Expand Unary Logical Operator¶

Expand is a unary logical operator that represents Cube, Rollup, GroupingSets and TimeWindow logical operators after they have been resolved at analysis phase.

Creating Instance¶

Expand takes the following to be created:

• Projections (Seq[Seq[Expression]])
• Output Attributes
• Child LogicalPlan

Expand is created when:

• ResolveUnpivot logical resolution rule is executed (to resolve Unpivot expression)
• TimeWindowing logical resolution rule is executed (to resolve TimeWindow expressions)
• RewriteUpdateTable logical resolution rule is executed (to buildDeletesAndInserts)
• Expand is requested to apply

Creating Expand¶

apply(
  groupingSetsAttrs: Seq[Seq[Attribute]],
  groupByAliases: Seq[Alias],
  groupByAttrs: Seq[Attribute],
  gid: Attribute,
  child: LogicalPlan): Expand

apply...FIXME

apply is used when:

• ResolveGroupingAnalytics logical analysis rule is executed

Analysis Phase¶

Expand logical operator is resolved at analysis phase in the following logical evaluation rules:

• ResolveGroupingAnalytics (for Cube, Rollup, GroupingSets logical operators)
• ResolveUnpivot
• RewriteUpdateTable
• TimeWindowing (for TimeWindow logical operator)

Physical Planning¶

Expand logical operator is resolved to ExpandExec physical operator in BasicOperators execution planning strategy.