hive-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Raghunath, Ranjith" <>
Subject Re: External tables pros & cons
Date Tue, 26 Apr 2011 16:42:43 GMT
From my understanding of external tables they are great if we need multiple schemas associated
with the same base data. A place where this could come handy is if we using custom SerDe implementation.
The drawback that I have noticed has to do with binary file formats. One will have to use
a custom map reduce job to generate the base data if you plan to use that as an external table.
Please feel free to correct me here if I am wrong.


From: Shantian Purkad <>
To: <>
Sent: Tue Apr 26 11:18:46 2011
Subject: External tables pros & cons


What is the difference between external table and managed tables (apart from data being stored
outside hive warehouse and not deleted when table is dropped)

Are there any drawbacks of external tables? Or lack of support for certain features (such
as indexes, joins, subqueries etc etc )?

When and why should one not use external tables?

Thanks and Regards,
View raw message