io.prestosql.sql.planner

Class NullabilityAnalyzer

java.lang.Object

io.prestosql.sql.planner.NullabilityAnalyzer

public final class NullabilityAnalyzer
extends Object

Method Summary

Modifier and Type	Method and Description
static boolean	mayReturnNullOnNonNullInput(Expression expression) TODO: this currently produces a very conservative estimate.

Methods inherited from class java.lang.Object

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

Method Detail

mayReturnNullOnNonNullInput

public static boolean mayReturnNullOnNonNullInput(Expression expression)

TODO: this currently produces a very conservative estimate. We need to narrow down the conditions under which certain constructs can return null (e.g., if(a, b, c) might return null for non-null a only if b or c can be null.