Generalize ri_RootToPartitionMap to use for non-partition children

ri_RootToPartitionMap is currently only initialized for tuple routing
target partitions, though a future commit will need the ability to use
it even for the non-partition child tables, so make adjustments to the
decouple it from the partitioning code.

Also, make it lazily initialized via ExecGetRootToChildMap(), making
that function its preferred access path.  Existing third-party code
accessing it directly should no longer do so; consequently, it's been
renamed to ri_RootToChildMap, which also makes it consistent with
ri_ChildToRootMap.

ExecGetRootToChildMap() houses the logic of setting the map appropriately
depending on whether a given child relation is partition or not.

To support this, also add a separate entry point for TupleConversionMap
creation that receives an AttrMap.  No new code here, just split an
existing function in two.

Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CA+HiwqEYUhDXSK5BTvG_xk=eaAEJCD4GS3C6uH7ybBvv+Z_Tmg@mail.gmail.com

1 files changed, 1 insertions, 0 deletions

diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index ed95ed1176d..aaf2bc78b9c 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -600,6 +600,7 @@ extern TupleTableSlot *ExecGetTriggerOldSlot(EState *estate, ResultRelInfo *relI
 extern TupleTableSlot *ExecGetTriggerNewSlot(EState *estate, ResultRelInfo *relInfo);
 extern TupleTableSlot *ExecGetReturningSlot(EState *estate, ResultRelInfo *relInfo);
 extern TupleConversionMap *ExecGetChildToRootMap(ResultRelInfo *resultRelInfo);
+extern TupleConversionMap *ExecGetRootToChildMap(ResultRelInfo *resultRelInfo, EState *estate);
 
 extern Bitmapset *ExecGetInsertedCols(ResultRelInfo *relinfo, EState *estate);
 extern Bitmapset *ExecGetUpdatedCols(ResultRelInfo *relinfo, EState *estate);