diff --git a/libs/postgres-client/src/client.ts b/libs/postgres-client/src/client.ts
index 5526f65..a50d324 100644
--- a/libs/postgres-client/src/client.ts
+++ b/libs/postgres-client/src/client.ts
@@ -224,7 +224,7 @@ export class PostgreSQLClient {
     }
 
     const { chunkSize = 1000, excludeColumns = [] } = options;
-    const columns = Object.keys(data[0]).filter(col => !excludeColumns.includes(col));
+    const columns = Object.keys(data[0] ?? {}).filter(col => !excludeColumns.includes(col));
     const updateColumns = columns.filter(col => col !== conflictColumn);
 
     let totalInserted = 0;
diff --git a/libs/postgres-client/src/transactions.ts b/libs/postgres-client/src/transactions.ts
index 4506ded..47f2587 100644
--- a/libs/postgres-client/src/transactions.ts
+++ b/libs/postgres-client/src/transactions.ts
@@ -1,4 +1,3 @@
-import { PoolClient } from 'pg';
 import { getLogger } from '@stock-bot/logger';
 import type { PostgreSQLClient } from './client';
 import type { TransactionCallback } from './types';
diff --git a/libs/postgres-client/src/types.ts b/libs/postgres-client/src/types.ts
index 614c0a5..0caf612 100644
--- a/libs/postgres-client/src/types.ts
+++ b/libs/postgres-client/src/types.ts
@@ -1,4 +1,4 @@
-import type { QueryResult as PgQueryResult, Pool, PoolClient, QueryResultRow } from 'pg';
+import type { QueryResult as PgQueryResult, PoolClient, QueryResultRow } from 'pg';
 
 /**
  * PostgreSQL Client Configuration
diff --git a/libs/questdb-client/src/client.ts b/libs/questdb-client/src/client.ts
index 9080b42..b3121f7 100644
--- a/libs/questdb-client/src/client.ts
+++ b/libs/questdb-client/src/client.ts
@@ -5,8 +5,6 @@ import { QuestDBInfluxWriter } from './influx-writer';
 import { QuestDBQueryBuilder } from './query-builder';
 import { QuestDBSchemaManager } from './schema';
 import type {
-  BaseTimeSeriesData,
-  InsertResult,
   QueryResult,
   QuestDBClientConfig,
   QuestDBConnectionOptions,
@@ -226,7 +224,7 @@ export class QuestDBClient {
     table: TableNames,
     columns: string[],
     interval: string,
-    timeColumn: string = 'timestamp',
+    _timeColumn: string = 'timestamp',
     where?: string,
     params?: any[]
   ): Promise<QueryResult<T>> {