1.PreparedStatement and the statement contrast, if only the implementation of a single SQL statement, it goes without saying that is definitely Statement of efficiency, because it takes time before PreparedStatement pre-compiled, but will not produce ...
As a regular dealings with the database software developers, has not been resolved to seriously sum up the database. Although most came into contact with open source, mysql, then install the linux once oracle, and that was the end of 2005 when the or ...
Database administrator should understand that the redo log files of the mechanism and management mechanism similar to the data file. When the data is not updated, the new record or change the database structure, generate redo records, which are not i ...
---------- -------------- -------------------- 6323367 1252430 250,303 375,390 500,580 600,590 700,590 800,600 900,600 In this case: PGA distribution of at least 375M I personally think that PGA hit rate should not be less than 50% The following sql ...
Transfer from: http://tips.wbwb.net/measure-the-buffer-cache-hit-ratio/ Oracle database performance tuning, we need to observe the cache hit rate (Measure the Buffer Cache Hit Ratio ), You can use the following statement: - Get the initial cache hit ...
View data cache hit rate: SELECT ROUND ((1 - (phy.value / (cur.value + con.value))) * 100,2) "Cache Hit Ratio" FROM v $ sysstat cur, v $ sysstat con, v $ sysstat phy WHERE cur.name = 'db block gets' AND con.name = 'consistent ge ...
Data cache with multiple pools • By default, the data cache, there is only one (default) cache pool, there may be such a case, a user program to access a rarely used the occasional big table (non-full table scans), will be cached in the other users a ...
checkpoint literacy What is a checkpoint The role of checkpoint Checkpoint Categories related to the concept of checkpoint Terms RBA (Redo Byte Address), Low RBA (LRBA), High RBA (HRBA) Buffer checkpoint Queues (BCQ) Active checkpoint Queue (ACQ) Ful ...
500) this.width = 500; "height = 324> Data cache pool (Database Buffer) data files stored in data blocks of copy, to facilitate quick access to (minimize physical io). It contains the default buffer pool (Default pool), to preserve the cache ...
heapdump: dump PGA UGA SGA Immediately dump syntax: alter session set events 'immediate trace name heapdump level <level>'; With regard to the syntax error dump alter session set events '<error#> trace name heapdump level < ...
