Interface Statistic

public interface Statistic
Statistics about a Table.

Each of the methods may return null meaning "not known".

See Also:
  • Method Details

    • getRowCount

      default @Nullable Double getRowCount()
      Returns the approximate number of rows in the table.
    • isKey

      default boolean isKey(ImmutableBitSet columns)
      Returns whether the given set of columns is a unique key, or a superset of a unique key, of the table.
    • getKeys

      default @Nullable List<ImmutableBitSet> getKeys()
      Returns a list of unique keys, or null if no key exist.
    • getReferentialConstraints

      default @Nullable List<RelReferentialConstraint> getReferentialConstraints()
      Returns the collection of referential constraints (foreign-keys) for this table.
    • getCollations

      default @Nullable List<RelCollation> getCollations()
      Returns the collections of columns on which this table is sorted.
    • getDistribution

      default @Nullable RelDistribution getDistribution()
      Returns the distribution of the data in this table.