postgresql/src/include/commands/extension.h

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/*-------------------------------------------------------------------------
*
* extension.h
* Extension management commands (create/drop extension).
*
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/commands/extension.h
*
*-------------------------------------------------------------------------
*/
#ifndef EXTENSION_H
#define EXTENSION_H
#include "catalog/objectaddress.h"
#include "parser/parse_node.h"
/*
Delete deleteWhatDependsOn() in favor of more performDeletion() flag bits. deleteWhatDependsOn() had grown an uncomfortably large number of assumptions about what it's used for. There are actually only two minor differences between what it does and what a regular performDeletion() call can do, so let's invent additional bits in performDeletion's existing flags argument that specify those behaviors, and get rid of deleteWhatDependsOn() as such. (We'd probably have done it this way from the start, except that performDeletion didn't originally have a flags argument, IIRC.) Also, add a SKIP_EXTENSIONS flag bit that prevents ever recursing to an extension, and use that when dropping temporary objects at session end. This provides a more general solution to the problem addressed in a hacky way in commit 08dd23cec: if an extension script creates temp objects and forgets to remove them again, the whole extension went away when its contained temp objects were deleted. The previous solution only covered temp relations, but this solves it for all object types. These changes require minor additions in dependency.c to pass the flags to subroutines that previously didn't get them, but it's still a net savings of code, and it seems cleaner than before. Having done this, revert the special-case code added in 08dd23cec that prevented addition of pg_depend records for temp table extension membership, because that caused its own oddities: dropping an extension that had created such a table didn't automatically remove the table, leading to a failure if the table had another dependency on the extension (such as use of an extension data type), or to a duplicate-name failure if you then tried to recreate the extension. But we keep the part that prevents the pg_temp_nnn schema from becoming an extension member; we never want that to happen. Add a regression test case covering these behaviors. Although this fixes some arguable bugs, we've heard few field complaints, and any such problems are easily worked around by explicitly dropping temp objects at the end of extension scripts (which seems like good practice anyway). So I won't risk a back-patch. Discussion: https://postgr.es/m/e51f4311-f483-4dd0-1ccc-abec3c405110@BlueTreble.com
2016-12-02 20:57:35 +01:00
* creating_extension is only true while running a CREATE EXTENSION or ALTER
* EXTENSION UPDATE command. It instructs recordDependencyOnCurrentExtension()
* to register a dependency on the current pg_extension object for each SQL
* object created by an extension script. It also instructs performDeletion()
* to remove such dependencies without following them, so that extension
* scripts can drop member objects without having to explicitly dissociate
* them from the extension first.
*/
Allow on-the-fly capture of DDL event details This feature lets user code inspect and take action on DDL events. Whenever a ddl_command_end event trigger is installed, DDL actions executed are saved to a list which can be inspected during execution of a function attached to ddl_command_end. The set-returning function pg_event_trigger_ddl_commands can be used to list actions so captured; it returns data about the type of command executed, as well as the affected object. This is sufficient for many uses of this feature. For the cases where it is not, we also provide a "command" column of a new pseudo-type pg_ddl_command, which is a pointer to a C structure that can be accessed by C code. The struct contains all the info necessary to completely inspect and even reconstruct the executed command. There is no actual deparse code here; that's expected to come later. What we have is enough infrastructure that the deparsing can be done in an external extension. The intention is that we will add some deparsing code in a later release, as an in-core extension. A new test module is included. It's probably insufficient as is, but it should be sufficient as a starting point for a more complete and future-proof approach. Authors: Álvaro Herrera, with some help from Andres Freund, Ian Barwick, Abhijit Menon-Sen. Reviews by Andres Freund, Robert Haas, Amit Kapila, Michael Paquier, Craig Ringer, David Steele. Additional input from Chris Browne, Dimitri Fontaine, Stephen Frost, Petr Jelínek, Tom Lane, Jim Nasby, Steven Singer, Pavel Stěhule. Based on original work by Dimitri Fontaine, though I didn't use his code. Discussion: https://www.postgresql.org/message-id/m2txrsdzxa.fsf@2ndQuadrant.fr https://www.postgresql.org/message-id/20131108153322.GU5809@eldon.alvh.no-ip.org https://www.postgresql.org/message-id/20150215044814.GL3391@alvh.no-ip.org
2015-05-12 00:14:31 +02:00
extern PGDLLIMPORT bool creating_extension;
extern PGDLLIMPORT Oid CurrentExtensionObject;
extern ObjectAddress CreateExtension(ParseState *pstate, CreateExtensionStmt *stmt);
extern void RemoveExtensionById(Oid extId);
extern ObjectAddress InsertExtensionTuple(const char *extName, Oid extOwner,
Oid schemaOid, bool relocatable, const char *extVersion,
Datum extConfig, Datum extCondition,
List *requiredExtensions);
extern ObjectAddress ExecAlterExtensionStmt(ParseState *pstate, AlterExtensionStmt *stmt);
extern ObjectAddress ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt,
ObjectAddress *objAddr);
extern Oid get_extension_oid(const char *extname, bool missing_ok);
extern char *get_extension_name(Oid ext_oid);
Invent "trusted" extensions, and remove the pg_pltemplate catalog. This patch creates a new extension property, "trusted". An extension that's marked that way in its control file can be installed by a non-superuser who has the CREATE privilege on the current database, even if the extension contains objects that normally would have to be created by a superuser. The objects within the extension will (by default) be owned by the bootstrap superuser, but the extension itself will be owned by the calling user. This allows replicating the old behavior around trusted procedural languages, without all the special-case logic in CREATE LANGUAGE. We have, however, chosen to loosen the rules slightly: formerly, only a database owner could take advantage of the special case that allowed installation of a trusted language, but now anyone who has CREATE privilege can do so. Having done that, we can delete the pg_pltemplate catalog, moving the knowledge it contained into the extension script files for the various PLs. This ends up being no change at all for the in-core PLs, but it is a large step forward for external PLs: they can now have the same ease of installation as core PLs do. The old "trusted PL" behavior was only available to PLs that had entries in pg_pltemplate, but now any extension can be marked trusted if appropriate. This also removes one of the stumbling blocks for our Python 2 -> 3 migration, since the association of "plpythonu" with Python 2 is no longer hard-wired into pg_pltemplate's initial contents. Exactly where we go from here on that front remains to be settled, but one problem is fixed. Patch by me, reviewed by Peter Eisentraut, Stephen Frost, and others. Discussion: https://postgr.es/m/5889.1566415762@sss.pgh.pa.us
2020-01-30 00:42:43 +01:00
extern bool extension_file_exists(const char *extensionName);
extern ObjectAddress AlterExtensionNamespace(const char *extensionName, const char *newschema,
Oid *oldschema);
#endif /* EXTENSION_H */