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0d7787fe4d
This change allows casting of a string in 'lazy' date/time format to timestamp. The supported lazy date formats are: yyyy-[M]M-[d]d yyyy-[M]M-[d]d [H]H:[m]m:[s]s[.SSSSSSSSS] [H]H:[m]m:[s]s[.SSSSSSSSS] We will incur a SCAN performance penalty (approximately 1/2 TotalReadThroughput) when the string is in one of these lazy date/time format. Testing: Benchmarked the performance consequence by executing this SQL on a private build over 3.8 billion rows: select min(cast (time_string as timestamp)) from private.impala_5315 Added tests for valid and invalid date/time format strings in expr-test.cc to be inline with existing tests for CAST() function. Added end-to-end tests into exprs.test and select-lazy-timestamp.test to exercise the new function within the context of a query. Added tests to exercise the leading and trailing white space trimming behaviour in default and lazy date/time string format (IMPALA-6630). Change-Id: Ib9a184a09d7e7783f04d47588537612c2ecec28f Reviewed-on: http://gerrit.cloudera.org:8080/7009 Reviewed-by: Tim Armstrong <tarmstrong@cloudera.com> Tested-by: Impala Public Jenkins