mt.setLeftExpression(_columnOrderdate);
mt.setRightExpression(new DateValue(" 1995-01-01 "));
String path = "../test/squall/schemas/tpch.txt";
double scallingFactor = 1;
_selEstimator = new SelingerSelectivityEstimator("TEST", new Schema(path, scallingFactor), new TableAliasName(tableList, "SelingerTest"));
}