[IMPALA-9531] Drop support for "dateless timestamps"

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: Impala 4.0.0
• Component/s: Backend
• Target Version: Impala 4.0.0
• Epic Color: ghx-label-10
• Assignee: Adam Tamas
• Reporter: Csaba Ringhofer
• Created: 18/Mar/20 14:44
• Updated: 27/Mar/23 23:01
• Resolved: 13/Jul/20 11:40

Description

Currently cast("15:42:00" as timestamp) doesn't return NULL, but it should, as the resulting timestamps are more or less useless:

• other fileformats than text do not support them
• most built-in unctions don't support them - even those where it could make sense

IMPALA-5942 contains more details about these issues.

Issue Links

• breaks: IMPALA-11355 Add STRING overloads for functions that consume time of day
• causes: IMPALA-9941 ExprTest.CastExprs fails when running with ASAN
• causes: IMPALA-9950 Impala Doc: Update docs for dropped dateless timestamps.
• relates to: IMPALA-5942 Dateless timestamps (e.g. "10:00:00") are handled inconsistently