orc

# 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 |