I would +1 (1-3) for sure. I do not have much understanding of programs however additional flexibility for storage plugin devs sounds cool in general when used responsibly =) so +0 for (4)
-H+ On Mon, Oct 12, 2015 at 4:12 PM, Jacques Nadeau <[email protected]> wrote: > The dead air must mean that everyone is onboard with my recommendation > > PlannerIntegration StoragePlugin.getPlannerIntegrations() > > interface PlannerIntegration{ > void initialize(Planner, Phase) > } > > Right :D > > -- > Jacques Nadeau > CTO and Co-Founder, Dremio > > On Fri, Oct 9, 2015 at 7:03 AM, Jacques Nadeau <[email protected]> wrote: > > > A number of us were meeting last week to work through integrating the > > Phoenix storage plugin. This plugin is interesting because it also uses > > Calcite for planning. In some ways, this should make integration easy. > > However, it also allowed us to see certain constraints who how we expose > > planner integration between storage plugins and Drill internals. > > Currently, Drill asks the plugin to provide a set of optimizer rules > which > > it incorporates into one of the many stages of planning. This is too > > constraining in two ways: > > > > 1. it doesn't allow a plugin to decide which phase of planning to > > integrate with. (This was definitely a problem in the Phoenix case. Our > > hack solution for now is to incorporate storage plugin rules in phases > > instead of just one [1].) > > 2. it doesn't allow arbitrary transformations. Calcite provides a program > > concept. It may be that a plugin needs to do some of its own work using > the > > Hep planner. Currently there isn't an elegant way to do this in the > context > > of the rule. > > 3. There is no easy way to incorporate additional planner initialization > > options. This was almost a problem in the case of the JDBC plugin. It > > turned out that a hidden integration using register() here [2] allowed us > > to continue throughout the planning phases. However, we have to register > > all the rules for all the phases of planning which is a bit unclean. > We're > > hitting the same problem in the case of Phoenix where we need to register > > materialized views as part of planner initialization but the hack from > the > > JDBC case won't really work. > > > > I suggest we update the interface to allow better support for these types > > of integrations. > > > > These seem to be the main requirements: > > 1. Expose concrete planning phases to storage plugins > > 2. Allow a storage plugin to provide additional planner initialization > > behavior > > 3. Allow a storage plugin to provide rules to include a particular > > planning phase (merged with other rules during that phase). > > 4. (possibly) allow a storage plugin to provide transformation programs > > that are to be executed in between the concrete planning phases. > > > > Item (4) above is the most questionable to me as I wonder whether or not > > this could simply be solved by creating a transformation rule (or program > > rule in Calcite's terminology) that creates an alternative tree and thus > be > > solved by (3). > > > > A simple solution might be (if we ignore #4): > > > > PlannerIntegration StoragePlugin.getPlannerIntegrations() > > > > interface PlannerIntegration{ > > void initialize(Planner, Phase) > > } > > > > This way, a storage plugin could register rules (or materialized views) > at > > setup time. > > > > What do others think? > > > > [1] > > > https://github.com/apache/drill/blob/master/contrib/storage-jdbc/src/main/java/org/apache/drill/exec/store/jdbc/JdbcStoragePlugin.java#L145 > > [2] > > > https://github.com/jacques-n/drill/commit/d463f9098ef63b9a2844206950334cb16fc00327#diff-e67ba82ec2fbb8bc15eed30ec6a5379cR119 > > > > -- > > Jacques Nadeau > > CTO and Co-Founder, Dremio > > >
