Question
Why does Impala 2.0 regex .*? behavior differ from a typical implementation
From the docs at https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/impala_string_functions.html#string_functions__regexp_extract
"This example shows how a pattern string starting with .*? matches the shortest possible portion of the source string, returning the rightmost set of lowercase letters."
select regexp_extract('AbcdBCdefGHI','.*?([[:lower:]]+)',1);
returns def
Every other Regex impl I've worked with would return bcd
I can't make sense of the docs either - "shortest possible string.. returns the rightmost.." - the shortest possible string in a "search from the left" operation returns the leftmost, not the rightmost
