| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently create an index for invalidation for accessing a cache of a database within a limited memory space. <P>SOLUTION: In order to maintain a cache hit rate for an index for invalidation within a limited size, a field for a count is provided in a table of indices for invalidation for each of hash-divided regions, the count is made increment in response to data update, and the count is made decrement in response to data reference. Rows of indices for invalidation are merged in response to the field for the count being larger than a predetermined threshold value, and a division of the rows of indices for invalidation is started in order from a row having a minimum count value as many as the number of rows which are made empty by merging. Therefore, the size of the index for invalidation is kept valid, and the cache hit rate is improved for reference access. <P>COPYRIGHT: (C)2012,JPO&INPIT |
