Creating Index if source is csv or parquet files

If source of pds is csv files or parquet files. How can we create index on some columns to make queries response time faster.

You can build multiple reflections on this dataset with each reflection designed for different user query access patterns. These reflections are basically covering indexes. There are many other use cases for reflections here: Dremio

If your data size is large enough, you should be thinking about your reflection’s partition and sort design.