Item | Operand specification |
---|
Y | N |
---|
LRU management | When all global buffers are managed by the LRU method and there are insufficient global buffers, the least recently accessed global buffer in the global buffer pool is pushed from memory. | LRU management of global buffer is suppressed for branch row pages that store binary data and the least recently accessed page is cached. When global buffers are insufficient, the global buffer of the branch row page that stores the binary data is pushed from memory. |
Advantage | Global buffers are used evenly, regardless of the type of access data, so UAP performance is balanced. | Binary data is pushed first from the global buffer, even if accessed after large binary data, so search performance is maintained for non-binary data. |
Disadvantage | When accessing after large binary data, the most recently accessed data is pushed from the global buffer, so search performance declines for non-binary data. | - The buffer hit ratio declines in UAPs that access large binary data. That might increase the number of I/Os and decrease response performance.
- When binary data is updated, the system log volume increases with frequent pushing out of binary-data branch rows.
|