How to reclaim disk space after deleting data from table?

How to reclaim disk space after deleting data from table?

There are several ways to reclaim diskspace after deleting data from table for MySQL Inodb engine If you don’t use innodb_file_per_table from the beginning, dumping all data, delete all file, recreate database and import data again is only way ( check answers of FlipMcF above )

Why does InnoDB not release disk space after deleting data?

Ever. Even if you use optimize table to free the space used from deleted records, it will reuse it later. An alternative is to configure the server to use innodb_file_per_table, but this will require a backup, drop database and restore. The positive side is that the .ibd file for the table is reduced after an optimize table.

Why does MySQL not release disk space after deleting data?

What happens is, that even if you drop the database, innodb will still not release disk space. I had to export, stop mysql, remove the files manually, start mysql, create database and users, and then import. Thank god I only had 200MB worth of rows, but it spared 250GB of innodb file. Fail by design.

How to reduce table size in MySQL InnoDB?

Be sure to also retain a copy of your schema in your dump. Currently, you cannot remove a data file from the system tablespace. To decrease the system tablespace size, use this procedure: Use mysqldump to dump all your InnoDB tables. Stop the server. Remove all the existing tablespace files, including the ibdata and ib_log files.

How can I reduce the size of my SQL Server?

If you are the lucky enough to have Enterprise Edition of SQL Server, you can reduce the size of the data by implementing Data Compression. There are two types of Data Compression supported in SQL Server – Row and Page. Row compression addresses the storage inefficiency introduced by fixed-length data types.

What happens when you add a new column in a table?

Here were my thoughts on the first suggestion, adding a new column. This should work because adding the new column is a schema change only so it will be almost instant and take no extra space. Once I start putting data into the column it will actually add space to the row, potentially causing page splits.

Why is it important to reduce the size of a database?

Even though size reduction is rarely the primary objectives of such projects, reducing the size often helps to achieve other goals. Think about designing Disaster Recovery (DR) strategy. Plenty of things that can help to meet strict RTO requirements and smaller database size definitely helps.

How to reduce the size of ibdata1 in MySQL?

MySQL doesn’t reduce the size of ibdata1. Ever. Even if you use optimize table to free the space used from deleted records, it will reuse it later. An alternative is to configure the server to use innodb_file_per_table, but this will require a backup, drop database and restore.

How many GB is in my DB Export dump?

Actually I am bit confused with my database export, while i exporting it shows “Total estimation using BLOCKS method: 20.83 GB” But my DB export dump is only 6 GB. Few days back we deleted some unwanted files and data from our database.

What happens if the table size is fragmented?

If the tables are fragmented then actual size may vary. In your case, as you have said, you had heavy deletion in the past which didn’t shrink down the High Water Mark leading data pump to count empty blocks as well during the estimation.