diff --git a/README.md b/README.md index 9b8103f..491c241 100644 --- a/README.md +++ b/README.md @@ -223,21 +223,27 @@ The phases are: Note: `tuples_done` and `tuples_total` are only populated during the `loading tuples` phase -### Partial Indexes +### Filtering -Consider [partial indexes](https://www.postgresql.org/docs/current/indexes-partial.html) for queries with a `WHERE` clause +There are a few ways to index nearest neighbor queries with a `WHERE` clause ```sql SELECT * FROM items WHERE category_id = 123 ORDER BY embedding <-> '[3,1,2]' LIMIT 5; ``` -can be indexed with: +Create an index on one or more of the `WHERE` columns for exact search + +```sql +CREATE INDEX ON items (category_id); +``` + +Or a [partial index](https://www.postgresql.org/docs/current/indexes-partial.html) on the vector column for approximate search ```sql CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WITH (lists = 100) WHERE (category_id = 123); ``` -To index many different values of `category_id`, consider [partitioning](https://www.postgresql.org/docs/current/ddl-partitioning.html) on `category_id`. +Use [partitioning](https://www.postgresql.org/docs/current/ddl-partitioning.html) for approximate search on many different values of the `WHERE` columns ```sql CREATE TABLE items (embedding vector(3), category_id int) PARTITION BY LIST(category_id);