# Adjust Tidb Server Parameters (B)

+ Enable ephemeral disks
  + oom-use-tmp-storage 
  + tmp-storage-path
  + tmp-storage-quota

![left](./student-guide/diagram/23-parameter-02-01.png)

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  - oom-use-tmp-storage
    - Set whether to enable ephemeral disks for certain operators when memory usage for a single SQL statement exceeds the mem-quota-query limit. Default is true
  - tmp-storage-path
    - Temporary disk storage location for some operators when the memory usage of a single SQL statement exceeds the mem-quota-query limit.
    - The default value is: <操作系统临时文件夹><操作系统用户ID> <host><port><statusHost><statusPort>/tmp-storage for the base64 encoded result of /_tidb/:/:.
  - tmp-storage-quota
    - The limit for tmp-storage-path storage usage, in bytes. When a single SQL statement uses temporary disks, causing the total number of temporary disks of the TiDB Server to exceed tmp-storage-quota, the current SQL operation is canceled and Out Of Global Storage Quota! Wrong.
    - When tmp-storage-quota is less than 0, there are no checks and restrictions listed above.