There's a few important differences between HBase versioning and ElephantDB versioning. The HBase versioning is more of a "buffer" that gives you a limited window to rollback when you make a mistake. As you said. if you overwrite too many times you can't recover.

The ElephantDB versions are totally independent from one another, whereas with HBase they're stored in the same index. The only tradeoff to storing more ElephantDB versions is using more space on the distributed filesystem. ElephantDB versions don't go away until you delete them, which lets you use whatever strategy you want to manage versions. For example, you may decide to keep one version each month, and every version for the past week. This lets you do analytics that looks at your data from long ago.