asqldb

ASQLDB is an SQL/MDA implementation based on HSQLDB and rasdaman. The SQL/MDA Part 15 of ISO SQL adds advanced query support for multidimensional arrays.

Getting started

• Assuming you have downloaded the ASQLDB sources to $ASQLDB_HOME:

• cd $ASQLDB_HOME

• If setting up for the first time, please run:

• mkdir -p /var/hsqldb

• chown $USER: /var/hsqldb (assuming you run ASQLDB with $USER)

• Configure the rasdaman connection:

• mkdir -p $HOME/.asqldb

• cp sample/rasdaman.properties $HOME/.asqldb/

• editor $HOME/.asqldb/rasdaman.properties (to adapt it)

• Configure the ASQLDB connection:

• mkdir -p $HOME/.asqldb

• cp sample/sqltool.rc $HOME/.asqldb/

• editor $HOME/.asqldb/sqltool.rc (to adapt it)

GUI client

The Database Manager is a GUI client for ASQLDB. To start, go to the build directory and build lib/hsqldb.jar:

• cd build && ant hsqldb

The GUI manager can be started with the bin/sqlgui bash script (--help for more information). You can link the script to /usr/bin for convenience sudo ln -s $ASQLDB_HOME/bin/sqlgui /usr/bin, and then use it simply with sqlgui.

The sqlgui script is simply a wrapper that executes the hsqldb.jar; you can manually run this for better control:

• java -cp lib/hsqldb.jar:lib/rasj.jar org.hsqldb.util.DatabaseManagerSwing (--help for more information)
• check the Utilities documentation for full documentation on the Database Manager: doc/util-guide/index.html

Command-line client

SqlTool is a JDBC client that allows executing queries from the command line. To start build the latest SqlTool as lib/sqltool.jar:

• cd build && ant sqltool

To run it:

• java -jar lib/sqltool.jar

For example, executing the SQL commands in file setup.sql with the personal "urlid" from the default sqltool.rc could be done with:

java -jar lib/sqltool.jar personal setup.sql

More information can be found at:

• java -jar lib/sqltool.jar --help
• the Utilities documentation, doc/util-guide/index.html

Example

Suppose we have a table in ASQLDB:

CREATE TABLE Arrays (
  id INTEGER PRIMARY KEY,
  acquired DATE,
  a INTEGER MDARRAY [x]
);

In Arrays we could insert the following data for example, including a sample 1D array of three elements:

INSERT INTO Arrays
VALUES (1, '2014-01-22', MDARRAY[x(0:2)] [0,1,2]);

The MDARRAY is automatically inserted in rasdaman, while HSQLDB stores its unique object identifier for reference. In SELECT queries then we can do advanced array processing on the array column, and even combine it with other non-array columns, e.g.

SELECT acquired, avg_cells(a[0:1]) * id
FROM Arrays

The rasql syntax (http://rasdaman.org/ for more details) is mostly supported as is, with subtle keyword differences, like MDARRAY instead of MARRAY, and AGGREGATE instead of CONDENSE.

Automated tests

To run the automated JUnit tests:

• cd build
• ant run-asqldb-tests

This will produce summary including number of passed/failed tests in the terminal, as well as in ../run-asqldb-tests.txt

Todo

• Full DML support (UPDATES missing at the moment)
• Extend documentation with Array SQL specification and examples
• Adapt JDBC driver for multidimensional array results