Make NULL tuple values always advance skip arrays. _bt_check_compare neglected to handle a case that can arise when the scan's keys are temporarily treated as nonrequired, as an optimization: whenever a NULL tuple value was encountered that had a skip array whose current element wasn't already NULL, _bt_check_compare failed to advance the array to the NULL element. This allowed _bt_check_compare to fail to return matching tuples containing a NULL value (though only with an array column that came before a skip array column with NULLs, and only during _bt_readpage calls that set pstate.forcenonrequired=true on a page where the higher-order column also had to advance).
To fix, teach _bt_check_compare to handle this case just like any other case where a skip array key is unsatisfied and must be advanced directly (due to the key being considered a nonrequired key). Oversight in commit 8a510275, which optimized nbtree search scan key comparisons with skip arrays. Author: Peter Geoghegan <p...@bowt.ie> Reported-By: Mark Dilger <mark.dil...@enterprisedb.com> Discussion: https://postgr.es/m/cahghdktlfwzcjr87hmh0hydhgcifu4tj7ihz-xh8qsjret5...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/b75fedcab7916e1c955dbab565b7ad0cee6b37c6 Modified Files -------------- src/backend/access/nbtree/nbtutils.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
