# General Options

__*Dumpling export SQL file*__

+ **`-h`**: `TiDB` server address
+ **`-P`**: `TiDB` server port
+ **`-u`**: `TiDB` username
+ **`-p`**: User password for authentication
+ **`-o`**: Specifies the export directory, which supports a local file path or a `URL` of an external storage
+ **`-t`**: Specifies the number of threads for the export 
+ **`-r`**: Specifies the maximum number of rows in a single file
+ **`-F`**: Specifies the maximum size of a single file

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The `-h`, `-p`, and `-u` option respectively mean the address, the port, and the user. If a password is required for authentication, you can use `-p $YOUR_SECRET_PASSWORD` to pass the password to `Dumpling`.

The `-o` option specifies the export directory of the storage, which supports a local file path or a `URL` of an external storage.

The `-t` option specifies the number of threads for the export. Increasing the number of threads improves the concurrency of `Dumpling` and the export speed, and also increases the database's memory consumption. Therefore, it is not recommended to set the number too large. Usually, it's less than `64`.

The `-r` option specifies the maximum number of rows in a single file. With this option specified, `Dumpling` enables the in-table concurrency to speed up the export and reduce the memory usage. When the upstream database is `TiDB v3.0` or later versions, a value of this parameter greater than 0 indicates that the `TiDB` region information is used for splitting and the value specified here will no longer take effect.

The `-F` option is used to specify the maximum size of a single file (the unit here is `MiB`; inputs like `5 GiB` or `8 KB` are also acceptable). It is recommended to keep its value to `256 MiB` or less if you plan to use `TiDB Lightning` to load this file into a `TiDB` instance.