feat: expose use_index in LanceDB OSS

node/src/query.ts

@@ -33,6 +33,7 @@ export class Query<T = number[]> {
   private _filter?: string
   private _metricType?: MetricType
   protected readonly _embeddings?: EmbeddingFunction<T>
+  private _useIndex: boolean
 
   constructor (query: T, tbl?: any, embeddings?: EmbeddingFunction<T>) {
     this._tbl = tbl
@@ -44,6 +45,7 @@ export class Query<T = number[]> {
     this._filter = undefined
     this._metricType = undefined
     this._embeddings = embeddings
+    this._useIndex = true
   }
 
   /***
@@ -102,6 +104,20 @@ export class Query<T = number[]> {
     return this
   }
 
+  /**
+     * Whether or not to use the ANN index for this query. If set to false,
+     * the query will run exact KNN on a full scan of the table. The default is
+     * true (use the index).
+     *
+     * Setting this option to false is not currently supported by LanceDB Cloud.
+     *
+     * @param value Whether or not to use the index for this query.
+     */
+  useIndex (value: boolean): Query<T> {
+    this._useIndex = value
+    return this
+  }
+
   /**
      * Execute the query and return the results as an Array of Objects
      */

node/src/test/test.ts

@@ -117,6 +117,19 @@ describe('LanceDB client', function () {
       assert.isUndefined(results[0].name)
       assert.isUndefined(results[0].price)
     })
+
+    it('can choose to do flat search', async function () {
+      const uri = await createTestDB()
+      const con = await lancedb.connect(uri)
+      const table = await con.openTable('vectors')
+      const results = await table.search([0.1, 0.3]).useIndex(false).execute()
+
+      assert.equal(results.length, 2)
+      assert.equal(results[0].price, 10)
+      const vector = results[0].vector as Float32Array
+      assert.approximately(vector[0], 0.0, 0.2)
+      assert.approximately(vector[0], 0.1, 0.3)
+    })
   })
 
   describe('when creating a new dataset', function () {
@@ -385,11 +398,13 @@ describe('Query object', function () {
       .metricType(MetricType.Cosine)
       .refineFactor(100)
       .select(['a', 'b'])
+      .useIndex(false)
       .nprobes(20) as Record<string, any>
     assert.equal(query._limit, 1)
     assert.equal(query._metricType, MetricType.Cosine)
     assert.equal(query._refineFactor, 100)
     assert.equal(query._nprobes, 20)
+    assert.equal(query._useIndex, false)
     assert.deepEqual(query._select, ['a', 'b'])
   })
 })