fix(db): respect vector extension config in per-bank index migration (#832)

* fix(db): respect vector extension config in per-bank index migration

Migration d5e6f7a8b9c0 hardcoded HNSW when creating per-bank partial
vector indexes, ignoring HINDSIGHT_API_VECTOR_EXTENSION. This caused
banks migrated from pre-v0.4.18 to get HNSW indexes even when
pgvectorscale (DiskANN) or vchord was configured.

- Fix the original migration to read the vector extension config
- Add migration a4b5c6d7e8f9 to detect and recreate mismatched indexes
  (skipped entirely when extension is pgvector, since those are correct)

* chore: regenerate openapi.json for v0.4.22 version bump

hindsight-api-slim/hindsight_api/alembic/versions/a4b5c6d7e8f9_fix_per_bank_vector_index_type.py

@@ -0,0 +1,142 @@
+"""Fix per-bank vector indexes to match configured extension
+
+Revision ID: a4b5c6d7e8f9
+Revises: c2d3e4f5g6h7, c5d6e7f8a9b0
+Create Date: 2026-04-01
+
+Migration d5e6f7a8b9c0 hardcoded HNSW when creating per-bank partial vector
+indexes, ignoring HINDSIGHT_API_VECTOR_EXTENSION. Banks that existed when that
+migration ran got HNSW indexes even when pgvectorscale (DiskANN) or vchord
+was configured.
+
+This migration detects the mismatch and recreates the affected indexes with
+the correct type. Skipped entirely when the configured extension is pgvector
+(the default), since those indexes are already correct.
+"""
+
+import os
+from collections.abc import Sequence
+
+from alembic import context, op
+from sqlalchemy import text
+
+revision: str = "a4b5c6d7e8f9"
+down_revision: str | Sequence[str] | None = "d6e7f8a9b0c1"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+_FACT_TYPES: dict[str, str] = {
+    "world": "worl",
+    "experience": "expr",
+    "observation": "obsv",
+}
+
+
+def _get_schema_prefix() -> str:
+    schema = context.config.get_main_option("target_schema")
+    return f'"{schema}".' if schema else ""
+
+
+def _target_index_type() -> str | None:
+    """Return the target index type, or None if pgvector (no fix needed)."""
+    ext = os.getenv("HINDSIGHT_API_VECTOR_EXTENSION", "pgvector").lower()
+    if ext == "pgvectorscale":
+        return "diskann"
+    elif ext == "vchord":
+        return "vchordrq"
+    return None
+
+
+def _vector_index_using_clause() -> str:
+    """Return the USING clause based on the configured vector extension."""
+    ext = os.getenv("HINDSIGHT_API_VECTOR_EXTENSION", "pgvector").lower()
+    if ext == "pgvectorscale":
+        return "USING diskann (embedding vector_cosine_ops) WITH (num_neighbors = 50)"
+    elif ext == "vchord":
+        return "USING vchordrq (embedding vector_l2_ops)"
+    else:
+        return "USING hnsw (embedding vector_cosine_ops)"
+
+
+def upgrade() -> None:
+    target = _target_index_type()
+    if target is None:
+        # pgvector — indexes are already HNSW, nothing to fix
+        return
+
+    bind = op.get_bind()
+    schema_name = context.config.get_main_option("target_schema")
+    schema = _get_schema_prefix()
+    table_ref = f'"{schema_name}".memory_units' if schema_name else "memory_units"
+    banks_ref = f'"{schema_name}".banks' if schema_name else "banks"
+    using_clause = _vector_index_using_clause()
+    pg_schema = schema_name or "public"
+
+    rows = bind.execute(text(f"SELECT bank_id, internal_id FROM {banks_ref}")).fetchall()  # noqa: S608
+    for row in rows:
+        bank_id = row[0]
+        internal_id = str(row[1]).replace("-", "")[:16]
+        escaped_bank_id = bank_id.replace("'", "''")
+        for ft, ft_short in _FACT_TYPES.items():
+            idx_name = f"idx_mu_emb_{ft_short}_{internal_id}"
+
+            # Check if this index exists and what type it is
+            idx_info = bind.execute(
+                text("SELECT indexdef FROM pg_indexes WHERE schemaname = :schema AND indexname = :idx"),
+                {"schema": pg_schema, "idx": idx_name},
+            ).fetchone()
+
+            if idx_info is None:
+                # Index doesn't exist — create it with the correct type
+                bind.execute(
+                    text(
+                        f"CREATE INDEX IF NOT EXISTS {idx_name} "
+                        f"ON {table_ref} {using_clause} "
+                        f"WHERE fact_type = '{ft}' AND bank_id = '{escaped_bank_id}'"
+                    )
+                )
+                continue
+
+            indexdef = idx_info[0].lower()
+            if target in indexdef:
+                # Already the correct type
+                continue
+
+            # Wrong type — drop and recreate
+            bind.execute(text(f"DROP INDEX IF EXISTS {schema}{idx_name}"))
+            bind.execute(
+                text(
+                    f"CREATE INDEX IF NOT EXISTS {idx_name} "
+                    f"ON {table_ref} {using_clause} "
+                    f"WHERE fact_type = '{ft}' AND bank_id = '{escaped_bank_id}'"
+                )
+            )
+
+
+def downgrade() -> None:
+    # Downgrade recreates indexes as HNSW (the original hardcoded behavior)
+    target = _target_index_type()
+    if target is None:
+        return
+
+    bind = op.get_bind()
+    schema_name = context.config.get_main_option("target_schema")
+    schema = _get_schema_prefix()
+    table_ref = f'"{schema_name}".memory_units' if schema_name else "memory_units"
+    banks_ref = f'"{schema_name}".banks' if schema_name else "banks"
+
+    rows = bind.execute(text(f"SELECT bank_id, internal_id FROM {banks_ref}")).fetchall()  # noqa: S608
+    for row in rows:
+        bank_id = row[0]
+        internal_id = str(row[1]).replace("-", "")[:16]
+        escaped_bank_id = bank_id.replace("'", "''")
+        for ft, ft_short in _FACT_TYPES.items():
+            idx_name = f"idx_mu_emb_{ft_short}_{internal_id}"
+            bind.execute(text(f"DROP INDEX IF EXISTS {schema}{idx_name}"))
+            bind.execute(
+                text(
+                    f"CREATE INDEX IF NOT EXISTS {idx_name} "
+                    f"ON {table_ref} USING hnsw (embedding vector_cosine_ops) "
+                    f"WHERE fact_type = '{ft}' AND bank_id = '{escaped_bank_id}'"
+                )
+            )

