feat(langchain-community): add custom schema option for neon vector store

docs/core_docs/docs/integrations/vectorstores/neon.mdx

@@ -47,6 +47,15 @@ const vectorStore = await NeonPostgres.initialize(embeddings, {
 });
 ```
 
+### Optional
+You can put the vector store table in custom db schema by passing `schemaName` to the config options during initialization.
+```typescript
+const vectorStore = await NeonPostgres.initialize(embeddings, {
+  connectionString: NEON_POSTGRES_CONNECTION_STRING,
+  schemaName: "mycustomschema"
+});
+```
+
 ## Usage
 
 import CodeBlock from "@theme/CodeBlock";

libs/langchain-community/src/vectorstores/neon.ts

@@ -14,6 +14,7 @@ type Metadata = Record<string, string | number | Record<"in", string[]>>;
 export interface NeonPostgresArgs {
   connectionString: string;
   tableName?: string;
+  schemaName?: string;
   columns?: {
     idColumnName?: string;
     vectorColumnName?: string;
@@ -35,6 +36,8 @@ export class NeonPostgres extends VectorStore {
 
   tableName: string;
 
+  schemaName?: string;
+
   idColumnName: string;
 
   vectorColumnName: string;
@@ -60,6 +63,7 @@ export class NeonPostgres extends VectorStore {
 
     this.neonConnectionString = config.connectionString;
     this.tableName = config.tableName ?? "vectorstore_documents";
+    this.schemaName = config.schemaName;
     this.filter = config.filter;
 
     this.vectorColumnName = config.columns?.vectorColumnName ?? "embedding";
@@ -68,6 +72,12 @@ export class NeonPostgres extends VectorStore {
     this.metadataColumnName = config.columns?.metadataColumnName ?? "metadata";
   }
 
+  get computedTableName() {
+    return typeof this.schemaName !== "string"
+      ? `${this.tableName}`
+      : `"${this.schemaName}"."${this.tableName}"`;
+  }
+
   /**
    * Static method to create a new `NeonPostgres` instance from a
    * connection. It creates a table if one does not exist.
@@ -102,7 +112,7 @@ export class NeonPostgres extends VectorStore {
       return `(${row.map((_, j) => `$${base + 1 + j}`)})`;
     });
     const queryString = `
-    INSERT INTO ${this.tableName} (
+    INSERT INTO ${this.computedTableName} (
         ${useIdColumn ? `${this.idColumnName},` : ""}
         ${this.contentColumnName}, 
         ${this.vectorColumnName}, 
@@ -222,7 +232,7 @@ export class NeonPostgres extends VectorStore {
       : "";
     const queryString = `
       SELECT *, ${this.vectorColumnName} <=> $1 as "_distance"
-      FROM ${this.tableName}
+      FROM ${this.computedTableName}
       ${whereClause}
       ORDER BY "_distance" ASC
       LIMIT $2;`;
@@ -276,7 +286,7 @@ export class NeonPostgres extends VectorStore {
 
     if (params.ids !== undefined) {
       await sql(
-        `DELETE FROM ${this.tableName} 
+        `DELETE FROM ${this.computedTableName} 
         WHERE ${this.idColumnName} 
         IN (${params.ids.map((_, idx) => `$${idx + 1}`)})`,
         params.ids
@@ -297,8 +307,9 @@ export class NeonPostgres extends VectorStore {
 
     await sql(`CREATE EXTENSION IF NOT EXISTS vector;`);
     await sql(`CREATE EXTENSION IF NOT EXISTS "uuid-ossp";`);
+
     await sql(`
-      CREATE TABLE IF NOT EXISTS ${this.tableName} (
+      CREATE TABLE IF NOT EXISTS ${this.computedTableName} (
         ${this.idColumnName} uuid NOT NULL DEFAULT uuid_generate_v4() PRIMARY KEY,
         ${this.contentColumnName} text,
         ${this.metadataColumnName} jsonb,

libs/langchain-community/src/vectorstores/tests/neon.test.ts

@@ -0,0 +1,31 @@
+import { test, expect, describe } from "@jest/globals";
+import { FakeEmbeddings } from "@langchain/core/utils/testing";
+import { NeonPostgres } from "../neon.js";
+
+describe("NeonPostgres schemaName handling", () => {
+  const fakeEmbeddings = new FakeEmbeddings();
+
+  const baseConfig = {
+    connectionString: "postgres://user:pass@localhost:5432/db",
+    tableName: "vector_store",
+  };
+
+  test("uses only tableName when schemaName is not provided", () => {
+    const store = new NeonPostgres(fakeEmbeddings, {
+      ...baseConfig,
+    });
+
+    expect(store.schemaName).toBeUndefined();
+    expect(store.computedTableName).toBe("vector_store");
+  });
+
+  test("uses schemaName and tableName when schemaName is provided", () => {
+    const store = new NeonPostgres(fakeEmbeddings, {
+      ...baseConfig,
+      schemaName: "custom_schema",
+    });
+
+    expect(store.schemaName).toBe("custom_schema");
+    expect(store.computedTableName).toBe('"custom_schema"."vector_store"');
+  });
+});