feat: remote index stats (#1702)

BREAKING CHANGE: the return value of `index_stats` method has changed
and all `index_stats` APIs now take index name instead of UUID. Also
several deprecated index statistics methods were removed.

* Removes deprecated methods for individual index statistics
* Aligns public `IndexStatistics` struct with API response from LanceDB
Cloud.
* Implements `index_stats` for remote Rust SDK and Python async API.

node/src/index.ts

@@ -724,9 +724,9 @@ export interface VectorIndex {
 export interface IndexStats {
   numIndexedRows: number | null
   numUnindexedRows: number | null
-  indexType: string | null
-  distanceType: string | null
-  completedAt: string | null
+  indexType: string
+  distanceType?: string
+  numIndices?: number
 }
 
 /**

node/src/query.ts

@@ -112,7 +112,7 @@ export class Query<T = number[]> {
     return this
   }
 
-  /** 
+  /**
    * Skip searching un-indexed data. This can make search faster, but will miss
    * any data that is not yet indexed.
    */

node/src/remote/client.ts

@@ -17,7 +17,7 @@ import axios, { type AxiosResponse, type ResponseType } from 'axios'
 import { tableFromIPC, type Table as ArrowTable } from 'apache-arrow'
 
 import { type RemoteResponse, type RemoteRequest, Method } from '../middleware'
-import { MetricType } from '..'
+import type { MetricType } from '..'
 
 interface HttpLancedbClientMiddleware {
   onRemoteRequest(

node/src/remote/index.ts

@@ -526,8 +526,7 @@ export class RemoteTable<T = number[]> implements Table<T> {
       numIndexedRows: body?.num_indexed_rows,
       numUnindexedRows: body?.num_unindexed_rows,
       indexType: body?.index_type,
-      distanceType: body?.distance_type,
-      completedAt: body?.completed_at
+      distanceType: body?.distance_type
     }
   }
 

node/src/test/test.ts

@@ -888,9 +888,12 @@ describe("LanceDB client", function () {
       expect(indices[0].columns).to.have.lengthOf(1);
       expect(indices[0].columns[0]).to.equal("vector");
 
-      const stats = await table.indexStats(indices[0].uuid);
+      const stats = await table.indexStats(indices[0].name);
       expect(stats.numIndexedRows).to.equal(300);
       expect(stats.numUnindexedRows).to.equal(0);
+      expect(stats.indexType).to.equal("IVF_PQ");
+      expect(stats.distanceType).to.equal("l2");
+      expect(stats.numIndices).to.equal(1);
     }).timeout(50_000);
   });