Hi,
Following ALTER TABLE actions are applied recursively to inheritance
descendents via ATSimpleRecursion() -
ALTER COLUMN DEFAULT
ALTER COLUMN DROP NOT NULL
ALTER COLUMN SET NOT NULL
ALTER COLUMN SET STATISTICS
ALTER COLUMN SET STORAGE
The code at the beginning of ATSimpleRecursion() looks like -
/** Propagate to children if desired. Non-table relations never have* children, so no need to search in that case.*/if
(recurse&& rel->rd_rel->relkind == RELKIND_RELATION)
Not sure if it's great idea, but now that foreign tables can also have
children, should above be changed to take that into account? Any inheritance
related recursion performed without using ATSimpleRecursion() recurse as
dictated by RangeVar.inhOpt; so even foreign inheritance parents expand for
various ALTER TABLE actions like adding a column though that is not a
meaningful operation on foreign tables anyway.
An example,
postgres=# alter foreign table fparent alter a type char;
ALTER FOREIGN TABLE
postgres=# select * from fparent;
ERROR: attribute "a" of relation "fchild1" does not match parent's type
Above error, AIUI, is hit much before it is determined that fparent is a
foreign table, whereas the following is FDW-specific (waiting to happen) error,
postgres=# alter foreign table fparent add b char;
ALTER FOREIGN TABLE
postgres=# SELECT * FROM fparent;
ERROR: column "b" does not exist
CONTEXT: Remote SQL command: SELECT a, b FROM public.parent
Not sure if the first case could be considered s a bug as foreign tables are
pretty lax in these regards anyway. But if ATSimpleRecursion() prevents errors
that result from concepts independent of foreign tables being involved, maybe,
we need to fix?
Thanks,
Amit
