· Parquet and the Next Formats · #parquet #storage #file-formats #performance
What's Actually Inside Your Parquet File
Everyone treats Parquet as 'the fast columnar format' and stops there. But two files with identical rows can differ tenfold in scan cost, and the reason is never in the data - it's in the layout. Row group sizing, dictionary vs plain encoding, the compression codec, and whether min/max statistics actually let the engine skip pages: these are the dials that decide your query bill. This is a tour of the bytes most people never look at, and a free, 100%-in-browser way to look at your own.
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