Document TCK usage of database tables including the fact that the tests are idempotent (i.e. can be re-run)

Nobody has claimed this yet.

It should be more clearly that you do not need to cleanup the TCK application DB tables (NUMBER, INVENTORY, ORDERS) between executions.

I believe all the tests using them are located in the TransactionTests.java test class, which all execute jobs with initial "setup" steps that initialize the DB tables appropriately. In other words, the tests clean up at the beginning of the execution (rather than at the end of the execution).

But it's not extremely clear that this is the case, and so I hesitate to put it in writing, even though we are basically assuming this is the case (or else we would need additional instructions to drop/recreate tables between executions).

Start by reviewing TransactionTests.java and the initial setup steps for the NUMBER, INVENTORY, and ORDERS tables. Confirm that setup makes repeated executions safe, then document that the TCK application database tables do not need cleanup between runs; the documentation is done when this behavior and its scope are clear.

Written by the indexing model from the issue text.