mirror of
https://github.com/apache/impala.git
synced 2025-12-23 21:08:39 -05:00
a862282811
This patch adds new built-in functions to calculate restricted Damerau-Levenshtein edit distance (optimal string alignment). Implmented as dle_dst() and damerau_levenshtein(). If either value is NULL or both values are NULL returns NULL which differs from Netezza's dle_dst() which returns the length of the not NULL value or 0 if both values are NULL. The NULL behavior matches the existing levenshtein() function. Also cleans up levenshtein tests. Testing: - Added unit tests to expr-test.cc - Manual testing on over 1400 string pairs from http://marvin.cs.uidaho.edu/misspell.html and results match Netezza Change-Id: Ib759817ec15e7075bf49d51e494e45c8af4db94d Reviewed-on: http://gerrit.cloudera.org:8080/13794 Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Reviewed-by: Csaba Ringhofer <csringhofer@cloudera.com> Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>