hindsight-api-slim/hindsight_api/alembic/versions/d5e6f7a8b9c0_add_bank_internal_id_and_per_bank_hnsw.py

@@ -1,4 +1,4 @@
-"""Add internal_id to banks and per-(bank, fact_type) partial HNSW indexes
+"""Add internal_id to banks and per-(bank, fact_type) partial vector indexes
 
 Revision ID: d5e6f7a8b9c0
 Revises: a3b4c5d6e7f8
@@ -6,25 +6,20 @@ Create Date: 2026-03-11
 
 This migration:
 1. Adds internal_id UUID column to banks (stable identifier for index naming)
-2. Drops the global HNSW index (competes with per-bank partial indexes)
+2. Drops the global vector index (competes with per-bank partial indexes)
-3. Creates per-(bank_id, fact_type) partial HNSW indexes for all existing banks
+3. Creates per-(bank_id, fact_type) partial vector indexes for all existing banks
-   (new banks get indexes created at bank-creation time via bank_utils.create_bank_hnsw_indexes)
+   using the configured vector extension (HNSW for pgvector, DiskANN for
+   pgvectorscale, vchordrq for vchord).
+   (new banks get indexes created at bank-creation time via bank_utils.create_bank_vector_indexes)
 
 Why per-(bank, fact_type) indexes:
 - fact_type-only partial indexes are never chosen by the planner when bank_id is in the WHERE
   clause, because the idx_memory_units_bank_id B-tree index always wins at planning time.
 - Per-(bank, fact_type) partial indexes have both predicates matching → planner selects them.
-- The global HNSW index competes for larger partitions (world, observation) and must be dropped.
+- The global vector index competes for larger partitions (world, observation) and must be dropped.
-
-For large deployments, create indexes CONCURRENTLY before running this migration:
-    SELECT internal_id, bank_id FROM banks;
-    -- for each bank and each fact_type in (world, experience, observation):
-    CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_mu_emb_{ft}_{uid16}
-        ON memory_units USING hnsw (embedding vector_cosine_ops)
-        WHERE fact_type = '{ft}' AND bank_id = '{bank_id}';
-    DROP INDEX CONCURRENTLY IF EXISTS idx_memory_units_embedding;
 """
 
