Lingual is true SQL for Cascading and Apache Hadoop.

Lingual includes JDBC Drivers, SQL command shell, and a catalog manager for creating schemas and tables.

Lingual is still under active development under the wip-1.0 branch. Thus all wip releases are made available from the files.concurrentinc.com domain. When Lingual hits 1.0 and beyond, final releases will be under files.cascading.org.

To use Lingual, there is no installation other than the optional command line utilities.

Lingual is based on the Cascading distributed processing engine and the Optiq SQL parser and rule engine.

See lingual-client/README.md for details on using the included command line utilities.

Lingual only supports SELECT and INSERT INTO statements, for example

`select count( distinct city ), sum( distinct age ) from sales.emps`

`insert into test.results select empno, name from sales.emps`

DDL statements like CREATE TABLE are unsupported at this time. See the Lingual Catalog tool for defining Schemas and Tables from the command line.

For more information, visit: http://www.cascading.org/lingual/

To install the Lingual command line tools, call:

> curl http://files.concurrentinc.com/lingual/1.0/lingual-client/install-lingual-client.sh | bash

This scripts downloads and installs the latest lingual shell script into ~/.lingual-client/ and updates any local .bashrc file.

To get the latest release, call:

> lingual selfupdate

You can optionally bypass the installation and just download the latest version of the Lingual client by calling:

> wget -i http://files.concurrentinc.com/lingual/1.0/lingual-client/latest.txt

Note, the install-lingual-client.sh file is also a valid Amazon EMR bootstrap action.

elastic-mapreduce \
  --create \
  --instance-group master --instance-count 1 --instance-type $MASTER_INSTANCE_TYPE \
  --instance-group core --instance-count $1 --instance-type $SLAVE_INSTANCE_TYPE \
  --bootstrap-action s3://files.cascading.org/sdk/2.1/install-cascading-sdk.sh \
  --bootstrap-action s3://files.concurrentinc.com/lingual/1.0/lingual-client/install-lingual-client.sh \
  --name "Cascading Cluster - $USER" \
  --key-pair $EMR_SSH_KEY_NAME \
  --alive

Lingual provides two JDBC Driver jars with self contained dependencies in the Conjars Maven repository.

The JDBC connection string is of the form jdbc:lingual:[platform], where [platform] is either local or hadoop.

Additional JDBC properties may be set using the form:

jdbc:lingual:[platform];[property]=[value];[property]=[value];...

Where the property keys are:

• catalog=[path] - the working directory where your .lingual workspace is kept
• schema=[name] - set the default schema name to use
• schemas=[path,path] - URI paths to the set of schema/tables to install in the catalog
• resultPath=[path] - temporary root path for result sets to be stored
• flowPlanPath=[path] - for debugging, print the corresponding Flow dot file here
• sqlPlanPath=[path] - for debugging, print the corresponding SQL plan file here

Platform is requried to help the driver distinguish between either backend when more than one JDBC Driver is in the CLASSPATH.

To pull either of these jars, the jdbc Maven classifier must be used.

For the local mode platform:

<dependency>
  <groupId>cascading</groupId>
  <artifactId>lingual-local</artifactId>
  <version>x.y.z</version>
  <classifier>jdbc</classifier>
</dependency>

For the hadoop mode platform:

<dependency>
  <groupId>cascading</groupId>
  <artifactId>lingual-hadoop</artifactId>
  <version>x.y.z</version>
  <classifier>jdbc</classifier>
</dependency>

Alternatively, pulling the default artifacts (without the classifier) will also pull any relevant dependencies as would be expected.

The best way to report an issue is to add a new test to SimpleSqlPlatformTest along with the expected result set and submit a pull request on GitHub.

Failing that, feel free to open an issue on the Cascading/Ligual project site or mail the mailing list.

Running:

> gradle idea

from the root of the project will create all IntelliJ project and module files, and retrieve all dependencies.