commit existing journal file in sqlite from prior terminated connection to database

  • Last Update :
  • Techknowledgy :

I'd like to commit the existing journal to see if the current script is on the right track. Initially I just try (using the Python sqlite3 module on iPython):

connection = sqlite3.connect('mydatabase')

connection.commit()

Suggestion : 2

I'm prototyping a script that creates large SQLite databases with a four day time limit. The time limit was reached before the script finished and the connection.commit() command would be executed. The script is dropped and the database connection terminated but the journal is still in the file directory where the database was being created., 2 days ago Before reading from a database file, SQLite always checks to see if that database file has a hot journal. ... , respectively.) This is the instant when the changes are committed. Prior to deleting the journal file, if a power failure or crash occurs, the next process to open the database will see that it has a hot journal and will roll the ... , If empty, SQLite creates a temporary on-disk database that's deleted when the connection is closed. If :memory:, an in-memory database is used. For more information, see In-Memory databases. Paths that start with the |DataDirectory|substitution string are treated the same as relative paths. , If you specify an empty file name '', the statement creates a temporary file-backed database. Note that SQLite automatically deletes all temporary and memory databases when the database connection is closed. First, connect to the chinook sample database using sqlite3 command as follows:


connection = sqlite3.connect('mydatabase') connection.commit()
connection = sqlite3.connect('mydatabase') connection.commit()

Suggestion : 3

Each transient index is stored in its own temporary file. The temporary file for a transient index is automatically deleted at the end of the statement that uses it. , The temporary files associated with the TEMP database and its rollback journal are only created if the application makes use of the "CREATE TEMP TABLE" statement. , The temporary file created by the VACUUM command exists only for the duration of the command itself. The size of the temporary file will be no larger than the original database. , If a crash or power loss occurs in the middle of a transaction, then the rollback journal file is left on disk. The next time another application attempts to open the database file, it notices the presence of the abandoned rollback journal (we call it a "hot journal" in this circumstance) and uses the information in the journal to restore the database to its state prior to the start of the incomplete transaction. This is how SQLite implements atomic commit.

PRAGMA locking_mode = EXCLUSIVE;
UPDATE OR FAIL...
   UPDATE OR IGNORE...
   UPDATE OR REPLACE...
   UPDATE OR ROLLBACK...
   INSERT OR FAIL...
   INSERT OR IGNORE...
   INSERT OR REPLACE...
   INSERT OR ROLLBACK...
   REPLACE INTO....
SELECT * FROM ex1 WHERE ex1.a IN(SELECT b FROM ex2);
SELECT * FROM ex1 WHERE EXISTS(SELECT 1 FROM ex2 WHERE ex2.b = ex1.a);
SELECT * FROM ex1 WHERE a IN(1, 2, 3);
SELECT * FROM ex1 WHERE a IN(SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3);