Examples of com.foundationdb.sql.optimizer.DistinctEliminator

com.foundationdb.sql.optimizer.DistinctEliminator

Eliminate DISTINCT from SELECT when result is already distinct. Derby has a somewhat different version of this, but it does not try multiple result tables or outer joins. It would be nicer if this could be an actual rule, but it really has to run before ASTStatementLoader to keep from trying to sort on all the extra columns. Likewise, if this runs before SubqueryFlattener, it can remove a DISTINCT from a derived table and allow it to flatten. If it runs after, it will not be stopped by derived tables that do get flattened. Really, the two need to cooperate more closely.

        compilerProperties = new Properties();
        unparser = new BoundNodeToString();
        typeComputer = new AISTypeComputer();
        booleanNormalizer = new BooleanNormalizer(parser);
        subqueryFlattener = new SubqueryFlattener(parser);
        distinctEliminator = new DistinctEliminator(parser);
    }

Examples of com.foundationdb.sql.optimizer.DistinctEliminator

Related Classes of com.foundationdb.sql.optimizer.DistinctEliminator