Julian Hyde created CALCITE-828:
-----------------------------------
Summary: Change all built-in rules to use a RelBuilder rather than
type-specific RelNode factories
Key: CALCITE-828
URL: https://issues.apache.org/jira/browse/CALCITE-828
Project: Calcite
Issue Type: Bug
Reporter: Julian Hyde
Assignee: Julian Hyde
Many planner rules create filters, projects, joins, ... and over the years
people have made them generic, so they can create different particular
sub-classes of RelNodes (say DrillFilter or HiveProject) by adding factories
(interfaces defined in RelFactories).
But then people extend a rule, so that a rule that used to only create projects
now might sometimes create a filter. They now need to add an extra parameter to
the instance of the rule, which is painful. Also, rules may call into utility
methods such as RelOptUtil.pushDownJoinConditions (see CALCITE-826), which have
similar problems.
The solution is to get rid of factories in public interfaces and instead pass
around a RelBuilder. A particular instance of RelBuilder has a factory inside
it for each type of RelNode. In general a particular client of Calcite (e.g.
Hive) will be able to use the same RelBuilder throughout a query.
Rules are static, so a rule instance cannot contain a RelBuilder, only a
ProtoRelBuilder, which can create a RelBuilder given a RelOptCluster and
RelOptSchema.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
