Delete all records take a long time

[ZihaoGuan]

Hi,

We want to clear the data when user logs out, and we notice that it would take a long time to perform record deletions for 5 different store in the same database.

Delete record count: 67916
Elapsed time: 44 s

Any suggestion to improve?

[alextekartik]

My guest is that you are using databaseFactoryIo which uses an append only file format. Deletion tends to trigger a compact operation which is extensive (rewriting the new file).

The first thing to try would be to do all the deletions in a single transaction so that only 1 compact operation happens.

But my recommendation would be to use the factory from sembast_sqflite since this compact operation does not happen so it should be much faster. The API is the same, it is only a matter of having a different factory to open the database.