A PARQUET file contains columnar data split into row groups. Apache Parquet is a column storage file format used by Hadoop. It provides data compression and encoding. Parquet files support efficient compression and encoding schemes resulting in optimized files. These file formats maximize querying data effectiveness using serverless technologies. Parquet is built from scratch using Google algorithm and Apache licensed.
Three letter file extensions are from restricted file lengths days. Longer names are common now like database.sqlite. We read and write Parquet files in R using arrow package. Parquet stores data from columns together in row groups. Binary Parquet files look like gibberish to humans compared to JSON or XML. Uncompressed CSV is 4 TB but Parquet is smaller.
When writing DataFrames to Parquet, column names and types are preserved. Parquet files have .parquet extension. DuckDB supports reading and writing Parquet files efficiently and pushing filters into scans.
Apache Hadoop
Pandas