Oracle SQL Execution Process (flowchart) _oracle

Oracle SQL execution Flowchart _sql execution process
First, the execution steps of the SQL statement:
1 grammar analysis, the analysis of the syntax of the sentence is consistent with the norms, measuring the meaning of the expressions in the statement.
2 semantic analysis, check the existence of all the database objects involved in the statement, and the user has the appropriate permissions.
3 View conversion to convert query statements involving views into corresponding base table query statements.
4 expression conversion to convert a complex SQL expression to a simpler equivalent join expression.
5 Select the optimizer, the different optimizer generally produces different "execution plan"
6 Select the connection mode, Oracle has three ways to connect, to multiple tables to connect Oracle to choose the appropriate way to connect.
7 Select the connection order, choose which pair of tables to connect to the multiple tables first, select which table in the two tables as the source data table.
8 Select the search path of the data, select the appropriate data search path according to the above conditions, choose the whole table search or use the index or other way.
9 Run "execution plan"
Flowchart (not a good draw)