By doing so, It can obviously fragment the database, and VACUUM Is anti fragmentation.
#Sqlite vacuum free
SQLite of Auto-VACUUM And VACUUM Not the same, It just moves free pages to the end of the database, This reduces the size of the database. You can also run on specific tables VACUUM, As shown below ： sqlite> VACUUM table_name
At the prompt VACUUM, As shown below ： sqlite> VACUUM The following is a command prompt for the entire database VACUUM Command syntax ： $sqlite3 database_name "VACUUM " because VACUUM Command to recreate the database file from scratch, So VACUUM It can also be used to modify many database specific configuration parameters. VACUUM Command is any operation for an in memory database. If there is an active transaction ,VACUUM The command will fail. In EF Core, the DbContext has a virtual method called. The next step is to create a custom DbContext class. Lets consider a simple model which contains three entities.
#Sqlite vacuum install
If there is no explicit integer primary key in the table （INTEGER PRIMARY KEY）,VACUUM The command may change the rows of entries in the table ID（ROWID）.VACUUM The command only applies to the primary database, Additional database files are not possible to use VACUUM Command. To use SQLite database provider, the first step is to install NuGet package. This eliminates free pages, Arrange the data in the table as continuous, In addition, the database file structure will be cleaned up. The fact that VACUUM cannot be executed within a transaction block means you cannot use such an approach, because a function is executed within a transaction block.VACUUM The command copies the contents of the primary database to a temporary database file, Then empty the primary database, And reload the original database file from the copy. In this particular case, one could think to define a function that executes VACUUM, then apply the SECURITY DEFINER option so that the function will run as the object owner, and then provide (i.e., GRANT) execution permission to a normal user. Why am I insisting on this? Because some friends of mine argued that it is always possible to escape restrictions with functions an SECURITY DEFINER options. Therefore there is no escape: in order to run VACUUM you must to be either (i) the object owner or (ii) the database owner or,as you can imagine, (iii) one of the cluster superuser(s). There is not an ACL flag about VACUUM, that means you cannot GRANT someone else to execute VACUUM. By default, the autovacuum feature is disabled. With this feature, you don't have to manually run the VACUUM statement. VACUUM cannot be executed inside a transaction block. Description Introduced in SQLite 3.1, autovacuum is an optional feature that automatically vacuums the database to minimize the size of the database file.
Embedded applications are encouraged to enable the error and warning log to help with debugging application problems that arise in the field. However, database owners are allowed to vacuum all tables in their databases, SQLite supports an 'error and warning log' design to capture information about suspicious and/or error events during operation. Optimize all FTS tables and then VACUUM sqlite-utils optimize mydb.db. To vacuum a table, one must ordinarily be the table's owner or a superuser. The sqlite-utils query command lets you run queries directly against a SQLite.
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