Скачать или смотреть Salesforce Dataloader, Limitations - Salesforce Cards

This explains Dataloader basics, Limitations, and interview questions about Dataloader. We can find how to enable the features in Dataloader also.
1) How to insert null values into dataloader?

Enable 'insert null values' checkbox in the dataloader.

2) How many records can upload using Dataloader ?

Dataloader supports upto 5 million records.

3) Which operations can perform using dataloader?

-Insert,Update,Upsert,Delete,HardDelete,Export,Export all

4) What is default batch size if we enable bulk API?

2000 records

5) What is the filed mapping file format of the data loader?

SDL (Salesforce Data Loader)

6)How to enable Hard Delete button of data loader.

Go to setting of data loader and enable Bulk API checkbox.