Memory usage with high # of predicates

[justin13601]

Possible area of enhancement regarding memory usage when a high number of predicates is specified.

I remember when I profiled, the memory peaked during the creation of the predicate columns.

@Jwoo5 could you please help confirm if this is the case for your dataset/tasks as well? I just used mprof to run a script with the extraction code and looked at the memory plots.

Tagging @mmcdermott