A serde is actually used the other way around... Hive parses the query, writes MapReduce code to solve the query, and the generated code uses the serde for field access.
Standard way to write a serde is to start from the trunk regex serde, then modify as needed...
Also, nice article by Roberto Congiu...
Nuance R&D Data Team
From: John Omernik [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, October 16, 2012 11:30 AM
To: [EMAIL PROTECTED]
Subject: Writing Custom Serdes for Hive
We have a maybe obvious question about a serde. When a serde in invoked, does it have access to the original hive query? Ideally the original query could provide the Serde some hints on how to access the data on the backend.
Also, are there any good links/documention on how to write Serdes? Kinda hard to google on for some reason.