I have seen different kinds of ‘analyze’: a. analyze table xxxx estimate statistics sample 10 percent; b. analyze table xxxx estimate statistics sample 10 percent for table for all indexes for all indexed columns; c. ANALYZE table scott estimate statistics sample 1000 rows; analyze index sc_idx compute statistics; analyze index sc_idx validate structure; Related Posts: – Oracle: DBMS_UTILITY. Hi, What will. Code: Select all Show/ hide. analyze table tablename compute statistics. do.? and when should we use this command?
Hi there, I’ve Analyze statement below which was working fine when we have Oracle 9i. COMPUTE STATISTICS, not ANALYZE TABLE. Table statistics can be gathered for the database, schema, table or partition. ANALYZE TABLE employees ESTIMATE STATISTICS SAMPLE 100 ROWS; Note: Do not use the COMPUTE and ESTIMATE clauses of ANALYZE to collect optimizer statistics. These clauses are supported for backward compatibility.
We have two options available within the analyze table command, the computes statistics option and the estimate statistics command syntax. When we issue a computes statistics command, the entire table is examined via a full-table scan, and very accurate statistics are then placed inside the data dictionary for use by the cost-based optimizer. The second mode of the ANALYZE command estimates statistics. This method performs a sampling of the table, cluster, or index in order to estimate statistics. Both computed and estimated statistics are used by the Oracle optimizer to choose the execution plan for SQL statements that access analyzed objects. Estimate statistics Both computed and estimated statistics are used by the Oracle optimizer to choose the execution plan for SQL statements that access analyzed objects. For estimations, Oracle requires enough space to perform a scan and sort of only the rows in the requested sample of the table.
Analyze Table Command In 10g
When a table is analyzed, you can see that the NUM_ROWS and AVG_ROW_LEN columns of the Remote DBA_TABLE view are now populated with information. ANALYZE TABLE xxx ESTIMATE STATISTICS SAMPLE nn ROWS;