[IMPALA-7060] Restrict Impala to only support timezones that work in Hive (IANA + Java)

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Won't Do
• Component/s: Backend
• Epic Color: ghx-label-1
• Assignee: Csaba Ringhofer
• Reporter: Csaba Ringhofer
• Created: 23/May/18 16:29
• Updated: 05/Nov/18 19:49
• Resolved: 03/Jul/18 16:57

Description

IANA timezone integration (IMPALA-3307) will drop the support for many non-standard timezone aliases. As IMPALA-3307 is a very large change, its release may be delayed - meanwhile, it would be better to discourage Impala 3.x users from using timezone names that will not be supported in the future. For this reason, the current boost based implementation could drop the support for non-standard aliases.

Note that the current implementation has some major issues:

• Some of the aliases are ambiguous - Impala will always interpret it the same way, but this is based on an arbitrary ordering of timezones, so the timezone may be actually different than what the user wanted. I think that it is better the print a warning in this case.
• If the name is not among the standard names, the lookup among aliases is extremely slow (linear search on all supported standard timezones).
• Most of the aliases are not covered by test cases.

Issue Links

• is related to: IMPALA-3307 add support for IANA time zone database
• relates to: IMPALA-7123 Impala 3.1 or 4.0 Doc: Restrict Impala to only support timezones that work in Hive (IANA + Java)