Always recreate views when starting the pool worker.

This makes it possible to change the definitions of views as required.

lib/core/src/Cardano/Pool/DB/Sqlite.hs

@@ -608,11 +608,18 @@ data DatabaseView = DatabaseView
 --
 createView :: Sqlite.Connection -> DatabaseView -> IO ()
 createView conn (DatabaseView name definition) = do
- query <- Sqlite.prepare conn queryString
- Sqlite.step query *> Sqlite.finalize query
+ deleteQuery <- Sqlite.prepare conn deleteQueryString
+ Sqlite.step deleteQuery *> Sqlite.finalize deleteQuery
+ createQuery <- Sqlite.prepare conn createQueryString
+ Sqlite.step createQuery *> Sqlite.finalize createQuery
  where
- queryString = T.unlines
- [ "CREATE VIEW IF NOT EXISTS"
+ deleteQueryString = T.unlines
+ [ "DROP VIEW IF EXISTS"
+ , name
+ , ";"
+ ]
+ createQueryString = T.unlines
+ [ "CREATE VIEW"
  , name
  , "AS"
  , definition