A PDA Extract Procedure is run to collect statistics on tablespaces only, without their associated indexes. It also, at the same time, updates the DB2 catalog to mimic what RUNSTATS does, in theory, with COLSTATS=I(ndex) defined.
SYSCOLUMNS is updated with blank values in HIGH2KEY and LOW2KEY.
This may cause the optimizer to make some unfortunate access path choices in some cases.
This problem is caused by using Database Analyzer in a way other than how it is designed to work.
There are two options to resolve this problem:
Typically you would want your Tablespace/Table statistics to stay in sync with their corresponding Indexes statistics so that the DB2 optimizer is fed valid info.