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Axion: Releases: 1.0 Milestone 3: Release Notes

Release 1.0 Milestone 3: Release Notes

There is no official 1.0 Milestone 3 release of Axion. This document is a draft.

To build 1.0 Milestone 3 see the instructions on how to obtain the source and build Axion.

This document describes the changes that have been made between the Milestone 2 and Milestone 3 releases of Axion.


  • Some potentially backwards incompatible changes were made to the way indices are managed. Namely:

    • Index names must now be unique across the entire database. (Previously they only had to be unique within their associated table.)

    • Index names are now forced into UPPER CASE, as table and sequence names always have been.

    This may pose problems for some operations on legacy databases that don't meet these new criteria.

    One simple solution to these problems is simply to remove the offending indices and recreate them. To do this, simply delete the index's data directory (i.e., DATABASENAME/TABLENAME/indices/INDEXNAME), then connect to the database and execute a new CREATE INDEX statement. (You may find the Axion console a convenient way of doing this.)

    Alternatively, you can manually correct the problem by renaming the index files. Each index must simply have a unique, UPPER CASE name. Go into your index directories (DATABASENAME/TABLENAME/indices/) and ensure that every reference to the old index name in a file or directory name is changed to the new name. For example, if you previously had an index on the table BAR named "ndx", that you want to change to "BAR_NDX", then you'll want to rename BAR/indices/ndx to BAR/indices/NDX, BAR/indices/ndx/ndx.data to BAR/indices/NDX/NDX.data, BAR/indices/ndx/ndx.type to BAR/indices/NDX/NDX.type, etc.

    If this change creates insurmountable problems for some users, we may be able to find a way to force-fit backwards compatibility on this point.

  • The format of the table meta-information file (DATABASENAME/TABLENAME/TABLENAME.meta) has changed. The 1.0 Milestone 3 engine will correctly read Milestone 0, Milestone 1 and Milestone 2 meta files, but Milestone 3 generated meta files are not accepted by previous versions of the engine.

Bugs Fixed

  • Restored support for SELECT without a FROM (for example select now()). Added tests to keep from dropping this support in the future.


  • Added support for IF NOT EXISTS clauses in CREATE TABLE, CREATE SEQUENCE and CREATE INDEX commands.

  • Added support for IF EXISTS clauses in DROP TABLE, DROP SEQUENCE and DROP INDEX commands.

  • Added support for DROP INDEX.

  • Minor changes required to support PersonalJava/J2ME, Applet and Java Web Start deployments.

  • Added support for column defaults, and hence autonumber columns (via sequences).

  • Added SEQUENCE.CURRVAL support (on top of our existing SEQUENCE.NEXTVAL).

Axion - Open Source Java Database Engine
$Id: release-notes.html,v 1.25 2007/11/15 15:09:27 rwald Exp $
Published 15 Nov 2007 at 3:04 PM GMT.