Parameter queries can only be implemented by using a stored query. Because stored queries have a precompiled query plan, parameter queries that contain parameters on indexed fields may not execute efficiently. Because the query engine does not know the values to be passed in a parameter in advance, it can only guess as to the most efficient query plan. In some instances, you can substantially improve performance by replacing a stored parameter query with a temporary query. To do this, create the SQL string in code and pass it to the Database object’s OpenRecordset method or Execute method.