Databricks

Using Delta Time Travel what is the scalability limit for using the feature, at what point does the time travel become infeasible? 

What types of files does autoloader support for streaming ingestion ? I see good support for CSV and JSON, how can I ingest files like XML, avro, parquet etc ? would XML rely on Spark-XML ? 

What is the best way to deal with concurrent exceptions in Delta when you have multiple writers on the same delta table ?

using Spark SQL or particularly %SQL in a databricks notebook, is there a way to use pagination or offset or skip ? 

What is the best way to convert a very large parquet table to delta ? possibly without downtime!