Used to specify the journal mode.
Class
TLiteConnectionOptions
Syntax
property JournalMode: TJournalMode default DefValJournalMode;
Remarks
Use the JournalMode property to specify the journal mode.
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jmDefault
- The default value. If the database was previously opened in the WAL mode, then Default will open the database in the WAL mode; otherwise, the database will be opened in the Delete mode.
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jmDelete
- The rollback journal is deleted at the conclusion of each transaction.
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jmMemory
- The rollback journal is stored in volatile RAM. This reduces the disk I/O, but decreases database safety and integrity. If the application using SQLite crashes in the middle of a transaction in this mode, the database file is likely to become corrupt.
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jmOff
- The rollback journal is completely disabled. No rollback journal is created, thus there is no rollback journal to delete. The ROLLBACK command does not work -- it behaves in an undefined way. Avoid using the ROLLBACK command when the journal mode is disabled.
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jmPersist
- The rollback journal file is not deleted when the transaction is commited. The header of the journal is filled with zeroes to prevent other connections rolling back from the journal. This mode optimizes performance on platforms where deleting or truncating a file is much more expensive than overwriting the first block of a file with zeros.
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jmTruncate
- The rollback journal is stored in volatile RAM. It reduces disk I/O, but decreases database safety and integrity. If the application using SQLite crashes in the middle of a transaction, the database file may become corrupt.
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jmWAL
- A write-ahead log is used instead of a rollback journal to implement transactions. When data database is updated, the original content is preserved in the database file and the changes are appended in a separate WAL file. All the transactions that are appended in the WAL file are eventually transferred back into the original database.
