- [ ] DistPartitionKey()
   - [x] Add DistPartitionKeys
   - [ ] Remove DistPartitionKey
- [ ] DistPartitionKeyOrError()
   - [ ] Add DistPartitionKeysOrError
   - [ ] Remove DistPartitionKeyOrError
- [ ] PartitionColumn()
   - [x] Add PartitionColumns
   - [ ] Remove PartitionColumn
- [ ] IsPartitionColumn()
- [ ] PartitionColumnIndex(Var *targetVar, List *targetList)
- [ ] PartitionColumnIndex(List *insertTargetList, Var *partitionColumn);
- [ ] PartitionColumnIndexFromColumnList()
- [ ] PartitionedOnColumn()
- [ ] GroupedByPartitionColumn()
- [ ] HasNonPartitionColumnDistinctAgg()
- [ ] PruneShards()
- [ ] PartitionColumnInTableList()
- [ ] MakeJoinOrderNode()
- [ ] CheckPartitionColumn()
- [ ] InsertPartitionColumnMatchesSelect()
- [ ] PartitionColumnIndexOrPartitionColumnName()
- [ ] CreateDistributedTableLike()
- [x] EnsureRelationCanBeDistributed()
- [ ] ErrorIfUnsupportedConstraint()
- [ ] ColocationIdForNewTable()
- [ ] InsertMetadataForCitusLocalTable()
- [ ] CreateDistributedTableLike()
- [x] BuildCitusTableCacheEntry()
- [ ] PostprocessCreateTableStmtPartitionOf()
- [ ] PostprocessAlterTableStmtAttachPartition()
- [x] TargetListOnPartitionColumn()
- [ ] PartitionColumnForPushedDownSubquery()
- [ ] CoPartitionedTables()
- [x] LocalJoin()
- [ ] SinglePartitionJoin()
- [ ] ApplySinglePartitionJoin()
- [ ] MultiJoinTree()

# query pushdown planner
- [x] RestrictionEquivalenceForPartitionKeys()
- [x] EquivalenceListContainsRelationsEquality()
- [ ] SafeToPushdownUnionSubquery()
- [ ] RelationRestrictionPartitionKeyIndex()


- [ ] PartitionMethod()

- [ ] better range distribution support
- [ ] list distribution support