CollectColumnsInExtendedStats returns IDs of the columns involved in extended stats.

GetPredicateColumns returns IDs of predicate columns, which are the columns whose stats are used(needed) when generating query plans.

LoadColumnStatsUsage loads column stats usage information from disk.

LoadColumnStatsUsageForTable loads column stats usage information for a specific table from disk.

SaveColumnStatsUsageForTable saves column stats usage information for a specific table to disk.