Frequent question: How do I archive a large table in MySQL?

How do I archive a table in MySQL?

What are the steps needed for this?

  1. Create the Archive Database and table.
  2. Insert into ArchiveDB. table select * from old_tbl where datetime <= Archivedate.
  3. Then DELETE FROM old_tbl WHERE datetime <= Archivedate.

How do I archive a large table in SQL Server?

Create a new table with all the columns being the same as in the original table with the additional identity column as the primary key. Load X days of data from the original table. Archive data from the original table to the [Archive] database by running a script in chunks of rows. Verify the result.

How do I limit the size of a table in MySQL?

You have to specify AVG_ROW_LENGTH only for tables with BLOB or TEXT columns; in this case, MySQL cannot optimize the space required based only on the number of rows. To change the default size limit for MyISAM tables, set the myisam_data_pointer_size , which sets the number of bytes used for internal row pointers.

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How do I find the largest table in MySQL?

To get largest table in MySQL database (of all databases) use: SELECT table_name AS “Table”, round(((data_length + index_length) / 1024 / 1024), 2) “Table size in MB” FROM information_schema. TABLES order by data_length+index_lenght desc limit 1; These queries may take time based on number of tables.

What is archive table in MySQL?

Archive is a storage engine for the MySQL relational database management system. Users can use this analytic storage engine to create a table that is “archive” only. Data cannot be deleted from this table, only added. … In MySQL 5.1, a copy of the MySQL FRM file is stored in the header of each Archive file.

How do I archive data in a table?


  1. Create a table with the same columns as the table for which you want to archive data. …
  2. Designate the original table as an archive-enabled table by issuing an ALTER TABLE statement with the ENABLE ARCHIVE clause. …
  3. If you want rows to be automatically archived, set the built-in global variable SYSIBMADM.

What is meant by data archiving?

Data archiving is the practice of identifying data that is no longer active and moving it out of production systems into long-term storage systems. Archival data is stored so that at any time it can be brought back into service.

How do I archive digital files?

Archiving Your Digital Materials

  1. Select. Identify the digital materials you want to keep over the long term. …
  2. Gather. Figure out where the files you want to keep are located and copy them to one central computer so they can be backed up. …
  3. Organize. Organize your files so they’ll be easy to browse or search. …
  4. Backup. …
  5. Maintain.
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What is archive table?

An archive table is a table that stores older rows from another table. The original table is called an archive-enabled table . Db2 can automatically store rows that are deleted from an archive-enabled table in an associated archive table.

Is Postgres faster than MySQL?

Ultimately, speed will depend on the way you’re using the database. PostgreSQL is known to be faster while handling massive data sets, complicated queries, and read-write operations. Meanwhile, MySQL is known to be faster with read-only commands.

What is the default file size limit for a table in MySQL?

MyISAM permits data and index files to grow up to 256TB by default, but this limit can be changed up to the maximum permissible size of 65,536TB (2567 − 1 bytes).

What is analyze table in MySQL?

ANALYZE TABLE performs a key distribution analysis and stores the distribution for the named table or tables. For MyISAM tables, this statement is equivalent to using myisamchk –analyze. This statement requires SELECT and INSERT privileges for the table. ANALYZE TABLE works with InnoDB , NDB , and MyISAM tables.

How do you determine the size of a table?

List Table Sizes From a Single Database

  1. SELECT TABLE_NAME AS `Table`, ROUND((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024) AS `Size (MB)` FROM information_schema. …
  2. SELECT TABLE_NAME AS `Table`, ROUND((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024) AS `Size (MB)` FROM information_schema.

How do I find the number of rows in a table in SQL?

The SQL COUNT() function returns the number of rows in a table satisfying the criteria specified in the WHERE clause. It sets the number of rows or non NULL column values. COUNT() returns 0 if there were no matching rows.

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