class SqlLatticeStatisticProvider extends java.lang.Object implements LatticeStatisticProvider
LatticeStatisticProvider
that gets statistics by
executing "SELECT COUNT(DISTINCT ...) ..." SQL queries.LatticeStatisticProvider.Factory
Modifier and Type | Field and Description |
---|---|
(package private) static LatticeStatisticProvider.Factory |
CACHED_FACTORY |
(package private) static LatticeStatisticProvider.Factory |
FACTORY |
private Lattice |
lattice |
Modifier | Constructor and Description |
---|---|
private |
SqlLatticeStatisticProvider(Lattice lattice)
Creates a SqlLatticeStatisticProvider.
|
Modifier and Type | Method and Description |
---|---|
private double |
cardinality(Lattice lattice,
Lattice.Column column) |
double |
cardinality(java.util.List<Lattice.Column> columns)
Returns an estimate of the number of distinct values in a column
or list of columns.
|
static final LatticeStatisticProvider.Factory FACTORY
static final LatticeStatisticProvider.Factory CACHED_FACTORY
private final Lattice lattice
private SqlLatticeStatisticProvider(Lattice lattice)
public double cardinality(java.util.List<Lattice.Column> columns)
LatticeStatisticProvider
cardinality
in interface LatticeStatisticProvider
private double cardinality(Lattice lattice, Lattice.Column column)
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