KUDU-3518: Fix the unexpected scan predicate

With the changes introduced in a previous patch[1], there have been
reports of errors during scan operations. This patch fixes these
scan errors.

This patch removes NON-NULL predicates on primary columns implicitly 
added by ScanSpec::LiftPrimaryKeyBounds(), calling  
ScanSpec::OptimizeScan() while optimizing InList scan predicates at the 
DRS level.  That's similar to what's done be optimizing the InList 
predicates based on tablet PK bounds at a higher level.

The issue has been investigated and fixed in collaboration with Alexey 
Serbin.

There will be follow-up patches to include tests of this failure.

[1] https://gerrit.cloudera.org/#/c/18434/

Change-Id: I220df7ec1b4f95726c913a19125f4647267d12b1
Reviewed-on: http://gerrit.cloudera.org:8080/21244
Reviewed-by: Alexey Serbin <alexey@apache.org>
Tested-by: Alexey Serbin <alexey@apache.org>
Reviewed-by: Yifan Zhang <chinazhangyifan@163.com>
1 file changed