AWR里有個execute to parse的指標,數字越大說明直接執行不經過決議的sql比例越大。
但是參考oracle檔案敘述如下:
SQL Parsing
The first stage of SQL processing is parsing.
The parsing stage involves separating the pieces of a SQL statement into a data structure that other routines can process. The database parses a statement when instructed by the application, which means that only the application-, and not the database itself, can reduce the number of parses.
When an application issues a SQL statement, the application makes a parse call to the database to prepare the statement for execution.
2個要點:
1、資料庫聽從程式要不要決議的指令,只有程式自己才能減少決議
2、每當程式發出一條SQL,程式會發出一個parse call
這兩點看起來就有點矛盾,每當程式發出一套sql都會發出parse call的話,那不就是已經是進入決議流程?
那程式又怎么才能讓資料庫不做決議呢?
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