# Columnar Data Structures ## Benefits of Columnar Storage - Efficiency, as irrelevant data can be skipped. As a result, aggregation can be really fast. High throughput can be achieved. - Flexible in compression and efficient in encoding, as each column only contains one type of data. And as a result reduces the space. - Potentially reduces the cost, as certain cloud service charges based on the amount of data stored or scanned per query. > This approach is best especially for those queries that need to read certain > columns from a large table. Parquet can only read the _needed columns_ > therefore greatly **minimizing the IO**. ![[record-vs-column-oriented.png]] A graph from [[database/dremel]] paper explaining the difference between record-oriented storage and column-oriented storage.