Hi fellows We use Calcite's materialization view in our product env, and it OOM times, I dig the memory dump and found there all of RelOptMaterialization instance.
We will call Planner#clear before every query, and inside the dump, there are lots of planner instance, soI suspect it is a circular reference that JVM can not gc them, here's the chain: 1. org.apache.calcite.plan.volcano.VolcanoPlanner#materializations: List<RelOptMaterialization> 2. org.apache.calcite.plan.RelOptMaterialization#queryRel: AbstractRelNode 3. org.apache.calcite.rel.AbstractRelNode#cluster: RelOptCluster 4. org.apache.calcite.plan.RelOptCluster#planner: VolcanoPlanner 5. org.apache.calcite.plan.volcano.VolcanoPlanner#materializations: List<RelOptMaterialization> Regards! Aron Tao
