Hence, Auto-VACUUM just keeps the database small. By doing so it can significantly fragment the database while VACUUM ensures defragmentation. SQLite Auto-VACUUM does not do the same as VACUUM rather it only moves free pages to the end of the database thereby reducing the database size. SQLite is an in-process library that implements a self-contained, serverless, transactional SQL database engine. You can also run VACUUM on a particular table as follows − Tuesday, 12 February 2019 The team at SQLite has added a Vacuum Into command that lets you back up a database atomically so that the backup is as small as possible and contains no forensic traces of deleted content. You can run VACUUM from SQLite prompt as well as follows − Manual VACUUMįollowing is a simple syntax to issue a VACUUM command for the whole database from command prompt − Specifying FREEZE is equivalent to performing VACUUM with the vacuumfreezeminage parameter set to zero. As the VACUUM command rebuilds the database file from scratch, VACUUM can also be used to modify many database-specific configuration parameters. Selects 'full' vacuum, which can reclaim more space, but takes much longer and exclusively locks the table. VACUUM command is a no-op for in-memory databases. VACUUM command will fail if there is an active transaction. It is not possible to VACUUM an attached database file. The VACUUM command only works on the main database. VACUUM command may change the ROWID of entries in tables that do not have an explicit INTEGER PRIMARY KEY. This eliminates free pages, aligns table data to be contiguous, and otherwise cleans up the database file structure. sqlite3 Test.db < insertdata. Using ( cmd = conn.VACUUM command cleans the main database by copying its contents to a temporary database file and reloading the original database file from the copy. If you’re on Windows, you might need to do this: sqlite3.exe Test.db '.read insertdata.sql' Redirect the Input to the Database when Connecting to SQLite The following method redirects the input to the database file when using sqlite3 to connect to SQLite and open the database. Public static void CompactDatabase(this SQLiteConnection conn) / An open SQLite connection that has no pending transactions open or queries running. If an open transaction exists or there are open / Compacts (vacuum) or shrinks a SQLite database via the open SQLiteConnection. The VACUUM statement helps clean the primary dataset by transferring its records to a transient data file and then rebuilding the entire database again from. Public Sub CompactDatabase(conn As SQLiteConnection) ''' An open SQLite connection that has no pending transactions open or queries running. ''' Compacts (vacuum) or shrinks a SQLite database via the open SQLiteConnection. Usage just requires that the connection is opened when "CompactDatabase" is called. I have a simple extension method off of SQLiteConnection that I use when I want to shrink the database from code. After a vacuum the tables/indexes will largely be stored contiguously. This can help fragmented databases where a table or indexes maybe stored in different sections of the file (the database can become fragmented over time with many inserts/updates/deletes). ![]() It does this by copying the contents of the db into a temporary database, rebuilding the main database and then copying the data back in. ![]() The vacuum command in SQLite provides a way to effectively shrink the database.
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