Error #1273: Unknown Collation 'utf8mb4_0900_ai_ci' in MariaDB
Error Description
When working with MariaDB, you may encounter an error message indicating that the collation 'utf8mb4_0900_ai_ci' is unknown. This error occurs when the database system is unable to recognize the specified collation, which is a crucial aspect of character set management.
What is a Collation?
In database management systems like MariaDB, a collation is a set of rules that defines how strings are compared and sorted. It is an essential aspect of character set management, as it determines the order in which characters are arranged. Collations are used to ensure that data is stored and retrieved correctly, especially when dealing with non-English languages or special characters.
What is utf8mb4_0900_ai_ci?
The collation 'utf8mb4_0900_ai_ci' is a modern collation introduced in MySQL 8.0 and MariaDB 10.2. It is an extension of the UTF-8 character set, which provides support for a wider range of languages and emojis. The '0900' in the collation name indicates that it is a Unicode 9.0-based collation, which offers improved support for emojis and other non-BMP characters.
Causes of the Error
There are several reasons why you may encounter the 'unknown collation' error:
- Outdated MariaDB version: If you are running an older version of MariaDB, it may not support the 'utf8mb4_0900_ai_ci' collation. You may need to upgrade to a newer version of MariaDB that supports this collation.
- Incorrect character set configuration: The character set configuration in your MariaDB installation may be incorrectly set, leading to the error. Check your character set settings to ensure that they are correct.
- Corrupted database or tables: Corrupted database or tables can also cause the error. Try running a CHECK TABLE and REPAIR TABLE statement to fix any errors.
Solutions
To resolve the 'unknown collation' error, follow these steps:
1. Upgrade MariaDB
If you are running an older version of MariaDB, upgrade to a newer version that supports the 'utf8mb4_0900_ai_ci' collation.
2. Check Character Set Configuration
Verify that your character set configuration is correct. Use the following command to check:
SHOW VARIABLES LIKE 'character_set%';
3. Fix Corrupted Database or Tables
Run the following commands to check and repair any corrupted database or tables:
CHECK TABLE table_name;
REPAIR TABLE table_name;
By following these steps, you should be able to resolve the 'unknown collation' error and get your MariaDB installation up and running smoothly.
