In the spirit of 890192e99a and 4464303405f: have get_object_address
understand individual pg_amop and pg_amproc objects. There is no way to
refer to such objects directly in the grammar -- rather, they are almost
always considered an integral part of the opfamily that contains them.
(The only case that deals with them individually is ALTER OPERATOR
FAMILY ADD/DROP, which carries the opfamily address separately and thus
does not need it to be part of each added/dropped element's address.)
In event triggers it becomes possible to become involved with individual
amop/amproc elements, and this commit enables pg_get_object_address to
do so as well.
To make the overall coding simpler, this commit also slightly changes
the get_object_address representation for opclasses and opfamilies:
instead of having the AM name in the objargs array, I moved it as the
first element of the objnames array. This enables the new code to use
objargs for the type names used by pg_amop and pg_amproc.
Reviewed by: Stephen Frost
In the spirit of 890192e99a, this time add support for the things
living in the pg_default_acl catalog. These are not really "objects",
but they show up as such in event triggers.
There is no "DROP DEFAULT PRIVILEGES" or similar command, so it doesn't
look like the new representation given would be useful anywhere else, so
I didn't try to use it outside objectaddress.c. (That might be a bug in
itself, but that would be material for another commit.)
Reviewed by Stephen Frost.
Since commit 72dd233d3e we were trying to obtain object addressing
information in sql_drop event triggers, but that caused failures when
the drops involved user mappings. This addition enables that to work
again. Naturally, pg_get_object_address can work with these objects
now, too.
I toyed with the idea of removing DropUserMappingStmt as a node and
using DropStmt instead in the DropUserMappingStmt grammar production,
but that didn't go very well: for one thing the messages thrown by the
specific code are specialized (you get "server not found" if you specify
the wrong server, instead of a generic "user mapping for ... not found"
which you'd get it we were to merge this with RemoveObjects --- unless
we added even more special cases). For another thing, it would require
to pass RoleSpec nodes through the objname/objargs representation used
by RemoveObjects, which works in isolation, but gets messy when
pg_get_object_address is involved. So I dropped this part for now.
Reviewed by Stephen Frost.
The original representation uses "opcname for amname", which is good
enough; but if we replace "for" with "using", we can apply the returned
identity directly in a DROP command, as in
DROP OPERATOR CLASS opcname USING amname
This slightly simplifies code using object identities to programatically
execute commands on these kinds of objects.
Note backwards-incompatible change:
The previous representation dates back to 9.3 when object identities
were introduced by commit f8348ea3, but we don't want to change the
behavior on released branches unnecessarily and so this is not
backpatched.
This function returns object type and objname/objargs arrays, which can
be passed to pg_get_object_address. This is especially useful because
the textual representation can be copied to a remote server in order to
obtain the corresponding OID-based address. In essence, this function
is the inverse of recently added pg_get_object_address().
Catalog version bumped due to the addition of the new function.
Also add docs to pg_get_object_address.
It is causing trouble when run in parallel mode, because dropping the
function other sessions are running concurrently causes them to fail due
to inability to find the function.
Per buildfarm, as noted by Tom Lane.
This allows access to get_object_address from SQL, which is useful to
obtain OID addressing information from data equivalent to that emitted
by the parser. This is necessary infrastructure of a project to let
replication systems propagate object dropping events to remote servers,
where the schema might be different than the server originating the
DROP.
This patch also adds support for OBJECT_DEFAULT to get_object_address;
that is, it is now possible to refer to a column's default value.
Catalog version bumped due to the new function.
Reviewed by Stephen Frost, Heikki Linnakangas, Robert Haas, Andres
Freund, Abhijit Menon-Sen, Adam Brightwell.
Peter Eisentraut
Alvaro Herrera
Tom Lane