Oracle 视图 DBA_HIST_ROWCACHE_SUMMARY 官方解释，作用，如何使用详细说明
本站中文解释
Oracle视图DBA_HIST_ROWCACHE_SUMMARY可用于近期Oracle数据库统计，它可以查询数据字典查看块缓存在一段时间内的性能和使用情况。它提供了缓存访问的统计指标，如Physical Reads，Database Buffers，Row Cache Queries和Row Cache Hit Ratios等。使用此视图能够清楚地看到缓存的使用范围和效率，因此可以进一步优化缓存的性能以改善数据库的速度。
使用方法：通过SELECT *等SQL来访问此视图，可以查询指定时间内的统计数据，比如：
SELECT * FROM DBA_HIST_ROWCACHE_SUMMARY
WHERE snap_id BETWEEN&start_snap_id AND &end_snap_id;
此外，还可以使用AWR报表来查询缓存统计视图中的数据。
官方英文解释
DBA_HIST_ROWCACHE_SUMMARY displays historical summary statistics for data dictionary activity.
This view contains snapshots of V$ROWCACHE.
| Column | Datatype | NULL | Description |
|---|---|---|---|
|
|
| Unique snapshot ID |
|
|
| Database ID for the snapshot |
|
|
| Instance number for the snapshot |
|
|
| Name of the initialization parameter that determines the number of entries in the data dictionary cache |
|
| Sum of the total number of entries in the cache | |
|
| Number of cache entries that contain valid data | |
|
| Total number of requests for information on the data object | |
|
| Number of data requests resulting in cache misses | |
|
| Number of scan requests | |
|
| Number of times a scan failed to find the data in the cache | |
|
| For a list of subordinate entries, the number of times the list was scanned completely | |
|
| Number of inserts, updates, and deletions | |
|
| Number of times flushed to disk | |
|
| Number of DLM requests | |
|
| Number of DLM conflicts | |
|
| Number of DLM releases | |
|
| The database ID of the PDB for the sampled session | |
|
| The ID of the container that
|
See Also:
“V$ROWCACHE”
标签：缓存,视图,时间内,性能,数据库