Use existing unique indexes as PK evidence for tables with no declared primary key (default true):
a unique index on NOT NULL columns becomes a candidate even when the statistics can't show
uniqueness (e.g. an empty table), and composite unique indexes are considered when no single column
qualifies (next to a qualifying single-column key they are alternate keys and are not added).
Needs analysis.useExistingIndexes (also default true).
Use existing unique indexes as PK evidence for tables with no declared primary key (default true): a unique index on NOT NULL columns becomes a candidate even when the statistics can't show uniqueness (e.g. an empty table), and composite unique indexes are considered when no single column qualifies (next to a qualifying single-column key they are alternate keys and are not added). Needs
analysis.useExistingIndexes(also default true).