public static String unescapeIdentifier(String val) {
    if (val == null) {
      return null;
    }
    if (val.charAt(0) == '`' && val.charAt(val.length() - 1) == '`') {
      val = val.substring(1, val.length() - 1);
    }
    return val;
  }
Remove the encapsulating "`" pair from the identifier. We allow users to
use "`" to escape identifier for table names, column names and aliases, in
case that coincide with Hive language keywords.
ql/src/java/org/apache/hadoop/hive/ql/parse/BaseSemanticAnalyzer.java