Orc

Apache ORC columnar storage format reference. File structure with stripes and indexes, schema types with evolution rules, compression codecs (ZLIB/SNAPPY/ZSTD), orc-tools CLI, Python/Java writer APIs, Hive ACID transactions, Spark integration, and performance tuning with bloom filters.

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