WindowFunction Expressions¶

WindowFunction is an extension of the Expression abstraction for window functions.

WindowFunction (along with AggregateFunction) is of SQL window function type.

OVER Clause¶

WindowFunction can only be evaluated in the context of OVER window operator.

CheckAnalysis enforces that WindowFunctions can only be children of WindowExpression.

Implementations¶

• AggregateWindowFunction
• OffsetWindowFunction

Logical Resolution Rules¶

Analyzer uses the following rules to work with WindowFunctions:

1. ResolveWindowFrame
2. ResolveWindowOrder
3. ExtractWindowExpressions

WindowFrame¶

frame: WindowFrame

frame is an UnspecifiedFrame by default.

See:

• AggregateWindowFunction

frame is used when:

• ResolveWindowFrame logical resolution rule is executed