How to insert duplicate values using Salesforce DataLoader?

Hi Ravi,

The Dataloader process the records in batches and check for duplicates in each batch. The default batch size is 200 records. So what you can do is, set batch to such a number that the batch does not contain duplicate records and use Upsert DML instead of Insert. In such a way the Data Loader will not give any error, as no batch will contain duplicate. For changing batch size you can follow steps as below -

1. If you are using Data Loader manually then please go to Settings and find Batch Size. You can change the batch size as per your requirement.
2. If you are using Data Loader with the command line then go to the XML file and find<entry key="sfdc.loadBatchSize" value="200"/>. Now change the value to let say 10 as <entry key="sfdc.loadBatchSize" value="10"/>

If you are not able to formulate a suitable batch size, then you can set the batch size to 1. Although it will increase the processing time by 200 times, it's worth to give it a try.

Please let me know if you are still facing any issue/error.

Thanks,

Subhendu