Apache ORC

Apache ORC columnar storage format reference.

Commands

| Command | Description | |---------|-------------| | intro | ORC overview, file structure, vs Parquet | | schema | Types, complex types, schema evolution | | compression | ZLIB/SNAPPY/LZO/ZSTD codecs, ratios | | read | orc-tools CLI, Python/Java read APIs | | write | Writer APIs, stripe/buffer sizing | | hive | Hive integration, ACID transactions | | spark | Spark ORC read/write, pushdown | | performance | Bloom filters, indexes, vectorized reads |