fix(redshift-driver): Fix empty tableColumnTypes for external (Spectrum) tables (#9251)

Author: KSDaemon

packages/cubejs-redshift-driver/src/RedshiftDriver.ts

@@ -16,6 +16,7 @@ import {
   StreamOptions,
   StreamTableDataWithTypes,
   TableColumn,
+  TableStructure,
   UnloadOptions
 } from '@cubejs-backend/base-driver';
 import crypto from 'crypto';
@@ -341,6 +342,19 @@ export class RedshiftDriver extends PostgresDriver<RedshiftDriverConfiguration>
     // @todo Implement for Redshift, column \"typcategory\" does not exist in pg_type
   }
 
+  public override async tableColumnTypes(table: string): Promise<TableStructure> {
+    const [schema, name] = table.split('.');
+
+    // We might get table from Spectrum schema, so common request via `information_schema.columns`
+    // won't return anything. `getColumnsForSpecificTables` is aware of Spectrum tables.
+    const columns = await this.getColumnsForSpecificTables([{
+      schema_name: schema,
+      table_name: name,
+    }]);
+
+    return columns.map(c => ({ name: c.column_name, type: this.toGenericType(c.data_type) }));
+  }
+
   public async isUnloadSupported() {
     if (this.config.exportBucket) {
       return true;

packages/cubejs-testing-drivers/src/tests/testExternalSchemas.ts

@@ -46,4 +46,16 @@ export function redshiftExternalSchemasSuite(
       expect(it.data_type).toEqual(expect.any(String));
     });
   });
+
+  execute('should load columns types for external table', async () => {
+    const columnsForTables = await driver().tableColumnTypes(`${EXTERNAL_SCHEMA}.${EXTERNAL_TABLE}`);
+
+    expect(columnsForTables).toBeInstanceOf(Array);
+    expect(columnsForTables.length).toBeGreaterThan(0);
+
+    columnsForTables.forEach((it) => {
+      expect(it.name).toEqual(expect.any(String));
+      expect(it.type).toEqual(expect.any(String));
+    });
+  });
 }