Coral is a translation, analysis, and query rewrite engine for SQL and other relational languages.
Coral is a library for analyzing, processing, and rewriting views defined in the Hive Metastore, and sharing them across multiple execution engines. It performs SQL translations to enable views expressed in HiveQL (and potentially other languages) to be accessible in engines such as Trino (formerly PrestoSQL), Apache Spark, and Apache Pig. Coral not only translates view definitions between different SQL/non-SQL dialects, but also rewrites expressions to produce semantically equivalent ones, taking into account the semantics of the target language or engine. For example, it automatically composes new built-in expressions that are equivalent to each built-in expression in the source view definition. Additionally, it integrates with Transport UDFs to enable translating and executing user-defined functions (UDFs) across Hive, Trino, Spark, and Pig. Coral is under active development. Currently, we are looking into expanding the set of input view language APIs beyond HiveQL, and implementing query rewrite algorithms for data governance and query optimization.
Coral consists of following modules:
Clone the repository:
git clone https://github.com/linkedin/coral.git
The project is under active development and we welcome contributions of different forms. Please see the Contribution Agreement.