Steps to reproduce:

1. add a job to the ACT_RU_JOB database table
2. create ACT_IDX_JOB_HANDLER index

Problem:
The following warning is emitted:

Code: 1945 SQL State: 01000 — Warning! The maximum key length is 900 bytes. The index 'ACT_IDX_JOB_HANDLER' has maximum length of 8510 bytes. For some combination of large values, the insert/update operation will fail.

Hint:
The warning is not emitted when the table ACT_RU_JOB is empty and the index is created.