# [FAQ] TiFlash 查询报错 DB::Exception: Memory limit (for query) exceeded

## Key Words

Memory limit (for query) exceeded

## Description

SQL 查询时遇到 TiFlash 报错

```sql
ERROR: other error for mpp stream: DB::Exception: Exchange receiver meet error : DB::Exception: Memory limit (for query) exceeded: would use 9.39 GiB (attempt to allocate chunk of 128974848 bytes), maximum: 9.31 GiB
```

## Content

与两个参数 max_memory_usage 和 max_memory_usage_for_all_queries 有关, 请检查两个参数值是否达到了上限  

```sql
profiles.default.max_memory_usage = 单条 sql 的内存限制  

profiles.default.max_memory_usage_for_all_queries = 总的查询内存限制  
```

具体配置请参考 [tiflash-configuration](https://docs.pingcap.com/zh/tidb/stable/tiflash-configuration#tiflash-%E9%85%8D%E7%BD%AE%E5%8F%82%E6%95%B0-1)

## 备注

在 v5.3.1 以下版本可能存在以下问题，请谨慎开启  
开启 max_memory_usage 和 max_memory_usage_for_all_queries 配置项时，存在 TiFlash 崩溃的问题