# Case Study: Hotspot (Continue...)

![`smart`](HotspotScheduler_aa_001_20221029.png)

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Equivalent statements to change a variable at global scope:
```
SET @@GLOBAL.tidb_distsql_scan_concurrency = 10;
SET GLOBAL TIDB_distsql_scan_concurrency = 10;
```

Equivalent statements to change a variable at session scope:
```
SET tidb_distsql_scan_concurrency = 10;
SET SESSION tidb_distsql_scan_concurrency = 10;
```

Please refer to `https://docs.pingcap.com/zh/tidb/stable/system-variables` for detail.