I have written two conversion rules to test my custom TableScan and Project
on Volcano (I use as Convention: new Convention.Impl("LOGICAL",
SaberRel.class)). To begin with, I want only to convert the initial logical
rules of Calcite to my custom logical rules. I have added to my planner the
two conversion rules with AbstractConverter.ExpandConversionRule.INSTANCE.
However, I get this error:
Exception in thread "main"
org.apache.calcite.plan.RelOptPlanner$CannotPlanException: Node
[rel#8:Subset#0.ENUMERABLE.[]] could not be implemented; planner state:
Root: rel#8:Subset#0.ENUMERABLE.[]
Original rel:
Sets:
Set#0, type: RecordType(TIMESTAMP(0) rowtime, INTEGER productid, INTEGER
description)
rel#4:Subset#0.NONE.[0], best=null, importance=0.0
rel#2:LogicalTableScan.NONE.[[0]](table=[s, products]), rowcount=16384.0,
cumulative cost={inf}
rel#5:LogicalProject.NONE.[[0]](input=rel#4:Subset#0.NONE.[0],rowtime=$0,productid=$1,description=$2),
rowcount=16384.0, cumulative cost={inf}
rel#8:Subset#0.ENUMERABLE.[], best=null, importance=0.0
rel#10:Subset#0.LOGICAL.[0], best=rel#9, importance=0.0
rel#9:SaberTableScanRel.LOGICAL.[[0]](table=[s, products]),
rowcount=16384.0, cumulative cost={16384.0 rows, 16385.0 cpu, 0.0 io,
16384.0 rate, 0.0 memory, 0.0 window, 0.0 network}
rel#11:SaberProjectRel.LOGICAL.[[0]](input=rel#10:Subset#0.LOGICAL.[0],rowtime=$0,productid=$1,description=$2),
rowcount=16384.0, cumulative cost={32768.0 rows, 147457.0 cpu, 0.0 io,
16384.0 rate, 0.0 memory, 1.0 window, 0.0 network}
at
org.apache.calcite.plan.volcano.RelSubset$CheapestPlanReplacer.visit(RelSubset.java:443)
at
org.apache.calcite.plan.volcano.RelSubset.buildCheapestPlan(RelSubset.java:293)
at
org.apache.calcite.plan.volcano.VolcanoPlanner.findBestExp(VolcanoPlanner.java:835)
at org.apache.calcite.tools.Programs$RuleSetProgram.run(Programs.java:334)
at org.apache.calcite.prepare.PlannerImpl.transform(PlannerImpl.java:308)
at calcite.planner.SaberPlanner.getLogicalPlan(SaberPlanner.java:309)
at calcite.Tester.main(Tester.java:70)
Why does it still try to implement Enumerable convention? When I add the
Enumerable rules I get the Enumerable logical plan and not my custom. What
should I do?
2016-12-17 22:11 GMT+02:00 Γιώργος Θεοδωράκης <giwrgosrth...@gmail.com>:
> Hello,
>
> I think I have understood the basics about RelOptCost, transformer and
> converter rules and how to use them in Volcano in order to set my own
> cost-model, from examples I have seen in Drill and Hive mainly.
> As I am thinking about t it right now, I should:
> 1)define my cost model and optimization goal (Volcano uses Lt method) in a
> CustomCostBase class that implements RelOptCost
> 2)define my operators with the same logic as they are and override their
> computeCost method
> 3)define my proper converter and transform rules
>
> However, in order to use Volcano, I have to use some rules with Convention
> that is not NONE. So I think I have to implement my own custom Convention
> that my rules should have and convert the logical rules to my custom ones.
> Then enforce my rules on these custom rules and get an optimized plan.
>
> Do I miss something in the logic I describe above? Do you have any
> suggestions on how to do it in another way?
>
> Thank you in advance,
> George
>
>
