Optiq is a framework that allows efficient translation of queries involving heterogeneous and federated data.
Optiq is a highly customizable engine for parsing and planning queries on data in a wide variety of formats. It allows database-like access, and in particular a SQL interface and advanced query optimization, for data not residing in a traditional database.
Databases were traditionally engineered in a monolithic stack, providing a data storage format, data processing algorithms, query parser, query planner, built-in functions, metadata repository and connectivity layer. They innovate in some areas but rarely in all.
Modern data management systems are decomposing that stack into separate components, separating data, processing engine, metadata, and query language support. They are highly heterogeneous, with data in multiple locations and formats, caching and redundant data, different workloads, and processing occurring in different engines.
Query planning (sometimes called query optimization) has always been a key function of a DBMS, because it allows the implementors to introduce new query-processing algorithms, and allows data administrators to re-organize the data without affecting applications built on that data. In a componentized system, the query planner integrates the components (data formats, engines, algorithms) without introducing unncessary coupling or performance tradeoffs.
But building a query planner is hard; many systems muddle along without a planner, and indeed a SQL interface, until the demand from their customers is overwhelming.
There is an opportunity to make this process more efficient by creating a re-usable framework.
Optiq allows database-like access, and in particular a SQL interface and advanced query optimization, for data not residing in a traditional database. It is complementary to many current Hadoop and NoSQL systems, which have innovative and performant storage and runtime systems but lack a SQL interface and intelligent query translation.
Optiq is already in use by several projects, including Apache Drill, Apache Hive and Cascading Lingual, and commercial products.
Optiq's architecture consists of:
An extensible relational algebra.
- SPIs (service-provider interfaces) for metadata (schemas and tables), planner rules, statistics, cost-estimates, user-defined functions.
- Built-in sets of rules for logical transformations and common data-sources.
- Two query planning engines driven by rules, statistics, etc. One engine is cost-based, the other rule-based.
- Optional SQL parser, validator and translator to relational algebra.
- Optional JDBC driver.
The initial goals are be to move the existing codebase to Apache and integrate with the Apache development process. Once this is accomplished, we plan for incremental development and releases that follow the Apache guidelines.
As we move the code into the org.apache namespace, we will restructure components as necessary to allow clients to use just the components of Optiq that they need.
A version 1.0 release, including pre-built binaries, will foster wider adoption.
Optiq has had over a dozen minor releases over the last 18 months. Its core SQL parser and validator, and its planning engine and core rules, are mature and robust and are the basis for several production systems; but other components and SPIs are still undergoing rapid evolution.
We plan to invest in supporting a meritocracy. We will discuss the requirements in an open forum. We encourage the companies and projects using Optiq to discuss their requirements in an open forum and to participate in development. We will encourage and monitor community participation so that privileges can be extended to those that contribute.
Optiq's pluggable architecture encourages developers to contribute extensions such as adapters for data sources, new planning rules, and better statistics and cost-estimation functions. We look forward to fostering a rich ecosystem of extensions.
Building a data management system requires a high degree of technical skill, and correspondingly, the community of developers directly using Optiq is potentially fairly small, albeit highly technical and engaged. But we also expect engagement from members of the communities of projects that use Optiq, such as Drill and Hive. And we intend to structure Optiq so that it can be used for lighter weight applications, such as providing a SQL and JDBC interface to a NoSQL system.
The developers on the initial committers list are all experienced open source developers, and are actively using Optiq in their projects.
- Julian Hyde is lead developer of Mondrian, an open source OLAP engine, and an Apache Drill committer.
- Chris Wensel is lead developer of Cascading, and of Lingual, the SQL interface to Cascading built using Optiq.
- Jacques Nadeau is lead developer of Apache Drill, which uses Optiq.
In addition, there are several regular contributors whom we hope will graduate to committers during the incubation process.
We realize that additional employer diversity is needed, and we will work aggressively to recruit developers from additional companies.
Apache, and in particular the ecosystem surrounding Hadoop, contains several projects for building data management systems that leverage each other's capabilities. Optiq is a natural fit for that ecosystem, and will help foster projects meeting new challenges.
Optiq is already used by Apache Hive and Apache Drill; Optiq embeds Apache Spark as an optional engine; we are in discussion with Apache Phoenix about integrating JDBC and query planning.
Optiq is already a key component in three independent projects, each backed by a different company, so the risk of being orphaned is relatively low. We plan to mitigate this risk by recruiting additional committers, and promoting Optiq's adoption as a framework by other projects.
Inexperience with Open Source
The initial committers are all Apache members, some of whom have several years in the Apache Hadoop community. The founder of the project, Julian Hyde, has been a founder and key developer in open source projects for over ten years.
The initial committers are employed by a number of companies, including Concurrent, Hortonworks, MapR Technologies and Salesforce.com. We are committed to recruiting additional committers from outside these companies.
