That was my understanding, but it seems usage of CalciteSchema is prevalent outside the scope of the JDBC adapter:
$ grep -rl import.*CalciteSchema core/src/main/java|grep -v calcite/jdbc core/src/main/java/org/apache/calcite/materialize/Lattice.java core/src/main/java/org/apache/calcite/materialize/MaterializationActor.java core/src/main/java/org/apache/calcite/materialize/MaterializationService.java core/src/main/java/org/apache/calcite/model/ModelHandler.java core/src/main/java/org/apache/calcite/plan/RelOptLattice.java core/src/main/java/org/apache/calcite/prepare/CalciteCatalogReader.java core/src/main/java/org/apache/calcite/prepare/CalciteMaterializer.java core/src/main/java/org/apache/calcite/prepare/CalcitePrepareImpl.java core/src/main/java/org/apache/calcite/prepare/PlannerImpl.java core/src/main/java/org/apache/calcite/prepare/Prepare.java core/src/main/java/org/apache/calcite/prepare/QueryableRelBuilder.java core/src/main/java/org/apache/calcite/prepare/RelOptTableImpl.java core/src/main/java/org/apache/calcite/rel/rules/AggregateStarTableRule.java core/src/main/java/org/apache/calcite/schema/impl/MaterializedViewTable.java core/src/main/java/org/apache/calcite/schema/impl/ViewTable.java core/src/main/java/org/apache/calcite/schema/impl/ViewTableMacro.java core/src/main/java/org/apache/calcite/schema/Schemas.java core/src/main/java/org/apache/calcite/sql/validate/EmptyScope.java core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorCatalogReader.java core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorImpl.java core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorUtil.java core/src/main/java/org/apache/calcite/tools/Frameworks.java So should we go the opposite way and remove usage of CalciteSchema in calcite core, outside of the JDBC adapter? It looks like some interfaces would have to be extended to replace its use. On Mon, Apr 9, 2018 at 3:23 PM, Julian Hyde <jh...@apache.org> wrote: > The policy that CalciteSchema should be private to Calcite hasn’t changed > (it is a public interface only because… Java). > > It has never been private to the JDBC adapter. (The JDBC adapter readers > from JDBC sources and is in org.apache.calcite.adapter.jdbc, whereas > CalciteSchema is in org.apache.calcite.jdbc, which makes Calcite look like > a JDBC database.) > > CalciteSchema is an abstract class. There are two concrete > implementations: CachingCalciteSchema which remembers what it has read from > the underlying source, and SimpleCalciteSchema that caches nothing. I know > Drill (and I guess now Dremio) has a different policy, so how about adding > an implementation of CalciteSchema that has that policy? I have been asking > for this for a long time. > > If we did what you suggest, and make CalciteSchema (or a base interface of > it) a public API then people will go and create implementations of that > interface that will get broken all the time. > > Julian > > > > On Apr 3, 2018, at 4:10 PM, Laurent Goujon <laur...@dremio.com> wrote: > > > > Hi, > > > > While working on rebasing our code on top of Calcite 1.16, I noticed > that a > > new method was introduced to SqlValidatorCatalogReader: CalciteSchema > > `SqlValidatorCatalogReader#getRootSchema()` (not recently, it was added > for > > Calcite 1.12) > > > > My understanding of CalciteSchema was that this class is private and > > specific to the JDBC adapter, but looking at the code base, I see it used > > in lots of various places. Has the policy changed? if so, would it make > > sense to change it to an interface or to relax the class? The current > model > > where all informations are stored in maps doesn't match our own model of > > navigating our catalog. > > > > Cheers, > > > > Laurent > >
