Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive, mail # user - hive map field question


Copy link to this message
-
RE: hive map field question
Chalcy Raja 2011-11-23, 16:14
Thanks, Mark.  I'll try that.  

Also, is there a way to list all the keys and values in a map field?

Thanks,
Chalcy

-----Original Message-----
From: Mark Grover [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, November 23, 2011 11:01 AM
To: [EMAIL PROTECTED]
Subject: Re: hive map field question

Hi Chalcy,
You could write a UDF that takes in a Map object and returns you the string you need.

Alternatively, you could use Hive Transform. Details here:https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Transform

When a map gets passed to your custom transform script, you could read it as a serialized string.

Mark

----- Original Message -----
From: "Chalcy Raja" <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Sent: Wednesday, November 23, 2011 10:48:07 AM
Subject: hive map field question
Hello HiveUsers,

I have a need to convert a map<string,string> field to string field and vice versa in a hive table. I could not do cast.

I created two external tables with one has string and another map. I can join both to get what I want, takes a long time.

Any ideas of how it can be done efficiently ?

Thanks,

Chalcy