This document refers to a deprecated version of the RQL programming language.
Reads many PARQUET AVRO files - directories or wildcards - from a file system location.
cache := <default interval>,
retries := <default int>, retry_interval := <default interval>)
Each file in a directory or wildcard match must be of compatible type. If each file contains a collection, then all files are UNIONed into a single large collection. Otherwise, all files are concatenated into a single large collection.