Disable prepared statement cache

src/db/connection.cr

@@ -25,7 +25,6 @@ module DB
 
     # :nodoc:
     getter context
-    @statements_cache = StringKeyCache(Statement).new
     @transaction = false
     getter? prepared_statements : Bool
     # :nodoc:
@@ -37,7 +36,7 @@ module DB
 
     # :nodoc:
     def fetch_or_build_prepared_statement(query) : Statement
-      @statements_cache.fetch(query) { build_prepared_statement(query) }
+      build_prepared_statement(query)
     end
 
     # :nodoc:
@@ -57,8 +56,6 @@ module DB
     end
 
     protected def do_close
-      @statements_cache.each_value &.close
-      @statements_cache.clear
       @context.discard self
     end
 

src/db/pool_prepared_statement.cr

@@ -5,61 +5,24 @@ module DB
   #
   # See `PoolStatement`
   class PoolPreparedStatement < PoolStatement
-    # connections where the statement was prepared
-    @connections = Set(WeakRef(Connection)).new
-    @mutex = Mutex.new
-
     def initialize(db : Database, query : String)
       super
-      # Prepares a statement on some connection
-      # otherwise the preparation is delayed until the first execution.
-      # After the first initialization the connection must be released
-      # it will be checked out when executing it.
-      statement_with_retry &.release_connection
-      # TODO use a round-robin selection in the pool so multiple sequentially
-      #      initialized statements are assigned to different connections.
     end
 
     protected def do_close
-      @mutex.synchronize do
-        # TODO close all statements on all connections.
-        # currently statements are closed when the connection is closed.
-
-        # WHAT-IF the connection is busy? Should each statement be able to
-        # deallocate itself when the connection is free.
-        @connections.clear
-      end
     end
 
     # builds a statement over a real connection
     # the connection is registered in `@connections`
     private def build_statement : Statement
-      clean_connections
+      conn = @db.checkout
-      conn, existing = @db.checkout_some(@connections)
       begin
         stmt = conn.prepared.build(@query)
       rescue ex
         conn.release
         raise ex
       end
-      unless existing
-        @mutex.synchronize do
-          @connections << WeakRef.new(conn)
-        end
-      end
       stmt
     end
-
-    private def clean_connections
-      @mutex.synchronize do
-        # remove disposed or closed connections
-        @connections.each do |ref|
-          conn = ref.value
-          if !conn || conn.closed?
-            @connections.delete ref
-          end
-        end
-      end
-    end
   end
 end