Reliance on Salaried Developers
Like most open source projects, Optiq receives substantial support from salaried developers. This is to be expected given that it is a highly technical framework. However, they are all passionate about the project, and we are confident that the project will continue even if no salaried developers contribute to the project. As a framework, the project encourages the involvement of members of other projects, and of academic researchers. We are committed to recruiting additional committers including non-salaried developers.
Relationships with Other Apache Products
As mentioned in the Alignment section, Optiq is being used by Apache Hive and Apache Drill, and has adapters for Apache Phoenix and Apache Spark. Optiq often operates on data in a Hadoop environment, so collaboration with other Hadoop projects is desirable and highly likely.
Unsurprisingly there is some overlap in capabilities between Optiq and other Apache projects. Several projects that are databases or database-like have query-planning capabilities. These include Hive, Drill, Phoenix, Spark, Apache Derby, Apache Pig, Apache Jena and Apache Tajo. Optiq’s query planner is extensible at run time, and does not have a preferred runtime engine on which to execute compiled queries. These capabilities, and the large corpus of pre-built rules, are what allow Optiq to be embedded in other projects.
Several other Apache projects access third-party data sources, including Hive, Pig, Drill, Spark and Apache MetaModel. Optiq allows users to optimize access to third-party data sources by writing rules to push processing down to the data source, and provide a cost model to choose the optimal location for processing. That said, maintaining a library of adapters is burdensome, and so it would make sense to collaborate with other projects on adapter libraries, and re-use libraries where possible.
Optiq supports several front ends for submitting queries. The most popular is SQL, with driver connectivity via JDBC (and ODBC planned). Other Apache projects with a SQL parser include Hive, Spark, Phoenix, Derby, Tajo. Drill uses Optiq’s parser and JDBC stack; both Phoenix and Drill have expressed interest in collaborating on JDBC and ODBC. Optiq’s Linq4j API is similar to the fluent query-builder APIs in Spark and MetaModel. Use of a front end is not required; for instance, Hive integrates with Optiq by directly building a graph of RelNode objects.
An Excessive Fascination with the Apache Brand
Optiq solves a real problem, as evidenced by its take-up by other projects. This proposal is not for the purpose of generating publicity. Rather, the primary benefits to joining Apache are those outlined in the Rationale section.
Additional documentation for Optiq may be found on its github site:
The initial code codebase resides in three projects, all hosted on github:
Source and Intellectual Property Submission Plan
The initial codebase is already distributed under the Apache 2.0 License. The owners of the IP have indicated willingness to sign the SGA.
Optiq and Linq4j have the following external dependencies.
- Java 1.6, 1.7 or 1.8
- Apache Maven, Commons
- JavaCC (BSD license)
- Sqlline 1.1.6 (BSD license)
- Junit 4.11 (EPL)
- Janino (BSD license)
- Guava (Apache 2.0 license)
- Eigenbase-resgen, eigenbase-xom, eigenbase-properties (Apache 2.0 license)
Some of Optiq's adapters (optiq-csv, optiq-mongodb, optiq-spark, optiq-splunk) are currently developed alongside core Optiq, and have the following additional dependencies:
- Open CSV 2.3 (Apache 2.0 license)
- Apache Incubator Spark
- Mongo Java driver (Apache 2.0 license)
Upon acceptance to the incubator, we would begin a thorough analysis of all transitive dependencies to verify this information and introduce license checking into the build and release process by integrating with Apache Rat.
Optiq will eventually support encryption on the wire. This is not one of the initial goals, and we do not expect Optiq to be a controlled export item due to the use of encryption.
The Optiq team would like to use git for source control, due to our current use of git/github. We request a writeable git repo git://git.apache.org/incubator-optiq, and mirroring to be set up to github through INFRA.
Optiq currently uses the github issue tracking system associated with its github repo: https://github.com/julianhyde/optiq/issues. We will migrate to the Apache JIRA: http://issues.apache.org/jira/browse/OPTIQ.
- Julian Hyde (jhyde at apache dot org)
- Jacques Nadeau (jacques at apache dot org)
- James R. Taylor (jamestaylor at apache dot org)
- Chris Wensel (cwensel at apache dot org)
The initial committers are employees of Concurrent, Hortonworks, MapR and Salesforce.com.
- Julian Hyde (Hortonworks)
- Jacques Nadeau (MapR Technologies)
- James R. Taylor (Salesforce.com)
- Chris Wensel (Concurrent)
- Ashutosh Chauhan (hashutosh at apache dot org)
Ted Dunning (tdunning at apache dot org) – Chief Application Architect at MapR Technologies; committer for Lucene, Mahout and ZooKeeper.
- Alan Gates (gates at apache dot org) - Architect at Hortonworks; committer for Pig, Hive and others.
- Steven Noels (stevenn at apache dot org) - Chief Technical Officer at NGDATA; committer for Cocoon and Forrest, mentor for Phoenix.
The Apache Incubator.