最佳化sql的利器SQLT

最佳化sql的利器SQLT

 

Sqlt適用環境：

1、 sql最佳化功底不是很深的同學

2、 sql太複雜（2000行以上的SQL）

3、 快速最佳化sql，不考慮業務邏輯

 

Setup SQLT Method：

SQL> conn /as sysdba

SQL> @/home/oracle/sqlt/install/sqcreate.sql

…

Define SQLTXPLAIN password (hidden and case sensitive).

Password for user SQLTXPLAIN:

Re-enter password:

…

Default tablespace [UNKNOWN]: USERS  <== hidden and case sensitive

…

Temporary tablespace [UNKNOWN]: TEMP  <== hidden and case sensitive

…

Main application user of SQLT: doudou    administrator;grant SQLT_USER_ROLE

…

Oracle Pack license [T]: T  <==choose

…

SQCREATE completed. Installation completed successfully.

 

Remove SQLT Method：

@/home/oracle/sqlt/install/sqdrop.sql

 

使用方法：

SQL> start sqltxtract.sql 0w6uydn50g8c <=SQL sql_id

 

附表：

Administrator privilege

grant connect,resource to doudou;

grant SQLT_USER_ROLE to doudou;

 

What is different SQLT XECUTE Method and SQLT XTRACT Method ?

 

SQLT XECUTE Method

? Pros

? Accurate 10053 (considers bind peeking)

? Plan execution statistics (sets STATISTICS_LEVEL=ALL)

? Actual Execution Plan (may be different than explain plan)

? Invokes SQL Tuning Advisor

? No need to know, or get before hand, hash_value or sql_id

? 10046 trace and Trace Analyzer (if installed)

? Cons

? SQL is executed (may take long time)

? Need to know the values of bind variables

 

Method

? Pros

? Child plans and plan statistics (if STATISTICS_LEVEL=ALL)

? Actual Execution Plan (may be different than explain plan)

? Invokes SQL Tuning Advisor

? SQL is not executed

? No need to know the values of bind variables

? Easy to execute (if hash_value or sql_id are known)

? Cons

? 10053 is generated based on EXPLAIN PLAN FOR (may not

be accurate due to binds peeking)

? Requires to know, or get before hand, hash_value or sql_id

 

 

總結：

最佳化SQL的又一利器SQLT（SQLTXPLAIN），SQLT把收集的資訊和建議方法都形成了html（main.html;readme.html;lite.html）格式，方便使用者檢視！

Main.html：SQLT給出了收集的資訊和調優建議

Readme.html：SQLT給出了具體最佳化的方法

Lite.html:SQLT給出了簡易的PLANS資訊 

 

參考文獻：Document 215187.1