes on specific partitions of partitionedMyISAM tables. For example, of the following 2 statements, the first preloads indexes for partitionp0 of a partitioned tablept, while the second preloads the indexes for partitionsp1 andp3 of the same table:

LOAD INDEX INTO CACHE pt PARTITION (p0);LOAD INDEX INTO CACHE pt PARTITION (p1, p3);

To preload the indexes for all partitions in tablept, you can use either of the following two statements:

LOAD INDEX INTO CACHE pt PARTITION (ALL);LOAD INDEX INTO CACHE pt;

The two statements just shown are equivalent, and issuing either one has exactly the same effect. In other words, if you wish to preload indexes for all partitions of a partitioned table, thePARTITION (ALL) clause is optional.

When preloading indexes for multiple partitions, the partitions need not be contiguous, and you need not list their names in any particular order.

LOAD INDEX INTO CACHE ... IGNORE LEAVES fails unless all indexes in a table have the same block size. To determine index block sizes for a table, usemyisamchk -dv and check theBlocksize column.