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. |
|
Specification | HiRDB processing mode and characteristics | Characteristics | |
---|---|---|---|
Response time | CPU usage | ||
pipe | Lock-release processing uses a pipe file to inform the process waiting for lock acquisition of lock release. Response time is not affected by the degree of job multiplexing. For this reason, the response time is constant compared to specifying interval or switch. | Long | Low |
interval | The process waiting for lock acquisition checks at regular intervals whether the lock is still in effect. Response time is affected by the degree of job multiplexing. For this reason, the greater the degree of job multiplexing, the longer the response time. | Short | High |
switch | The basic processing mode is the same as for interval. CPU usage is low compared to specifying interval because the CPU is used more efficiently. Tuning, however, is more difficult compared to when interval is specified. | Short | Medium |
pd_dbbuff_rate_updpage operand value | Number of update buffer sectors for deferred write trigger event |
---|---|
Specified | Number of global buffer sectors ![]() |
Omitted | Determined automatically by HiRDB |
Facility for acquiring global buffer control information traces | Level value |
---|---|
Facility for acquiring syncpoint output synchronization control information | 1 |