private static AlterTableExecuteDesc getSetCurrentSnapshotDesc(TableName tableName, Map<String, String> partitionSpec,
      ASTNode childNode) throws SemanticException {
    AlterTableExecuteSpec<AlterTableExecuteSpec.SetCurrentSnapshotSpec> spec =
        new AlterTableExecuteSpec(SET_CURRENT_SNAPSHOT,
            new AlterTableExecuteSpec.SetCurrentSnapshotSpec(childNode.getText()));
    return new AlterTableExecuteDesc(tableName, partitionSpec, spec);
  }
Analyzer for ALTER TABLE ... EXECUTE commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/execute/AlterTableExecuteAnalyzer.java