fix: correct hybrid_search function to match official Supabase docs

- Use <#> (inner product) operator instead of <=> (cosine distance)
- Use extensions.vector(512) instead of vector(1536)
- Remove `stable` and `security invoker` qualifiers
- Add full_text_weight, semantic_weight, rrf_k parameters
- Use least(match_count, 30) cap for over-fetching
- Remove default value from match_count (required param)
- Use parameterized rrf_k and weights in RRF scoring formula

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Pedro Rodrigues
2026-02-09 15:59:45 +00:00
parent f4d228d448
commit 6c1b7af187

View File

@@ -42,7 +42,7 @@ Fetching exact match_count from each source may miss relevant results after fusi
```sql
-- May miss good results after RRF fusion
with semantic as (select id from docs order by embedding <=> query limit 5),
with semantic as (select id from docs order by embedding <#> query limit 5),
full_text as (select id from docs where fts @@ query limit 5)
select * from semantic union full_text limit 5;
```
@@ -50,38 +50,44 @@ select * from semantic union full_text limit 5;
**Correct:**
```sql
-- Fetch 2x from each, then fuse and limit
with semantic as (select id from docs order by embedding <=> query limit 10),
full_text as (select id from docs where fts @@ query limit 10)
-- Over-fetch 2x with least() cap, then fuse and limit
with semantic as (select id from docs order by embedding <#> query limit least(5, 30) * 2),
full_text as (select id from docs where fts @@ query limit least(5, 30) * 2)
-- Apply RRF scoring...
limit 5;
limit least(5, 30);
```
## Complete Hybrid Search Function
```sql
create function hybrid_search(
create or replace function hybrid_search(
query_text text,
query_embedding vector(1536),
match_count int default 10
query_embedding extensions.vector(512),
match_count int,
full_text_weight float = 1,
semantic_weight float = 1,
rrf_k int = 50
)
returns setof documents language sql stable security invoker as $$
returns setof documents language sql as $$
with full_text as (
select id, row_number() over (order by ts_rank_cd(fts, websearch_to_tsquery(query_text)) desc) as rank_ix
from documents where fts @@ websearch_to_tsquery(query_text)
limit match_count * 2
limit least(match_count, 30) * 2
),
semantic as (
select id, row_number() over (order by embedding <=> query_embedding) as rank_ix
select id, row_number() over (order by embedding <#> query_embedding) as rank_ix
from documents
order by embedding <=> query_embedding
limit match_count * 2
order by embedding <#> query_embedding
limit least(match_count, 30) * 2
)
select documents.* from full_text
full outer join semantic on full_text.id = semantic.id
join documents on coalesce(full_text.id, semantic.id) = documents.id
order by coalesce(1.0/(50+full_text.rank_ix),0) + coalesce(1.0/(50+semantic.rank_ix),0) desc
limit match_count;
order by
coalesce(1.0/(rrf_k + full_text.rank_ix), 0.0) * full_text_weight +
coalesce(1.0/(rrf_k + semantic.rank_ix), 0.0) * semantic_weight
desc
limit least(match_count, 30);
$$;
```