SELECT * FROM pg_vector_index_stat does not work with partitions

[ydylla]

Hi,
I noticed that SELECT * FROM pg_vector_index_stat does not work when an index for a partitioned table was created. It produces the following error: [XX000] ERROR: pgvecto.rs: The index is not existing in the background worker..

Here is a reproducer for Postgres 15 and pgvecto.rs 0.2.1 based on the existing partition.slt:

CREATE TABLE items (val vector(3), category_id int) PARTITION BY LIST(category_id);

CREATE TABLE id_123 PARTITION OF items FOR VALUES IN (1, 2, 3);
CREATE TABLE id_456 PARTITION OF items FOR VALUES IN (4, 5, 6);

INSERT INTO items (val, category_id)
SELECT
    ARRAY[random(), random(), random()]::real[],
    (random() * 5 + 1)::int
FROM generate_series(1, 1000);

CREATE INDEX ON items USING vectors (val vector_l2_ops);

SELECT * FROM pg_vector_index_stat; -- fails
SELECT * FROM pg_vector_index_stat WHERE indexname = 'items_val_idx'; -- fails
SELECT * FROM pg_vector_index_stat WHERE indexname = 'id_123_val_idx'; -- works

[usamoi]

It'll be fixed in next version and you could use

CREATE OR REPLACE VIEW pg_vector_index_stat AS
    SELECT
        C.oid AS tablerelid,
        I.oid AS indexrelid,
        C.relname AS tablename,
        I.relname AS indexname,
        (_vectors_index_stat(I.oid)).*
    FROM pg_class C JOIN
         pg_index X ON C.oid = X.indrelid JOIN
         pg_class I ON I.oid = X.indexrelid JOIN
         pg_am A ON A.oid = I.relam
    WHERE A.amname = 'vectors' AND C.relkind = 'r';

to fix the behavior in current version.

[ydylla]

Thanks for the quick reply @usamoi.
I tried your workaround but now I get a different error [XX000] ERROR: oid_ is null and even the query that previously did work now no longer works. Somehow I bricked it 😅 since even going back to the view without the AND C.relkind = 'r' fix is now broken. I guess I have to reinstall the extension, luckily it's just a test setup.

[usamoi]

Thanks for the quick reply @usamoi. I tried your workaround but now I get a different error [XX000] ERROR: oid_ is null and even the query that previously did work now no longer works. Somehow I bricked it 😅 since even going back to the view without the AND C.relkind = 'r' fix is now broken. I guess I have to reinstall the extension, luckily it's just a test setup.

Feel sorry for it. I forgot that the view is changed in development branch since v0.2.1.

If you are using v0.2.1,

CREATE OR REPLACE VIEW pg_vector_index_stat AS
    SELECT
        C.oid AS tablerelid,
        I.oid AS indexrelid,
        C.relname AS tablename,
        I.relname AS indexname,
        (_vectors_index_stat(I.relfilenode)).*
    FROM pg_class C JOIN
         pg_index X ON C.oid = X.indrelid JOIN
         pg_class I ON I.oid = X.indexrelid JOIN
         pg_am A ON A.oid = I.relam
    WHERE A.amname = 'vectors' AND C.relkind = 'r';

should work.

[ydylla]

It still produces the same error. But don't worry I will just reinstall the extension.