wal

问题 I was reading this article about Tarantool and they seem to say that AOF and WAL log are not working the same way. Tarantool: besides snapshots, it has a full-scale WAL (write ahead log). So it can secure data persistency after each transaction out-of-the-box. Redis: in fact, it has snapshots only. Technically, you have AOF (append-only file, where all the operations are written), but it requires manual control over it, including manual restore after reboot. Simply put, with Redis you need to

问题 I was reading this article about Tarantool and they seem to say that AOF and WAL log are not working the same way. Tarantool: besides snapshots, it has a full-scale WAL (write ahead log). So it can secure data persistency after each transaction out-of-the-box. Redis: in fact, it has snapshots only. Technically, you have AOF (append-only file, where all the operations are written), but it requires manual control over it, including manual restore after reboot. Simply put, with Redis you need to

问题 I was reading this article about Tarantool and they seem to say that AOF and WAL log are not working the same way. Tarantool: besides snapshots, it has a full-scale WAL (write ahead log). So it can secure data persistency after each transaction out-of-the-box. Redis: in fact, it has snapshots only. Technically, you have AOF (append-only file, where all the operations are written), but it requires manual control over it, including manual restore after reboot. Simply put, with Redis you need to

问题 In Android Pie sqlite Write-Ahead logging (WAL) has been enabled by default. This is causing errors for my existing code only in Pie devices. I have been unable to turn off WAL successfully using SQLiteDatabase.disableWriteAheadLogging() or PRAGMA journal_mode due to the way I access the database. I would like to disable WAL completely with an Android setting called db_compatibility_wal_supported : Compatibility WAL (Write-Ahead Logging) for Apps Does anyone know how to configure this? I don

问题 In C#, how to open an SQLite connection in WAL mode? Here is how I open in normal mode: SQLiteConnection connection = new SQLiteConnection("Data Source=" + file); connection.Open(); // (Perform my query) 回答1: how about a factory approach to specify in the SQLiteConnection connetion string ? for e.g public static class Connection { public abstract SQLiteConnection NewConnection(String file); } public class NormalConnection : Connection { public override SQLiteConnection NewConnection(String

问题 In my application, I run a service at 12 each night using an Alarm, everything works as intended. I have three Fragment tabs, each tab has a listview, on click of a list item a detailed view is presented. If a user openes my app at say 11:59 (Before the service updates the underlying data from the database) he will get the data in the list view, but as the clock strikes 12, my processing starts and Database gets locked (I have implemented an exclusive lock on db while the service is running

问题 I plan to use Sqlite with WAL mode (on a web server). As I understand, the reads are never blocked with this mode, even when write occurs in the same time. There is still only one write transaction at a time but I guess the lock time is short because the actual write on the db occurs only when the WAL file exceed a certain size. So : How much time should I expect to be locked in WAL mode when the transaction is written on the WAL file ? When the WAL file is commited ? Is there any benchmarks

问题 How to achieve concurrency in SQLite database? As per documents it is possible using WAL(Write-Ahead Logging).But, I dont know how to implement it. In my app I want to read data from db on main thread and at the same time a background thread is writing/inserting some data in the same table. On executing read and write query at same time app stops responding until insertion isn't done. Is concurrency possible in SQLite, and how? 回答1: You need to use a singleton object of DataBase object. For

问题 With WAL (Write-Ahead-Logging) enabled in SQLite 3.7 (which is the default for Core Data on iOS 7), how do I merge/commit the content from the -wal file back into the main database file? 回答1: Do a checkpoint, i.e., execute PRAGMA wal_checkpoint. 回答2: From the command line, do this: sqlite3 MyDatabase.sqlite VACUUM; CTRL-D to exit the sqlite console. Done! The -wal file should now have a size of 0 and everything should be in your main database file. 来源： https://stackoverflow.com/questions

问题 I want to save the content of a MOC to a file myFile.ext . Everything works well, my data is saved to the file BUT I have to auxiliary files in addition: myFile.ext-wal myFile.ext-shm Are these files necessary for my purpose (saving the content of a MOC to a file)? I would like to "ship" my data in only one file. Furthermore, when I get again my data, I only use the URL of myFile.ext . If they are not necessary, is it possible to avoid their creation? 回答1: As CL indicated they are necessary