NIFI-3611: Added ability to set Transaction Isolation Level on Database connections for QueryDatabaseTable processor

[erichanson5]

NIFI-3611: Added ability to set Transaction Isolation Level on Database connections for QueryDatabaseTable processor

[ijokarumawak]

Thanks @erichanson5 for your contribution!
I concern about changing default behavior, so let's make the transaction isolation level optional.

[ijokarumawak]

Hi @erichanson5 Thanks for trying to incorporate the review comments. Now this PR has other unnecessary commits in it and the it looks not compiling well. Would you clean the commits?

I don't use merge when updating the local brach with the latest master, instead I use rebase.

If I'd recover from this state, I may use following steps:

1. Rename the current branch to different name, to clean-up the branch.
   e.g. git branch -m NIFI-3611-bk

2. Update the master branch to the latest. e.g.

   $ git checkout master
   # the name 'upstream' may be different, it's pointing github.com/apache/nifi.git
   $ git pull upstream master
   

3. Create new branch from the latest master.
   e.g. git checkout -b NIFI-3611

4. Port the 1st commit from the old branch.
   e.g. git cherry-pick 27d91507a00e095e212c1c96856806f53e868b82

   At this point, your new NIFI-3611 branch is synched with the latest master and has the 1st commit.

5. Apply the changes you wanted to make at the last commit. I recommend applying changes manually instead of cherry-picking here. At this point, your branch has the updates to incorporate review comments.

6. Push it to update this PR.
   e.g. git push -f origin NIFI-3611
   You need -f option to forcefully push the new commits

Hope this helps.

[erichanson5]

@ijokarumawak thanks for the assistance. I updated the branch

[patricker]

This sounds like a good general feature for a few SQL processors, like ExecuteSQL, maybe GenerateTableFetch.

I'm OK with limiting the scope to QDB for now, but what about putting the allowed values and property definition in AbstractDatabaseFetchProcessor so it's ready for use in other processors?

[erichanson5]

Thanks @patricker, I'll create another Jira ticket for that and work on it

[ijokarumawak]

The update LGTM, +1. Merging to master. Thanks @erichanson5!