MySQL Table and Column Name Completion Feature

When connecting to the database, a message appears:

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| backup_operation   |
| information_schema |
| operation          |
+--------------------+
3 rows in set (0.09 sec)

mysql> use operation;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

This message indicates that MySQL is reading table and column information for auto-completion. You can disable this feature by using the -A option during connection.

In simple terms, adding the -A parameter when logging into MySQL prevents it from pre-reading database information.

According to online sources, the issue occurs when the -A parameter is not used during the connection. The command should be:

mysql -hhostname -uusername -ppassword -Pport -A

Instead of:

mysql -hhostname -uusername -ppassword -Pport

When using 'use dbname', MySQL reads database information. With the -A option, this step is skipped.

The main factor causing this beahvior is when the database becomes large, leading to slower performence.

Another situation arises when accessing the database and seeing:

Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A<br></br>

This typically happens when the MySQL database is too large, causing the pre-reading process to take too long. If this problem has not occurred before, it may be due to an interrupted operation such as dropping a large table with millions of records.

To check the current processes:

mysql> show processlist ;

If a process with ID 16545618 is locking the table, you can terminate it using:

mysql> kill 16545618;

By removing these locked processes, MySQL will return to normal operation.

This information is sourced from:

https://www.linuxidc.com/Linux/2014-04/99419.htm

https://www.cnblogs.com/wajika/p/6773020.html

Tags: MySQL command-line Database Optimization table locking Performance Tuning

Posted on Sun, 16 Aug 2026 16:22:55 +0000 by PromaneX