https://github.com/ozum/pg_cache_tree
PostgreSQL trigger to cache recursive parents and children of a record in an array field.
https://github.com/ozum/pg_cache_tree
Last synced: about 2 months ago
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PostgreSQL trigger to cache recursive parents and children of a record in an array field.
- Host: GitHub
- URL: https://github.com/ozum/pg_cache_tree
- Owner: ozum
- License: mit
- Created: 2020-04-21T09:37:16.000Z (about 5 years ago)
- Default Branch: master
- Last Pushed: 2020-04-21T09:38:21.000Z (about 5 years ago)
- Last Synced: 2025-02-09T18:24:59.736Z (3 months ago)
- Language: PLpgSQL
- Size: 8.79 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# pg_cache_tree
## Abstract
PostgreSQL trigger to cache recursive parents and children of a record in an array field.
## Description
This is a PostgreSQL extension which adds a trigger, and related support and utility functions to store and update recursive parent-child list.
## Synopsis
On CLI:
$ make install
### Create Extension and Example Table
```SQL
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
);
```
### Option A: Add Single Trigger
```SQL
-- 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"}');
```
### Option B: Add Two Triggers
```SQL
-- 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"}');
```
### Option C: Add Two Triggers Using `ct_create_trigger()`
```SQL
-- Showign with default values
SELECT ct_create_trigger('public."BusinessUnit"', id => 'id', parent => 'parentId', parents => 'parentsCache', children => 'childrenCache');
```
```SQL
-- 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} | {} |
## What is included?
- `ct_trigger_update_cache()` trigger function
- `ct_create_trigger()`, `ct_drop_trigger()` utility functions
- Support functions and operators
## Install
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
## Dependencies
No dependencies.
## Copyright and License
See LICENSE file. Copyright (c) 2016 Özüm Eldoğan.