+import os
 from collections.abc import Sequence
 
 from alembic import context, op
@@ -35,7 +30,7 @@ down_revision: str | Sequence[str] | None = "c3d4e5f6g7h8"
 branch_labels: str | Sequence[str] | None = None
 depends_on: str | Sequence[str] | None = None
 
-_HNSW_FACT_TYPES: dict[str, str] = {
+_FACT_TYPES: dict[str, str] = {
     "world": "worl",
     "experience": "expr",
     "observation": "obsv",
@@ -47,6 +42,17 @@ def _get_schema_prefix() -> str:
     return f'"{schema}".' if schema else ""
 
 
+def _vector_index_using_clause() -> str:
+    """Return the USING clause based on the configured vector extension."""
+    ext = os.getenv("HINDSIGHT_API_VECTOR_EXTENSION", "pgvector").lower()
+    if ext == "pgvectorscale":
+        return "USING diskann (embedding vector_cosine_ops) WITH (num_neighbors = 50)"
+    elif ext == "vchord":
+        return "USING vchordrq (embedding vector_l2_ops)"
+    else:
+        return "USING hnsw (embedding vector_cosine_ops)"
+
+
 def upgrade() -> None:
     schema = _get_schema_prefix()
 
@@ -56,33 +62,35 @@ def upgrade() -> None:
     )
     op.execute(f"ALTER TABLE {schema}banks ADD CONSTRAINT banks_internal_id_unique UNIQUE (internal_id)")
 
-    # 2. Drop any fact_type-only partial HNSW indexes that may exist from prior migrations
+    # 2. Drop any fact_type-only partial indexes that may exist from prior migrations
     #    (bank_id B-tree always wins over them when bank_id is in the WHERE clause)
     op.execute(f"DROP INDEX IF EXISTS {schema}idx_mu_emb_world")
     op.execute(f"DROP INDEX IF EXISTS {schema}idx_mu_emb_observation")
     op.execute(f"DROP INDEX IF EXISTS {schema}idx_mu_emb_experience")
 
-    # 4. Drop global HNSW index (competes with per-bank partial indexes)
+    # 4. Drop global vector index (competes with per-bank partial indexes)
     op.execute(f"DROP INDEX IF EXISTS {schema}idx_memory_units_embedding")
 
-    # 5. Create per-(bank, fact_type) partial HNSW indexes for all existing banks
+    # 5. Create per-(bank, fact_type) partial vector indexes for all existing banks
+    #    using the configured extension (HNSW / DiskANN / vchordrq)
     bind = op.get_bind()
     schema_name = context.config.get_main_option("target_schema")
     table_ref = f'"{schema_name}".memory_units' if schema_name else "memory_units"
     banks_ref = f'"{schema_name}".banks' if schema_name else "banks"
+    using_clause = _vector_index_using_clause()
 
     rows = bind.execute(text(f"SELECT bank_id, internal_id FROM {banks_ref}")).fetchall()  # noqa: S608
     for row in rows:
         bank_id = row[0]
         internal_id = str(row[1]).replace("-", "")[:16]
         escaped_bank_id = bank_id.replace("'", "''")
-        for ft, ft_short in _HNSW_FACT_TYPES.items():
+        for ft, ft_short in _FACT_TYPES.items():
             idx_name = f"idx_mu_emb_{ft_short}_{internal_id}"
             # Index name is schema-unqualified (indexes live in the schema of their table)
             bind.execute(
                 text(
                     f"CREATE INDEX IF NOT EXISTS {idx_name} "
-                    f"ON {table_ref} USING hnsw (embedding vector_cosine_ops) "
+                    f"ON {table_ref} {using_clause} "
                     f"WHERE fact_type = '{ft}' AND bank_id = '{escaped_bank_id}'"
                 )
             )

hindsight-api-slim/hindsight_api/engine/retain/bank_utils.py

@@ -137,7 +137,7 @@ async def get_bank_profile(pool, bank_id: str) -> BankProfile:
 
         # Bank doesn't exist, create with defaults.
         # Generate internal_id here so we control the value and can use it
-        # immediately for HNSW index creation without a RETURNING round-trip.
+        # immediately for vector index creation without a RETURNING round-trip.
         internal_id = uuid.uuid4()
         inserted = await conn.fetchval(
             f"""