Coral can be used to not just convert the queries between the popular query engines like spark, hive and trino can be used get the optimized plans by applying all latest Rules implemented in calcite as well as make use of rewrite capabilities supported by calcite using materialized views etc. Current version does have very limited support of materialized view rewrite capabilities because of missing rules like these https://github.com/apache/calcite/blob/main/core/src/main/java/org/apache/calcite/rel/rules/CoreRules.java.