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lancedb/nodejs/vectordb/table.ts

106 lines
2.9 KiB
TypeScript

// Copyright 2024 Lance Developers.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import { Schema, tableFromIPC } from "apache-arrow";
import { Table as _NativeTable } from "./native";
import { toBuffer, Data } from "./arrow";
import { Query } from "./query";
import { IndexBuilder } from "./indexer";
/**
* A LanceDB Table is the collection of Records.
*
* Each Record has one or more vector fields.
*/
export class Table {
private readonly inner: _NativeTable;
/** Construct a Table. Internal use only. */
constructor(inner: _NativeTable) {
this.inner = inner;
}
/** Get the schema of the table. */
get schema(): Schema {
const schemaBuf = this.inner.schema();
const tbl = tableFromIPC(schemaBuf);
return tbl.schema;
}
/**
* Insert records into this Table.
*
* @param {Data} data Records to be inserted into the Table
* @return The number of rows added to the table
*/
async add(data: Data): Promise<void> {
const buffer = toBuffer(data);
await this.inner.add(buffer);
}
/** Count the total number of rows in the dataset. */
async countRows(): Promise<bigint> {
return await this.inner.countRows();
}
/** Delete the rows that satisfy the predicate. */
async delete(predicate: string): Promise<void> {
await this.inner.delete(predicate);
}
/** Create an index over the columns.
*
* @param {string} column The column to create the index on. If not specified,
* it will create an index on vector field.
*
* @example
*
* By default, it creates vector idnex on one vector column.
*
* ```typescript
* const table = await conn.openTable("my_table");
* await table.createIndex().build();
* ```
*
* You can specify `IVF_PQ` parameters via `ivf_pq({})` call.
* ```typescript
* const table = await conn.openTable("my_table");
* await table.createIndex("my_vec_col")
* .ivf_pq({ num_partitions: 128, num_sub_vectors: 16 })
* .build();
* ```
*
* Or create a Scalar index
*
* ```typescript
* await table.createIndex("my_float_col").build();
* ```
*/
createIndex(column?: string): IndexBuilder {
let builder = new IndexBuilder(this.inner);
if (column !== undefined) {
builder = builder.column(column);
}
return builder;
}
search(vector?: number[]): Query {
const q = new Query(this);
if (vector !== undefined) {
q.vector(vector);
}
return q;
}
}