We have to delete nearly a million record on a daily basis. We currently have a batch which is scheduled and it deletes all the records. The batch is taking too much of time to delete these records. Is there any other way other than batch that deletes all these records with lesser time compared to the batch.
Thanks in advance
The fastest way would be to use an external API, which you could parallelize quite easily (but be aware of concurrent limits). As far as speeding up the batch, it won't go any faster than asynchronous code allows. Instead, you need to optimize any trigger logic, etc, so that you can delete records as fast as possible from the batch context, and set the batch's scope size to 2,000 to minimize the number of executions it needs.
The use case is still not clear on what exactly is creating 1M records per day that you want to delete later. But assuming you have a scenario (really large enterprise) to store millions of records on Salesforce and then to delete a subset of it on a specific date, you need to check few things:
Deletes are generally very fast. Things that cause slowdowns generally revolve around relationships to other objects.
If Apex is indeed performing poorly, then another option is to schedule Salesforce Data Loader or an ETL tool to identify the records, and hard delete them using the Bulk API or Bulk API 2.0. See Deleting Data from LDV guide
It can be slower to let a master-detail relationship delete child records. You may be better off deleting the children first, and then deleting the parents.
If you have parent relationships (especially to Account or an object that is then related to Account), make sure to sort by that relationship field and delete in order.
