# SQLite3 HTTP VFS Driver

You are currently using the shared cache backend (cross-origin isolated environment)
You are currently using the sync backend (legacy environment, check this guide)
SQLite DB URL
SQL
Don't even think about trying an unconstrained `COUNT(*)`, with 16M records it takes 20 seconds when using local disk I/O
Things that work well:
`SELECT zoom_level, tile_row, tile_column FROM tiles WHERE zoom_level = 1`
`SELECT tile_data FROM tiles WHERE zoom_level = 10 AND tile_row = 600 AND tile_column = 600`
`SELECT COUNT(*) FROM tiles WHERE zoom_level < 10`

##### SQLite Worker Message

##### SQL Data