About this page

A short list rather than a directory. These are the pages that answer most day-to-day questions, plus the repositories worth opening when only the source settles an argument.

Documentation URLs containing latest follow the current release. If you are on an older line, change the version in the URL before trusting a default.

Apache Spark

Link	Why
Spark website	Releases and news
Documentation	Entry point for the version you are running
Configuration reference	Every property, its default and the version it appeared in
Spark SQL guide	DataFrame and SQL semantics
Structured Streaming guide	Triggers, watermarks and output modes
SQL performance tuning	AQE, join hints and partition coalescing
apache/spark on GitHub	Where a default is finally confirmed

Apache Hudi

Link	Why
Hudi website	Releases and blog
Overview	The timeline, file groups and file slices
Table types	Copy-on-Write versus Merge-on-Read, and the query types each supports
Indexes	Choosing between bloom, bucket, simple and the record-level indexes
Configuration reference	Every `hoodie.*` key, with defaults and since-versions
apache/hudi on GitHub	Config defaults and behaviour, at a release tag

Apache Iceberg

Link	Why
Iceberg website	Releases and the version support matrix
Documentation	Entry point for the current release
Table spec	The format itself: manifests, snapshots, deletes and deletion vectors
Spark getting started	The runtime coordinate and session extensions
Spark procedures	`rewrite_data_files`, `expire_snapshots` and the rest of the `CALL` surface
apache/iceberg on GitHub	The Spark and Scala support matrix lives in the build files

Other table formats

Link	Why
Apache XTable	Exposing one table format as another by converting metadata
Delta Lake documentation	Protocol, table features and maintenance
Apache Paimon	Streaming-first lakehouse format

File formats

Link	Why
Parquet documentation	File layout, encodings and statistics
apache/parquet-java on GitHub	Formerly `parquet-mr`, and where `parquet-cli` lives
Apache Avro documentation	Schemas and schema resolution rules

Query engines and streaming

Link	Why
Trino documentation	Connector reference, including Hudi, Iceberg and Delta
Kafka documentation	Broker, producer and consumer configuration
Flink documentation	Stable docs, including the table and SQL APIs

Platform

Link	Why
Apache Hadoop	HDFS and YARN, still underneath a lot of this
Apache Hive	Metastore, which most catalogs still talk to
Scala	The binary-compatibility rules that decide your artifact suffix