Add FDW documentation notes about insert and update tuple routing and COPY.

Author: Laurenz Albe and Etsuro Fujita
Reviewed-by: Laurenz Albe and Amit Langote
Backpatch-through: 11 where support for that by FDWs was added
Discussion: https://postgr.es/m/bf36a0288e8f31b4f2f40952e225bf892dc1ffc5[email protected]

diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml
index 2c07a866372c9ef629edec7d374f165bfcd541b6..eb92253e38792969ce82f4ecca28a8735c4d62a5 100644 (file)
--- a/doc/src/sgml/fdwhandler.sgml
+++ b/doc/src/sgml/fdwhandler.sgml
@@ -593,6 +593,14 @@ ExecForeignInsert(EState *estate,
      with an error message.
     
 
+    
+     Note that this function is also called when inserting routed tuples into
+     a foreign-table partition or executing COPY FROM on
+     a foreign table, in which case it is called in a different way than it
+     is in the INSERT case.  See the callback functions
+     described below that allow the FDW to support that.
+    
+
     
 
 TupleTableSlot *
@@ -751,6 +759,13 @@ BeginForeignInsert(ModifyTableState *mtstate,
      NULL, no action is taken for the initialization.
     
 
+    
+     Note that if the FDW does not support routable foreign-table partitions
+     and/or executing COPY FROM on foreign tables, this
+     function or ExecForeignInsert subsequently called
+     must throw error as needed.
+    
+
     
 
 void