MySQL物理查詢最佳化技術---index dive辨析一 引子在MySQL的官方手冊上有這麼一句話:the optimizer can estimate the row count for each range using dives into the index or index statistics.這是在說: 最佳化器為每一個範圍段(如“a IN (10, 20, 30)”是等值比較,
SQL最佳化--邏輯最佳化--視圖重寫與等價謂詞重寫,sql謂詞1)視圖重寫視圖的類型:a)用SPJ格式構造的視圖,稱為簡單視圖。CREATE VIEW v1 AS SELECT x, y, z FROM t;b)用非SPJ格式構造的視圖(帶有GROUPBY等操作),稱為複雜視圖。CREATE VIEW v2 AS SELECT x, y, z FROM t ORDER BY
[HTTP:101216]Servlet: "FICMaster" failed to preload on startup in Web application,101216ficmaster最近弄了一次Oracle的OFSAA軟體,在部署程式時遇到個問題。目前網路上ofsaa的知識共用很少,在此分享給大家Symptoms錯誤資訊較多,現截取重要的錯誤部分,如下:<Jan 12, 2015 5:59:46 PM CST> <Warning> <
MHA+非root使用者SSH等效性配置,mha非rootssh環境:CentOS5.8 MySQL5.5.17實驗:搭建MHA高可用架構(非root使用者SSH等效性配置)SSH等效性使用者配置的是:concert 連接埠:1314MHA設定檔[concert@mhamanager mha]$ more
【翻譯自mos文章】當並行事務恢複進程在運行時,禁用並行事務恢複的方法,mos事務當並行事務恢複進程在運行時,禁用並行事務恢複的方法How to Disable Parallel Transaction Recovery When Parallel Txn Recovery is Active (Doc ID 238507.1)適用於:Oracle Database - Enterprise Edition - Version 8.1.5.0 to 11.2.0.4 [Release 8.1.5
【翻譯自mos文章】rman 備份時報:ORA-02396: exceeded maximum idle time,rmanora-02396rman 備份時報:ORA-02396: exceeded maximum idle time參考原文:RMAN backup faling with ORA-02396: exceeded maximum idle time, please connect again (Doc ID 1446182.1)適用於:Oracle Server -
1、錯誤描述java.sql.SQLException: ORA-0064:error occurred at recursive SQL level 1.ORA-06153:unable to extend table SYS.AUD$ by 8192 in tablespace SYSTEM.ORA-02002:error while writing to audit trail.ORA-00604:error occurred at recursive SQL level 1.ORA-01