MySQL 8.0 No Longer Updates Information_schema.tables After Optimizing A Table

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Introduction

MySQL 8.0 has introduced several improvements and enhancements to its database management system. However, with the latest version, some users have encountered an issue where the information_schema.tables table is no longer updated after optimizing a table. This problem can be particularly challenging for database administrators who rely on this schema to monitor and manage their databases.

Background Information

We have recently been undertaking a purge of data from our databases, which has left some tables with huge amounts of free space (in some cases hundreds of GBs). So, I have started a process of going through these tables and optimizing them to reclaim the unused space. However, after optimizing a table, I noticed that the information_schema.tables table was not being updated accordingly.

Understanding the Issue

The information_schema.tables table is a system view in MySQL that provides information about the tables in a database. It contains columns such as TABLE_NAME, TABLE_TYPE, ENGINE, VERSION, and ROW_FORMAT, among others. This table is essential for database administrators to monitor and manage their databases.

However, after optimizing a table in MySQL 8.0, the information_schema.tables table is not being updated. This means that the information about the table's size, engine, and other attributes is not being reflected in the information_schema.tables table.

Possible Causes

There are several possible causes for this issue:

  • Optimization Method: The method used to optimize the table might be causing the issue. For example, if the table is being optimized using the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option, it might not update the information_schema.tables table.
  • Table Engine: The table engine being used might be causing the issue. For example, if the table is using the InnoDB engine, it might not update the information_schema.tables table after optimization.
  • MySQL Version: The MySQL version being used might be causing the issue. MySQL 8.0 has introduced several changes to the database management system, and some of these changes might be causing the issue.

Workarounds

There are several workarounds to this issue:

  • Use the information_schema.tables table with caution: Since the information_schema.tables table is not being updated after optimization, it's essential to use it with caution. You should verify the information in this table by checking the actual table size and attributes.
  • Use the SHOW TABLE STATUS statement: You can use the SHOW TABLE STATUS statement to get information about the table's size, engine, and other attributes. This statement will provide you with the actual information about the table, which can be used to verify the information in the information_schema.tables table.
  • Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option: You can use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option to optimize the table without updating the information_schema.tables table.

Conclusion

In conclusion, the issue with the information_schema.tables table not being updated after optimizing a table in MySQL 8.0 is a complex problem that requires careful analysis and troubleshooting. By understanding the possible causes and workarounds, you can resolve this issue and ensure that your database is running smoothly.

Recommendations

To avoid this issue in the future, we recommend the following:

  • Use the SHOW TABLE STATUS statement: Use the SHOW TABLE STATUS statement to get information about the table's size, engine, and other attributes.
  • Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option: Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option to optimize the table without updating the information_schema.tables table.
  • Verify the information in the information_schema.tables table: Verify the information in the information_schema.tables table by checking the actual table size and attributes.

Future Development

MySQL is constantly evolving, and new features and enhancements are being introduced with each new version. It's essential to stay up-to-date with the latest developments and best practices to ensure that your database is running smoothly.

Additional Resources

For more information about this issue and its workarounds, you can refer to the following resources:

  • MySQL Documentation: The official MySQL documentation provides detailed information about the information_schema.tables table and its usage.
  • MySQL Forums: The MySQL forums are a great resource for discussing issues and getting help from other users and experts.
  • MySQL Blog: The MySQL blog provides updates and news about the latest developments and enhancements in the MySQL database management system.

Conclusion

Q: What is the issue with the information_schema.tables table in MySQL 8.0?

A: The information_schema.tables table is not being updated after optimizing a table in MySQL 8.0. This means that the information about the table's size, engine, and other attributes is not being reflected in the information_schema.tables table.

Q: What are the possible causes of this issue?

A: There are several possible causes for this issue, including:

  • Optimization Method: The method used to optimize the table might be causing the issue. For example, if the table is being optimized using the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option, it might not update the information_schema.tables table.
  • Table Engine: The table engine being used might be causing the issue. For example, if the table is using the InnoDB engine, it might not update the information_schema.tables table after optimization.
  • MySQL Version: The MySQL version being used might be causing the issue. MySQL 8.0 has introduced several changes to the database management system, and some of these changes might be causing the issue.

Q: How can I resolve this issue?

A: There are several workarounds to this issue, including:

  • Use the SHOW TABLE STATUS statement: You can use the SHOW TABLE STATUS statement to get information about the table's size, engine, and other attributes. This statement will provide you with the actual information about the table, which can be used to verify the information in the information_schema.tables table.
  • Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option: You can use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option to optimize the table without updating the information_schema.tables table.
  • Verify the information in the information_schema.tables table: Verify the information in the information_schema.tables table by checking the actual table size and attributes.

Q: What are the best practices for avoiding this issue in the future?

A: To avoid this issue in the future, we recommend the following:

  • Use the SHOW TABLE STATUS statement: Use the SHOW TABLE STATUS statement to get information about the table's size, engine, and other attributes.
  • Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option: Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option to optimize the table without updating the information_schema.tables table.
  • Verify the information in the information_schema.tables table: Verify the information in the information_schema.tables table by checking the actual table size and attributes.

Q: What are the implications of this issue on database performance?

A: The issue with the information_schema.tables table not being updated after optimizing a table in MySQL 8.0 can have implications on database performance. For example, if the information_schema.tables table is not being updated, it can lead to incorrect information about the table's size and attributes, which can affect database performance.

Q: How can I stay up-to-date with the latest developments and best practices for MySQL 8.0?

A: To stay up-to-date with the latest developments and best practices for MySQL 8.0, we recommend the following:

  • MySQL Documentation: The official MySQL documentation provides detailed information about the information_schema.tables table and its usage.
  • MySQL Forums: The MySQL forums are a great resource for discussing issues and getting help from other users and experts.
  • MySQL Blog: The MySQL blog provides updates and news about the latest developments and enhancements in the MySQL database management system.

Q: What are the next steps for resolving this issue?

A: The next steps for resolving this issue are to:

  • Verify the information in the information_schema.tables table: Verify the information in the information_schema.tables table by checking the actual table size and attributes.
  • Use the SHOW TABLE STATUS statement: Use the SHOW TABLE STATUS statement to get information about the table's size, engine, and other attributes.
  • Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option: Use the OPTIMIZE TABLE statement with the ALGORITHM=INPLACE option to optimize the table without updating the information_schema.tables table.

By following these steps, you can resolve the issue with the information_schema.tables table not being updated after optimizing a table in MySQL 8.0 and ensure that your database is running smoothly.