public void getAlterTableStmtUniqueConstraint(UniqueConstraint uq, List<String> constraints) {
    if (!UniqueConstraint.isNotEmpty(uq)) {
      return;
    }
    Map<String, List<UniqueConstraint.UniqueConstraintCol>> uniqueConstraints = uq.getUniqueConstraints();
    for (String key : uniqueConstraints.keySet()) {
      ST command = new ST(ALTER_TABLE_ADD_UNIQUE_CONSTRAINT);
      command.add(DATABASE_NAME, unparseIdentifier(uq.getDatabaseName()));
      command.add(TABLE_NAME, unparseIdentifier(uq.getTableName()));
      command.add(CONSTRAINT_NAME, unparseIdentifier(key));
      List<String> colNames = new ArrayList<>();
      for (UniqueConstraint.UniqueConstraintCol col : uniqueConstraints.get(key)) {
        colNames.add(col.colName);
      }
      command.add(COLUMN_NAME, unparseListOfIdentifiersAndJoin(colNames, ","));
      command.add(ENABLE, uniqueConstraints.get(key).get(0).enable);
      command.add(VALIDATE, uniqueConstraints.get(key).get(0).validate);
      command.add(RELY, uniqueConstraints.get(key).get(0).rely);
      constraints.add(command.render());
    }
  }
Parses the basic table statistics for the given table.

@param tbl
@return Returns the alter table .... update statistics for table
ql/src/java/org/apache/hadoop/hive/ql/exec/DDLPlanUtils.java