When the system variable
tidb_enable_tmp_storage_on_oom is set to
ON, if the memory usage of a single SQL statement exceeds the limit of the system variable
tidb_mem_quota_query, some operators can save the intermediate results during execution as a temporary file to the disk and delete the file after the query is completed.
You can enable encryption for disk spill to prevent attackers from accessing data by reading these temporary files.
To enable encryption for the disk spill files, you can configure the item
spilled-file-encryption-method in the
[security] section of the TiDB configuration file.
[security] spilled-file-encryption-method = "aes128-ctr"
Value options for
plaintext. The default value is
plaintext, which means that encryption is disabled.