CREATE UNIQUE INDEX IF NOT EXISTS ux_items_ns_key
  ON memory_items(namespace_id, key)
  WHERE key IS NOT NULL;

CREATE INDEX IF NOT EXISTS ix_chunks_item ON memory_chunks(item_id);

CREATE INDEX IF NOT EXISTS idx_chunks_content_tsv
  ON memory_chunks USING GIN(content_tsv);

CREATE INDEX IF NOT EXISTS ix_embed_model_dim ON embeddings(model, dim);

-- per-model ANN index (duplicate with each concrete model name)
CREATE INDEX IF NOT EXISTS ix_embed_vec_model_default
  ON embeddings USING ivfflat (vector vector_cosine_ops)
  WHERE model = 'default-emb';