I am using MySQL in localhost as a "query tool" for performing statistics in R, that is, everytime I run a R script, I create a new database (A), create a new table (B), import the data into B, submit a query to get what I need, and then I drop B and drop A.
It's working fine for me, but I realize that the ibdata file size is increasing rapidly, I stored nothing in MySQL, but the ibdata1 file already exceeded 100 MB.
I am using more or less default MySQL setting for the setup, is there a way for I can automatically shrink/purge the ibdata1 file after a fixed period of time?
That ibdata1
isn't shrinking is a particularly annoying feature of MySQL. The ibdata1
file can't actually be shrunk unless you delete all databases, remove the files and reload a dump.
But you can configure MySQL so that each table, including its indexes, is stored as a separate file. In that way ibdata1
will not grow as large. According to Bill Karwin's comment this is enabled by default as of version 5.6.6 of MySQL.
It was a while ago I did this. However, to setup your server to use separate files for each table you need to change my.cnf
in order to enable this:
[mysqld]
innodb_file_per_table=1
https://dev.mysql.com/doc/refman/5.6/en/innodb-file-per-table-tablespaces.html
As you want to reclaim the space from ibdata1
you actually have to delete the file:
mysqldump
of all databases, procedures, triggers etc except the mysql
and performance_schema
databasesibdata1
and ib_log
filesWhen you start MySQL in step 5 the ibdata1
and ib_log
files will be recreated.
Now you're fit to go. When you create a new database for analysis, the tables will be located in separate ibd*
files, not in ibdata1
. As you usually drop the database soon after, the ibd*
files will be deleted.
http://dev.mysql.com/doc/refman/5.1/en/drop-database.html
You have probably seen this:
http://bugs.mysql.com/bug.php?id=1341
By using the command ALTER TABLE <tablename> ENGINE=innodb
or OPTIMIZE TABLE <tablename>
one can extract data and index pages from ibdata1 to separate files. However, ibdata1 will not shrink unless you do the steps above.
Regarding the information_schema
, that is not necessary nor possible to drop. It is in fact just a bunch of read-only views, not tables. And there are no files associated with the them, not even a database directory. The informations_schema
is using the memory db-engine and is dropped and regenerated upon stop/restart of mysqld. See https://dev.mysql.com/doc/refman/5.7/en/information-schema.html.