On Fri, 1 Mar 2019 at 15:27, Richard Guo <ri...@pivotal.io> wrote: > I have reviewed your patch. Good job except two issues I can find: > > 1. The patch would give wrong results when the inner side is empty. In this > case, the whole data from outer side should be in the outputs. But with the > patch, we will lose the NULLs from outer side. > > 2. Because of the new added predicate 'OR (var is NULL)', we cannot use hash > join or merge join to do the ANTI JOIN. Nested loop becomes the only choice, > which is low-efficency.
Yeah. Both of these seem pretty fundamental, so setting the patch to waiting on author. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
