SQLite: efficient way to drop lots of rows

Question

SQlite, Android, true story. I have a table, which I use as a cache:

CREATE TABLE cache(key TEXT, ts TIMESTAMP, size INTEGER, data BLOB);
CREATE UNIQUE INDEX         


        

Answer 1

You have two options to improve the performance, especially the first one:

1) Using Transaction like this:

DbTransaction trans = conn.BeginTransaction(); // <-------------------
try 
{
   Any code to delete the items
}
catch
{
    trans.Rollback(); // <-------------------
    throw; // <-------------------
}

2) Otherwise, supposing that the items are continuous, then

• a) Get the ID of the first item;

• b) Get the total number of items to be deleted

• c) Using command like this:

  DELETE FROM blobs WHERE ID > fistId LIMIT count;

Good luck.