Phoenix: A SQL skin over HBase
'We put the SQL back in NoSQL'
Phoenix is a SQL skin over HBase, delivered as a client-embedded JDBC driver, powering the HBase use cases at Salesforce.com. Phoenix targets low-latency queries (milliseconds), as opposed to batch operation via map/reduce. To see what's supported, go to our language reference guide, and read more on our wiki.
Become the standard means of accessing HBase data through a well-defined, industry standard API.
How It Works
The Phoenix query engine transforms your SQL query into one or more HBase scans, and orchestrates their execution to produce standard JDBC result sets. Direct use of the HBase API, along with coprocessors and custom filters, results in performance on the order of milliseconds for small queries, or seconds for tens of millions of rows.
Tables are created and altered through DDL statements, and their schema is stored and versioned on the server in an HBase table. Columns are defined as either being part of a multi-part row key, or as key/value cells. You can also map Phoenix on to existing tables (see the wiki for more details).
Applications interact with Phoenix through a standard JDBC interface; all the usual interfaces are supported, including
ResultSet. The driver class is
com.salesforce.phoenix.jdbc.PhoenixDriver, and the connection url is
jdbc:phoenix: followed by the zookeeper quorum hostname specification plus optionally the port number and/or root node. For example:
Class.forName("com.salesforce.phoenix.jdbc.PhoenixDriver"); Connection conn = DriverManager.getConnection("jdbc:phoenix:localhost");
- HBase v 0.94.4 or above
- JDK 6 or higher
- All the system requirements
- Maven 3.X (https://maven.apache.org/)
To install a pre-built phoenix, use these directions:
- Download and expand the latest phoenix-[version]-install.tar from download page
- Remove prior phoenix-[version].jar from every HBase region server.
- Add the phoenix-[version].jar to the classpath of every HBase region server. An easy way to do this is to copy it into the HBase lib directory.
- Restart all region servers.
- Remove prior phoenix-[version]-client.jar from the classpath of any Phoenix client.
- Add the phoenix-[version]-client.jar to the classpath of any Phoenix client.
Alternatively, you can build it yourself using maven by following these build instructions.
Squirrel SQL Client
One way to experiment with Phoenix is to download and install a SQL client such as SQuirrel. Since Phoenix is a JDBC driver, integration with tools such as this are seamless. Here are the setup steps necessary:
- Remove prior phoenix-[version]-client.jar from the lib directory of SQuirrel
- Copy the phoenix-[version]-client.jar into the lib directory of SQuirrel
- Start SQuirrel and add new driver to SQuirrel (Drivers -> New Driver)
- In Add Driver dialog box, set Name to Phoenix
- Press List Drivers button and com.salesforce.phoenix.jdbc.PhoenixDriver should be automatically populated in the Class Name textbox. Press OK to close this dialog.
- Switch to Alias tab and create the new Alias (Aliases -> New Aliases)
- In the dialog box, Name: any name, Driver: Phoenix, User Name: anything, Password: anything
- Construct URL as follows: jdbc:phoenix: zookeeper quorum server. For example, to connect to a local HBase use: jdbc:phoenix:localhost
- Press Test (which should succeed if everything is setup correctly) and press OK to close.
- Now double click on your newly created Phoenix alias and click Connect. Now you are ready to run SQL queries against Phoenix.
Through SQuirrel, you can issue SQL statements in the SQL tab (create tables, insert data, run queries), and inspect table metadata in the Object tab (i.e. list tables, their columns, primary keys, and types).
In addition, you can use the bin/psql.sh to execute SQL and/or load CSV data directly. Here are few examples:
$ psql.sh localhost ../examples/stock_symbol.sql $ psql.sh localhost localhost ../examples/web_stat.sql ../examples/web_stat.csv ../examples/web_stat_queries.sql $ psql.sh -t stock_symbol -h symbol,price,date localhost ../examples/stock_symbol.sql
Currently, Phoenix hosts its own maven repository in github. This is done for convience and will later be moved to a 'real' maven repository. You can add it to your mavenized project by adding the following to your pom:
<repositories> ... <repository> <id>phoenix-github</id> <name>Phoenix Github Maven</name> <url>http://github.com/forcedotcom/Phoenix/tree/maven-artifacts/</url> <snapshots> <enabled>true</enabled> </snapshots> <releases> <enabled>true</enabled> </releases> </repository> ... </repositories> <dependencies> ... <dependency> <groupId>com.salesforce</groupId> <artifactId>phoenix</artifactId> <version>1.1</version> ... </dependency>
The best place to see samples are in our unit tests under test/func/java. These are end-to-end tests demonstrating how to use all aspects of the Phoenix JDBC driver. We also have some examples in the examples directory.
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