![]() The original content is preserved in the database file and new changes are added into the WAL file. The final commit saving the changes occurs when the rollback journal is deleted. New changes are written directly into the database file and the journal file is used to roll back changes in the case of a crash. Before WAL was introduced, SQLite was using the traditional rollback journal which works by keeping a copy of the original unchanged database content in the journal file. Journaling modes in Core Data and SQLite prevent data loss by writing new transactions in an in-between journal file. Write-Ahead Logging (WAL) results in multiple database files. In this blog post, I’ll give you both an example and an explanation of how you can do this. Because of this, you might want to force commit those changes into the SQLite store. ![]() This means that in some cases, changes are not yet visible in the SQLite store itself. ![]() With the WAL mode, Core Data keeps the main SQLite store file untouched and keeps track of data transactions in a -wal file within the same location of the SQLite store. The WAL mode is significantly faster in most scenarios compared to the previous default “rollback” journal mode and is the underlying reason that makes it possible to have concurrency in Core Data. Journaling in Core Data is best explained as the way data transactions are saved into the underlying SQLite store. Write-Ahead Logging is the default journaling mode for Core Data SQLite stores since iOS 7 and OS X Mavericks. 4 min read Write-Ahead Logging (WAL) disabled to force commits in Core Data.What to do when the delete journal mode is resulting in a dead lock.Verifying the configured journal mode using SQLite debugging.How to force commit changes into the SQLite database.Reasons to force commit changes into the SQLite store.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |