PostgreSQL trigger to cache recursive parents and children of a record in an array field.
This is a PostgreSQL extension which adds a trigger, and related support and utility functions to store and update recursive parent-child list.
On CLI:
$ make install
CREATE EXTENSION pg_cache_tree;
CREATE TABLE "BusinessUnit" (
id INTEGER NOT NULL,
"parentId" INTEGER,
"parentsCache" INTEGER [] DEFAULT '{}'::integer[] NOT NULL,
"childrenCache" INTEGER [] DEFAULT '{}'::integer[] NOT NULL,
CONSTRAINT "BusinessUnit_PK" PRIMARY KEY(id),
CONSTRAINT "BusinessUnit_Parent_FK" FOREIGN KEY ("parentId")
REFERENCES "BusinessUnit"(id)
ON DELETE CASCADE
ON UPDATE CASCADE
);
-- Showign with default values
CREATE TRIGGER "parentId_trigger" AFTER INSERT OR DELETE OR UPDATE OF "id", "parentId" ON "BusinessUnit"
FOR EACH ROW EXECUTE PROCEDURE ct_trigger_update_cache('{"id": "id", "parent": "parentId", "parents": "parentsCache", "children": "childrenCache"}');
-- Showign with default values
CREATE TRIGGER "parentId_insert_delete_trigger" AFTER INSERT OR DELETE ON "BusinessUnit"
FOR EACH ROW EXECUTE PROCEDURE
ct_trigger_update_cache('{"id": "id", "parent": "parentId", "parents": "parentsCache", "children": "childrenCache"}');
CREATE TRIGGER "parentId_update_trigger" AFTER UPDATE OF "id", "parentId" ON "BusinessUnit"
FOR EACH ROW WHEN (old.id IS DISTINCT FROM new.id OR old."parentId" IS DISTINCT FROM new."parentId") EXECUTE PROCEDURE
ct_trigger_update_cache('{"id": "id", "parent": "parentId", "parents": "parentsCache", "children": "childrenCache"}');
-- Showign with default values
SELECT ct_create_trigger('public."BusinessUnit"', id => 'id', parent => 'parentId', parents => 'parentsCache', children => 'childrenCache');
-- Insert some values. Triggers update parents and children cache.
INSERT INTO "BusinessUnit" ("id", "parentId") VALUES
(1, NULL),
(2, 1),
(20, 2),
(21, 2);
SELECT * FROM "BusinessUnit";
id | parentId | parentsCache | childrenCache |
---|---|---|---|
1 | null | {} | {2,21,20} |
2 | 1 | {1} | {21,20} |
20 | 2 | {1,2} | {} |
21 | 2 | {1,2} | {} |
ct_trigger_update_cache()
trigger functionct_create_trigger()
,ct_drop_trigger()
utility functions- Support functions and operators
To build it, just do this:
make
make installcheck
make install
If you encounter an error such as:
"Makefile", line 8: Need an operator
You need to use GNU make, which may well be installed on your system as
gmake
:
gmake
gmake install
gmake installcheck
If you encounter an error such as:
make: pg_config: Command not found
Be sure that you have pg_config
installed and in your path. If you used a
package management system such as RPM to install PostgreSQL, be sure that the
-devel
package is also installed. If necessary tell the build process where
to find it:
env PG_CONFIG=/path/to/pg_config make && make installcheck && make install
And finally, if all that fails (and if you're on PostgreSQL 8.1 or lower, it
likely will), copy the entire distribution directory to the contrib/
subdirectory of the PostgreSQL source tree and try it there without
pg_config
:
env NO_PGXS=1 make && make installcheck && make install
If you encounter an error such as:
ERROR: must be owner of database regression
You need to run the test suite using a super user, such as the default "postgres" super user:
make installcheck PGUSER=postgres
Once pg_cache_tree is installed, you can add it to a database. If you're running PostgreSQL 9.1.0 or greater, it's a simple as connecting to a database as a super user and running:
CREATE EXTENSION pg_cache_tree;
If you've upgraded your cluster to PostgreSQL 9.1 and already had pg_cache_tree installed, you can upgrade it to a properly packaged extension with:
CREATE EXTENSION pg_cache_tree FROM unpackaged;
For versions of PostgreSQL less than 9.1.0, you'll need to run the installation script:
psql -d mydb -f /path/to/pgsql/share/contrib/pg_cache_tree.sql
If you want to install pg_cache_tree and all of its supporting objects into a specific
schema, use the PGOPTIONS
environment variable to specify the schema, like
so:
PGOPTIONS=--search_path=extensions psql -d mydb -f pg_cache_tree.sql
No dependencies.
See LICENSE file. Copyright (c) 2016 Özüm Eldoğan.