configure_connection

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 714
        def configure_connection
          if @config[:timeout] && @config[:retries]
            raise ArgumentError, "Cannot specify both timeout and retries arguments"
          elsif @config[:timeout]
            @raw_connection.busy_timeout(self.class.type_cast_config_to_integer(@config[:timeout]))
          elsif @config[:retries]
            retries = self.class.type_cast_config_to_integer(@config[:retries])
            raw_connection.busy_handler do |count|
              count <= retries
            end
          end

          # Enforce foreign key constraints
          # https://www.sqlite.org/pragma.html#pragma_foreign_keys
          # https://www.sqlite.org/foreignkeys.html
          raw_execute("PRAGMA foreign_keys = ON", "SCHEMA")
          unless @memory_database
            # Journal mode WAL allows for greater concurrency (many readers + one writer)
            # https://www.sqlite.org/pragma.html#pragma_journal_mode
            raw_execute("PRAGMA journal_mode = WAL", "SCHEMA")
            # Set more relaxed level of database durability
            # 2 = "FULL" (sync on every write), 1 = "NORMAL" (sync every 1000 written pages) and 0 = "NONE"
            # https://www.sqlite.org/pragma.html#pragma_synchronous
            raw_execute("PRAGMA synchronous = NORMAL", "SCHEMA")
            # Set the global memory map so all processes can share some data
            # https://www.sqlite.org/pragma.html#pragma_mmap_size
            # https://www.sqlite.org/mmap.html
            raw_execute("PRAGMA mmap_size = #{128.megabytes}", "SCHEMA")
          end
          # Impose a limit on the WAL file to prevent unlimited growth
          # https://www.sqlite.org/pragma.html#pragma_journal_size_limit
          raw_execute("PRAGMA journal_size_limit = #{64.megabytes}", "SCHEMA")
          # Set the local connection cache to 2000 pages
          # https://www.sqlite.org/pragma.html#pragma_cache_size
          raw_execute("PRAGMA cache_size = 2000", "SCHEMA")
        end