Hi, Thanks Jov and Ajo
Changing from Union to Union all solved the issue. But do we need to specify all the fields in the sub query? Actually I had used the following query. INSERT OVERWRITE TABLE tab3 SELECT t3.col1,t3col2 FROM (SELECT id AS col1,name AS col2 FROM tab1 UNION ALL SELECT id AS col1,name as col2 FROM tab2)t3; The above query overwrite the result in the table tab3. If I am doing such an operation in a table that has many fields,Is it necessary to specify all the column names as a part of the sub query? If not, Will the query *SELECT t3.* FROM (SELECT * FROM tab1 UNION ALL SELECT * FROM tab2)t3;* work?As I am using this to update my table which has many columns,I need this. Well,I will check it first and get back to you. Thank you, 2011/2/18 Jov <zhao6...@gmail.com> > hive0.4.1 do not support union,only support union all > 在 2011-2-18 下午3:12，"sangeetha s" <sangee....@gmail.com>写道： > > > > > Hi, > > > > I am trying to perform union of two tables which are having identical > > schemas and distinct data.There are two tables 'oldtable' and 'newtable'. > > The old table contains the information of old users and the new table > will > > conatin the information of new user. I am trying to update the new entry > in > > the old table using the following query. > > > > INSERT OVERWRITE TABLE oldtable SELECT * FROM (SELECT * FROM oldtable > UNION > > select * from newtable); > > > > executing the above query results, > > FAILED:Parse Error:line 1.68 mismatched input 'select' expecting ALL in > > query operator. > > > > I am currently using Hadoop verso 0.20.2 and Hive 0.4.1 from apache > > disctribution. Will Hive 0.4.1 support UNION and UNION ALL queries? Is > the > > above problem is dueto the Hive version or due to a wrong query? Also I > am > > not using any partitions in these tables and the table format is > TextFile. > > > > Any pointers in this regard would be highly helpful. > > > > -- > > > > > > > > Regards, > > Sangita > > > > > > -- > > > -- Regards, Sangita
