The equality parition filter of partition selector works very well for single
level partition table, but if the table has multilevel partitions, e.g. 2
levels with pk1, pk2 as the partition key for level 1 and 2, and there is a
equality predicate in the query, say pk1 = 2, then level 2 equality filter is null,
the function `FEqPartFiltersAllLevels` will return false, causing the equality
predicate put into PartFilters instead of PartEqFilters. This bug has been
fixed in the patch.

[#141826453]