Hi, is it possible to write a SerDe (or something else) so that DESCRIBE <table> (as we all query parser) get the column definitions from the SerDe rather than Metastore?
The idea is to support self-describing data types such as JSON such that when the per partition schema changes, there is no need to run an ALTER TABLE to access new fields. For example, partition 1 of table T has JSON docs with fields 'a', 'b', 'c' and the table was created with schema that has 3 columns. Let's say later a partition is added where the docs have fields 'a', 'b', 'c', 'd'. Is it possible to then run a query 'SELECT T.d from T' w/o ALTER TABLE? (assuming SerDe is smart enough to produce NULL for row that don't have this field) Is there a mechanism for that? Thank you, Eugene -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
