RUM documentation

apps/docs/data/extensions.json

@@ -482,4 +482,11 @@
     "installed_version": null,
     "comment": "XPath querying and XSLT"
   }
+  {
+    "name": "rum",
+    "schema": "extensions",
+    "default_version": "1.3.13",
+    "installed_version": "1.3.13",
+    "comment": "GIN-like index for text search"
+  }
 ]

apps/docs/pages/guides/database/extensions/rum.mdx

@@ -0,0 +1,162 @@
+import Layout from '~/layouts/DefaultGuideLayout'
+
+export const meta = {
+  id: 'rum',
+  title: 'RUM: improved inverted index for full-text search based on GIN index',
+  description: 'A GIN-like index with additional tree-organized data for each index entry',
+}
+
+[RUM](https://github.com/postgrespro/rum) is an extension which adds a RUM index to Postgresql.
+
+RUM index is based on GIN that stores additional per-entry information in a posting tree. For example, positional information of lexemes or timestamps. In comparison to GIN it can use this information to make faster index-only scans for:
+
+- Phrase search
+- Text search with ranking by text distance operator
+- Text `SELECT`s with ordering by some non-indexed additional column e.g. by timestamp.
+
+RUM works best in scenarios when the possible keys are highly repeatable. I.e. all texts are composed of a
+limited amount of words, so per-lexeme indexing gives significant speed-up in searching texts containing word
+combinations or phrases.
+
+Main operators for ordering are:
+
+tsvector <=> tsquery	| float4	| Distance between tsvector and tsquery.
+value <=> value			| float8	| Distance between two values.
+
+Where value is timestamp, timestamptz, int2, int4, int8, float4, float8, money and oid
+
+## Usage
+
+### Enable the extension
+
+You can get started with rum by enabling the extension in your Supabase dashboard.
+
+<Tabs
+  scrollable
+  size="small"
+  type="underlined"
+  defaultActiveId="dashboard"
+>
+<TabPanel id="dashboard" label="Dashboard">
+
+1. Go to the [Database](https://app.supabase.com/project/_/database/tables) page in the Dashboard.
+2. Click on **Extensions** in the sidebar.
+3. Search for "rum" and enable the extension.
+
+</TabPanel>
+<TabPanel id="sql" label="SQL">
+
+```sql
+-- Example: enable the "rum" extension
+create extension rum with schema extensions;
+
+-- Example: disable the "rum" extension
+drop extension if exists rum;
+```
+
+</TabPanel>
+</Tabs>
+
+### Syntax
+
+####For type: tsvector
+
+To understand the following you may need first to see [Official PostgreSQL documentation on text
+search](https://www.postgresql.org/docs/current/functions-textsearch.html)
+
+`rum_tsvector_ops`
+
+```sql
+CREATE TABLE test_rum(t text, a tsvector);
+
+CREATE TRIGGER tsvectorupdate
+BEFORE UPDATE OR INSERT ON test_rum
+FOR EACH ROW EXECUTE PROCEDURE tsvector_update_trigger('a', 'pg_catalog.english', 't');
+
+INSERT INTO test_rum(t) VALUES ('The situation is most beautiful');
+INSERT INTO test_rum(t) VALUES ('It is a beautiful');
+INSERT INTO test_rum(t) VALUES ('It looks like a beautiful place');
+
+CREATE INDEX rumidx ON test_rum USING rum (a rum_tsvector_ops);
+```
+
+And we can execute `tsvector` selects with ordering by text distance operator:
+
+```sql
+SELECT t, a <=> to_tsquery('english', 'beautiful | place') AS rank
+    FROM test_rum
+    WHERE a @@ to_tsquery('english', 'beautiful | place')
+    ORDER BY a <=> to_tsquery('english', 'beautiful | place');
+                t                |  rank
+---------------------------------+---------
+ It looks like a beautiful place | 8.22467
+ The situation is most beautiful | 16.4493
+ It is a beautiful               | 16.4493
+(3 rows)
+```
+
+`rum_tsvector_addon_ops`
+
+```sql
+CREATE TABLE tsts (id int, t tsvector, d timestamp);
+CREATE INDEX tsts_idx ON tsts USING rum (t rum_tsvector_addon_ops, d)
+    WITH (attach = 'd', to = 't');
+```
+
+Now we can execute the selects with ordering distance operator on attached column:
+
+```sql
+SELECT id, d, d <=> '2016-05-16 14:21:25' FROM tsts WHERE t @@ 'wr&qh' ORDER BY d <=> '2016-05-16 14:21:25' LIMIT 5;
+ id  |                d                |   ?column?
+-----+---------------------------------+---------------
+ 355 | Mon May 16 14:21:22.326724 2016 |      2.673276
+ 354 | Mon May 16 13:21:22.326724 2016 |   3602.673276
+ 371 | Tue May 17 06:21:22.326724 2016 |  57597.326724
+ 406 | Wed May 18 17:21:22.326724 2016 | 183597.326724
+ 415 | Thu May 19 02:21:22.326724 2016 | 215997.326724
+(5 rows)
+```
+
+####For type: anyarray
+
+`rum_anyarray_ops`
+
+This operator class stores anyarray elements with length of the array. It supports operators &&, @>, <@, =, % operators. It also supports ordering by <=> operator.
+
+```sql
+CREATE TABLE test_array (i int2[]);
+INSERT INTO test_array VALUES ('{}'), ('{0}'), ('{1,2,3,4}'), ('{1,2,3}'), ('{1,2}'), ('{1}');
+CREATE INDEX idx_array ON test_array USING rum (i rum_anyarray_ops);
+```
+
+Now we can execute the query using index scan:
+```sql
+SELECT * FROM test_array WHERE i && '{1}' ORDER BY i <=> '{1}' ASC;
+     i
+-----------
+ {1}
+ {1,2}
+ {1,2,3}
+ {1,2,3,4}
+(4 rows)
+```
+
+`rum_anyarray_addon_ops`
+
+The does the same with anyarray index as `rum_tsvector_addon_ops` i.e. allows to order select results using distance
+operator by attached column.
+
+
+## Limitations
+
+`RUM` has slower build and insert times than `GIN` due to:
+1. It is bigger than due to the additional attributes stored in the index.
+2. It uses generic WAL records.
+
+## Resources
+
+- [Official RUM documentation](https://github.com/postgrespro/rum)
+
+export const Page = ({ children }) => <Layout meta={meta} children={children} />
+
+export default Page