Interface BuiltInMetadata.UniqueKeys

    • Method Detail

      • getUniqueKeys

        java.util.Set<ImmutableBitSet> getUniqueKeys​(boolean ignoreNulls)
        Determines the set of unique minimal keys for this expression. A key is represented as an ImmutableBitSet, where each bit position represents a 0-based output column ordinal.

        Nulls can be ignored if the relational expression has filtered out null values.

        ignoreNulls - if true, ignore null values when determining whether the keys are unique
        set of keys, or null if this information cannot be determined (whereas empty set indicates definitely no keys at all)