Oracle SQL Execution flowchart _ SQL Execution Process 1. SQL statement execution steps:
1) analyze the syntax and analyze whether the syntax of the statement complies with the specifications, to measure the meaning of each expression in the statement. 2) perform Semantic Analysis to check whether all database objects involved in the statement exist and the user has the corresponding permissions. 3) view conversion: converts query statements related to views into corresponding query statements for base tables. 4) expression conversion: converts complex SQL expressions into simple equivalent join expressions. 5) Select the optimizer. Different optimizer generally generate different "execution plans" www.2cto.com 6) Select the connection method, and ORACLE has three connection methods, select an appropriate connection mode for multi-Table ORACLE connection. 7) Select the connection sequence, select which table to connect to ORACLE for multi-Table connection, and select which table in the two tables as the source data table. 8) Select the data search path and select the appropriate data search path based on the preceding conditions. If you choose full table search or index or other methods. 9) run the "Execution Plan" Flow Chart (incorrect description)
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