Optimizer pattern match based on the plan node traits

[Shylock-Hg]

Introduction

E.G. match any sorted output node, match any storage access node etc.

e.g. limit push down pattern and transformation

limit-><kSameInputOutputRows>  --> <kSameInputOutputRows>->limit
limit-><kExplore --> limit-><kExplore + limit>

kSameInputOuptputRows is the trait means the plan node keep rows of input and output same.
kExplore is the trait means the plan node access to storage.

Why need it

Our current optimizer rule can't cover many plan.
Decouple plan node and optimize rule.
Reduce optimize rules , reduce duplicate code, improve optimizer performance.

Contents

Related work