Dataloader configuration

 Available in: Enterprise, Performance, Unlimited, and Developer editions

Open the Data Loader.

Select Settings | Settings.

Edit the fields as needed.

1. Field	Description
   Batch size	In a single insert, update, upsert, or delete operation, records moving to or from Salesforce are processed in increments of this size. The maximum is 200 records. We recommend a value between 50 and 100. The maximum value is 10,000 if the Use Bulk API option is selected.
   Insert null values	Select this option to insert blank mapped values as null values during data operations. When you are updating records, this option instructs Data Loader to overwrite existing data in mapped fields. This option is not available if the Use Bulk API option is selected. Empty field values are ignored when you update records using the Bulk API. To set a field value to null when the Use Bulk API option is selected, use a field value of #N/A.
   Assignment rule	Specify the ID of the assignment rule to use for inserts, updates, and upserts. This option applies to inserts, updates, and upserts on cases and leads. The assignment rule overrides Owner values in your CSV file.
   Server host	Enter the URL of the Salesforce server with which you want to communicate. For example, if you are loading data into a sandbox, change the URL to https://test.salesforce.com.
   Reset URL on Login	By default, Salesforce resets the URL after login to the one specified in Server host. To turn off this automatic reset, disable this option.
   Compression	Compression enhances the performance of Data Loader and is turned on by default. You might want to disable compression when debugging the underlying SOAP messages. To turn off compression, enable this option.
   Timeout	Specify how many seconds Data Loader waits to receive a response back from the server before returning an error for the request.
   Query request size	In a single export or query operation, records are returned from Salesforce in increments of this size. Larger values can improve performance but use more memory on the client. The default is 500; the minimum is 200, and the maximum is 2,000. There is no guarantee that the requested batch size requested is the actual batch size; changes are sometimes made to maximize performance.
   Generate status files for exports	Select this option to generate success and error files when exporting data.
   Read all CSVs with UTF-8 encoding	Select this option to force files to open in UTF-8 encoding, even if they were saved in a different format.
   Write all CSVs with UTF-8 encoding	Select this option to force files to be written in UTF-8 encoding.
   Use European date format	Select this option to support the date formats dd/MM/yyyy and dd/MM/yyyy HH:mm:ss.
   Allow field truncation	Select this option to truncate data in the following types of fields when loading that data into Salesforce: Email, Multi-select Picklist, Phone, Picklist, Text, and Text (Encrypted). In Data Loader versions 14.0 and earlier, Data Loader truncates values for fields of those types if they are too large. In Data Loader version 15.0 and later, the load operation fails if a value is specified that is too large. Selecting this option allows you to specify that the previous behavior, truncation, be used instead of the new behavior in Data Loader versions 15.0 and later. This option is selected by default and has no effect in versions 14.0 and earlier. This option is not available if the Use Bulk API option is selected. In that case, the load operation fails for the row if a value is specified that is too large for the field.
   Allow comma as a CSV delimiter	Select this option if your CSV file uses commas to delimit records.
   Allow tab as a CSV delimiter	Select this option if your CSV file uses tab characters to delimit records.
   Allow other characters as CSV delimiters	Select this option if your CSV file uses a character other than a comma or tab to delimit records.
   Other delimiters (enter multiple values with no separator; for example, !+?)	The characters in this field are used only if the Allow other characters as CSV delimiters option is selected. For example, if you use the | (pipe) character to delimit data records, enter that character in this field.
   Use Bulk API	Select this option to use Bulk API to insert, update, upsert, delete, and hard-delete records. Bulk API is optimized to load or delete many records asynchronously. It’s faster than the default SOAP-based API due to parallel processing and fewer network round-trips. Warning You can hard delete records when you configure Data Loader to Use Bulk API. Keep in mind that hard deleted records are immediately deleted and can’t be recovered from the Recycle Bin.
   Enable serial mode for Bulk API	To use serial processing instead of parallel processing for Bulk API, select this option. Processing in parallel can cause database contention. When contention is severe, the load can fail. Serial mode processes batches one at a time, however it can increase the processing time for a load. This option is only available if the Use Bulk API option is selected.
   Upload Bulk API Batch as Zip File	Select this option to use Bulk API to upload zip files containing binary attachments, such as Attachment records or Salesforce CRM Content. This option is only available if the Use Bulk API option is selected.
   Time Zone	Select this option to specify a default time zone. If a date value does not include a time zone, this value is used. If no value is specified, the time zone of the computer where Data Loader is installed is used. If an incorrect value is entered, GMT is used as the time zone and this fact is noted in the Data Loader log. Valid values are any time zone identifier which can be passed to the Java getTimeZone(java.lang.String) method. The value can be a full name such as America/Los_Angeles, or a custom ID such as GMT-8:00.
   Proxy host	The host name of the proxy server, if applicable.
   Proxy port	The proxy server port.
   Proxy username	The username for proxy server authentication.
   Proxy password	The password for proxy server authentication.
   Proxy NTLM domain	The name of the Windows domain used for NTLM authentication.
   Start at row	If your last operation failed, you can use this setting to begin where the last successful operation finished.

2. 
   
3. 
   
4. Click OK and save your settings.

Reference :  https://developer.salesforce.com/docs/atlas.en-us.dataLoader.meta/dataLoader/configuring_the_data_loader.htm