Allow updating quantizer to RQ, add bits to RQConfigUpdate

src/collections/config/classes.ts

@@ -186,15 +186,18 @@ export class MergeWithExisting {
     current: WeaviateVectorIndexConfig,
     update: VectorIndexConfigHNSWUpdate
   ): WeaviateVectorIndexConfig {
+    const hasOtherQuantizerAlready = (quantizer: string) =>
+      ['pq', 'bq', 'sq', 'rq'].some(
+        (q) => q !== quantizer && (current?.[q as keyof WeaviateVectorIndexConfig] as any)?.enabled
+      );
     if (
-      (QuantizerGuards.isBQUpdate(update.quantizer) &&
-        (((current?.pq as any) || {}).enabled || ((current?.sq as any) || {}).enabled)) ||
-      (QuantizerGuards.isPQUpdate(update.quantizer) &&
-        (((current?.bq as any) || {}).enabled || ((current?.sq as any) || {}).enabled)) ||
-      (QuantizerGuards.isSQUpdate(update.quantizer) &&
-        (((current?.pq as any) || {}).enabled || ((current?.bq as any) || {}).enabled))
-    )
+      (QuantizerGuards.isBQUpdate(update.quantizer) && hasOtherQuantizerAlready('bq')) ||
+      (QuantizerGuards.isPQUpdate(update.quantizer) && hasOtherQuantizerAlready('pq')) ||
+      (QuantizerGuards.isSQUpdate(update.quantizer) && hasOtherQuantizerAlready('sq')) ||
+      (QuantizerGuards.isRQUpdate(update.quantizer) && hasOtherQuantizerAlready('rq'))
+    ) {
       throw new WeaviateInvalidInputError(`Cannot update the quantizer type of an enabled vector index.`);
+    }
     const { quantizer, ...rest } = update;
     const merged: WeaviateVectorIndexConfig = { ...current, ...rest };
     if (QuantizerGuards.isBQUpdate(quantizer)) {
@@ -209,6 +212,10 @@ export class MergeWithExisting {
       const { type, ...quant } = quantizer;
       merged.sq = { ...current!.sq!, ...quant, enabled: true };
     }
+    if (QuantizerGuards.isRQUpdate(quantizer)) {
+      const { type, ...quant } = quantizer;
+      merged.rq = { ...current!.rq!, ...quant, enabled: true };
+    }
     return merged;
   }
 }

src/collections/config/unit.test.ts

@@ -332,6 +332,43 @@ describe('Unit testing of the MergeWithExisting class', () => {
     });
   });
 
+  it('should merge a RQ quantizer HNSW vectorIndexConfig with existing schema', () => {
+    const merged = MergeWithExisting.vectors(deepCopy(hnswVectorConfig), [
+      {
+        name: 'name',
+        vectorIndex: {
+          name: 'hnsw',
+          config: {
+            quantizer: {
+              type: 'rq',
+              rescoreLimit: 1000,
+              bits: 128,
+            },
+          },
+        },
+      },
+    ]);
+    expect(merged).toEqual({
+      name: {
+        vectorIndexConfig: {
+          ...hnswVectorConfig.name.vectorIndexConfig,
+          rq: {
+            enabled: true,
+            rescoreLimit: 1000,
+            bits: 128,
+          },
+        },
+        vectorIndexType: 'hnsw',
+        vectorizer: {
+          'text2vec-contextionary': {
+            properties: ['name'],
+            vectorizeCollectionName: false,
+          },
+        },
+      },
+    });
+  });
+
   it('should merge a BQ quantizer Flat vectorIndexConfig with existing schema', () => {
     const merged = MergeWithExisting.vectors(deepCopy(flatVectorConfig), [
       {

src/collections/configure/types/vectorIndex.ts

@@ -23,6 +23,7 @@ export type QuantizerRecursivePartial<T> = {
 export type RQConfigCreate = QuantizerRecursivePartial<RQConfig>;
 
 export type RQConfigUpdate = {
+  bit?: number;
   rescoreLimit?: number;
   type: 'rq';
 };