The Ultimate Guide to High Availability with MariaDB

ANALYZE statement

You are viewing an old version of this article. View the current version here.
MariaDB starting with 10.0.0

The ANALYZE statement command is a new feature in MariaDB 10.1.0.

Contents

  1. Command description

Command description

ANALYZE statement command will run the statement, but instead of statement's output it will produce EXPLAIN output, accompanied with statistics from statement's execution.

MariaDB> analyze select * from tbl1 where key1 between 10 and 200 and col1 like 'foo%'\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: tbl1
         type: range
possible_keys: key1
          key: key1
      key_len: 5
          ref: NULL
         rows: 181
       r_rows: 181
     filtered: 100.00
   r_filtered: 10.50
        Extra: Using index condition; Using where
1 row in set (0.02 sec)
**gooo**

Compared to EXPLAIN, ANALYZE produces two extra columns:

  • r_rows is an observation-based counterpart of rows column. It shows how many rows were actually read from the table.
  • r_filtered is an observation-based counterpart of filtered column. It shows which fraction of rows was left after applying the WHERE condition.

Comments

Comments loading...
Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.