private void applyContantPartition(WindowSpec wdwSpec) {
PartitionSpec partSpec = wdwSpec.getPartition();
if ( partSpec == null ) {
partSpec = new PartitionSpec();
PartitionExpression partExpr = new PartitionExpression();
partExpr.setExpression(new ASTNode(new CommonToken(HiveParser.Number, "0")));
partSpec.addExpression(partExpr);
wdwSpec.setPartition(partSpec);
}
}