With ALTER SESSION DESCRIBE STATEMENT a number of problems with extended
timestamp format will be gone automatically. But one of key problems
remains - what can client do with timezone code when it does not know
conversion rule for it.
A nice solutipn was already suggested by Vlad - extend timestamp with
timezone with 2 bytes and always send offset to client in them. This
format does not require any tuning and is a real 'brute-force' solution
for a problem with unknown to client timezone code. When sending data in
reverse direction (from client to server) server is using timezone code
when it's present (i.e. offset is ignored), otherwise - offset.
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