顯示具有 Oracle 標籤的文章。 顯示所有文章
顯示具有 Oracle 標籤的文章。 顯示所有文章

2013年6月26日 星期三

oracle config (init.ora)

init.ora

share_pool_size

oracle tunning

cursor_sharing
1. avoid FTS (Full Table Scan)
2. cluster index-organized tables
3. cluster materialized view
4. Orace Patii
 Crsor sharing.

Oracle Database Tunning Harddisk (I O)


  • DBW (Database Base Writer) 
  • V$SYSTEM_EVENT , TOTAL_WAITS is high
  • the tuning goal for disk I/O performance is to balance I/O and reduce I/O contention. 
  • keep heavily used file separate from each other. 
  • keep non-Oracle files on disks separate from Oracle files. 
  • use Hardware Raid
  • do not place nonsystem object in the System Tablespace. 
  • use temporary tablespace for sort segments
  • keep table and index segments in separate tablespace
  • use locally managed tablespace to reduce system tablespace I/O and fragmentation
  • set the DB_FILE_MULTIBLOCK_READ_COUNT parameter to improve I/O where performing full table scans. (FTSs) 
  • Redo log file should be sized large enough so that redo log switchs do not happen so often that performance is affect.
  • Redo log files should be kept on separate fast devices. 
  • if the ARCn process cannot keep up the archiving requirement, you can specify additional ARCn processes by setting the LOG_ARCHIVE_MAX_PROCESSES parameter to a value between 1 and 10.