Oracle中Sql解析过程
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The SQL parsing process in Oracle typically involves the following procedure calls: 1. Open a cursor 2. Parse the SQL statement 3. Bind variables if needed and determine if the statement is a query 4. If a query, define columns. If not a query, execute the statement directly. 5. Fetch rows and return column values if it is a query.
Oracle中Sql解析过程
- 1. Oracle中SQL解析过程 -------------------------------------------------------------------------------- The flow of procedure calls will typically look like this: ----------- | open_cursor | ----------- | | v ----- ------------>| parse | | ----- | | | |--------- | v | | -------------- | |-------->| bind_variable | | | ^ ------------- | | | | | | -----------| | | |<-------- | v | query?---------- yes --------- | | | | no | | | | | v v | ------- ------------- |----------->| execute | ->| define_column | | ------- | ------------- | |------------ | | | | | ----------| | v | v | -------------- | ------- | ->| variable_value | | ------>| execute | | | -------------- | | ------- | | | | | | | ----------| | | | | | | | v | | | | ---------- | |<----------- |----->| fetch_rows | | | | ---------- | | | | | | | v | | | -------------------- | | | | column_value | | | | | variable_value | | | | --------------------- | | | | | |<-------------------------- | | -----------------| | v ------------ | close_cursor | ------------ -------------------------------------------------------------------------------- set pagesize 100; SELECT substr(t.text, 5, 1000) FROM all_source t WHERE t.owner = 'SYS' AND t.type = 'PACKAGE' AND t.name = 'DBMS_SQL' AND t.line <= 95 AND t.line >= 38;