org.apache.calcite.plan

Class Strong

java.lang.Object

org.apache.calcite.plan.Strong

public class Strong
extends Object

Utilities for strong predicates.

A predicate is strong (or null-rejecting) if it is UNKNOWN if any of its inputs is UNKNOWN.

By the way, UNKNOWN is just the boolean form of NULL.

Examples:

• UNKNOWN is strong
• c = 1 is strong
• c IS NULL is not strong. (It always returns TRUE or FALSE.)
• p1 AND p2 is strong if p1 or p2 are strong
• p1 OR p2 is strong if p1 and p2 are strong
• c1 = 1 OR c2 IS NULL is strong on c1 but not c2

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	is(RexNode node, ImmutableBitSet nullColumns) Returns whether the analyzed expression will return null if a given set of input columns are null.
static Strong	of(ImmutableBitSet nullColumns)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

of

public static Strong of(ImmutableBitSet nullColumns)

is

public static boolean is(RexNode node,
         ImmutableBitSet nullColumns)

Returns whether the analyzed expression will return null if a given set of input columns are null.