As of version 3.9.0 all future indexes use 64-bit hashes instead of 32-bit hashes. Event Store automatically transitions your indexes from 32-bit to 64-bit by writing all new indexes as 64-bit indexes during the merge process.
If you prefer to use only 64-bit indexes immediately you can force this change. For a small database, delete the index folder in your database folder, and let it rebuild (this might take a while)
If you have a large database, or it's stored in remote storage, and you can't lose downtime, you can run this operation offline on another node with the following steps:
- Take a back up.
- Restore the backup to fast local disks.
- Delete the index folder from back up.
- Run Event Store with a cluster size 3 to prevent other writes. It will rebuild the index.
- Restore the index back to a node (index folder).
- Let Event Store catch up from master.
- Repeat the restore for other nodes.
For other indices, your index will change to 64-bit due to the merging process that occurs over time.