Changes for 1B vector benchmark

[tjake]

What is the issue

...

This is a draft to track changes

[github-actions[bot]]

Checklist before you submit for review

• [ ] Make sure there is a PR in the CNDB project updating the Converged Cassandra version
• [ ] Use NoSpamLogger for log lines that may appear frequently in the logs
• [ ] Verify test results on Butler
• [ ] Test coverage for new/modified code is > 80%
• [ ] Proper code formatting
• [ ] Proper title for each commit staring with the project-issue number, like CNDB-1234
• [ ] Each commit has a meaningful description
• [ ] Each commit is not very long and contains related changes
• [ ] Renames, moves and reformatting are in distinct commits
• [ ] All new files should contain the DataStax copyright header instead of the Apache License one