ejbTimer feature with DashDB in bluemix

Question

If you choose to use ejbTimer feature with DashDB in Bluemix, you end up with errors. We've analyzed the problem and came up with the analysis that ejbTimer feature creates a set of tables (WLPTASK, WLPPART, WLPPROP) in its create phase. These assume 'ORGANIZE BY COLUMN' (default on DashDB).

As a workaround, we found out that if we used the feature in standalone (non Cloud) Liberty server, let that create the tables. Take the DDLs from that and adjust them with 'ORGANIZE BY ROW'. Manually create the tables in DashDB. Then using the feature in Bluemix does not need to create tables and works with these manually created tables.

I assume this is not expected behavior - is there a fix for it ?

Answer 1

What you have done to work around this issue is good. The reason why this doesn't work out of the box is that Liberty uses EclipseLink (ECL) to create the tables for EJB timers and ECL doesn't have full support for DashDB.

ECL supports all compliant SQL and JDBC drivers. However, ECL only supports schema generation for a select set of databases. Unfortunately, DashDB is not on the list of databases that ECL supports schema generation for.

I suggest that you continue to use this workaround of manually editing the DDL generated for Derby, and in the meantime open a Request For Enhancement (should take 10 mins or less) for IBM to add DashDB schema generation support to ECL.