# Explain Analyze

+ EXPLAIN ANALYZE executes the corresponding SQL statement, records information about its operation, and return it with the execution plan


![left](./student-guide/diagram/17-EXPLAIN-output-describing-01-01.png)

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Use EXPLAIN ANALYZE

The number of data items actually output by the ActRows operator.

The actual execution information of the execution info operator. Time represents the full wall time from entering the operator to leaving the operator, including the total execution time of all suboperator operations. If the operator is called multiple times (loops) by the parent operator, this time is the cumulative time. Loops is the number of times the current operator has been called by the parent operator.

The amount of memory space the memory operator takes up.

The amount of disk space the disk operator takes up.

Unlike EXPLAIN, EXPLAIN ANALYZE executes the corresponding SQL statement, records information about its execution, and return it with the execution plan. We can think of EXPLAIN ANALYZE as an scale of
EXPLAIN ANALYZE return more information than EXPLAIN:
  - The ActRows column represents the number of data actually output by the operator. When looking at the execution plan, if the ActRows and ESTrows columns differ significantly, in most cases, the statistics are problematic, and we can consider collecting the statistics again.
  - The ExecutionInfo column is the actual execution information of the operator. For example, wall time represents the total execution time of an operator. Loops represent the number of times the operator is called. Then wall time* loops can be understood as the cumulative time of the operator.
  - Memory represents the memory space occupied by the operator.
  - Disk represents the disk space occupied by the operator.