@Sura Reddy Have you tried with
// Next change column a1's name to a2, its data type to string, and put it after column b.
ALTER TABLE test_change CHANGE a1 a2 STRING AFTER b;
This is documented as part of https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL#LanguageManualDDL-AlterTableProp...
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