Use count to retrieve the number of rows of a table instead of reading all rows into memory and using List.size() / List.isEmpty().
The PurgeDatabaseTest failed when run against an IBM Informix database instance.
The Informix JDBC driver handles the long varchar columns like ACT_HI_DEC_IN.TEXT_ as JDBC-type CLOB if not explitcitly specified.
When using the generic approach (TableData) for reading data this gives an error for unknown reason. The regular access of the data through the spcific mapping (HistoricDecisionInputInstance) works fine, as here jdbcType is set to VARCHAR.
As the testcase is just interested in the fact if there are any rows or not in the table using the "select count" is sufficient. No need to read the data.