private static void constraintInfosToUniqueConstraints(TableName tableName, List<ConstraintInfo> uniqueInfos,
      List<SQLUniqueConstraint> uniqueConstraints) {
    int i = 1;
    for (ConstraintInfo uniqueInfo : uniqueInfos) {
      uniqueConstraints.add(new SQLUniqueConstraint(tableName.getCat(), tableName.getDb(), tableName.getTable(),
          uniqueInfo.colName, i++, uniqueInfo.constraintName, uniqueInfo.enable, uniqueInfo.validate, uniqueInfo.rely));
    }
  }
Process the unique constraints from the ast node and populate the SQLUniqueConstraint list.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/constraint/ConstraintsUtils.java