# Release Highlights

This release improves support for OLTP-style (highly-selective) queries on columnstores, High Availability, and Disaster Recovery.

## Support for Operational Applications

* As part of the SingleStore initiative, enhanced the columnstore to enable transactional workloads to be processed more efficiently. These enhancements include support for single-column unique hash keys on columnstores and [fast joins on columnstores, where there is a highly selective filter on one table in the join](https://docs.singlestore.com/db/v9.1/create-a-database/columnstore/highly-selective-joins.md).
* Added the `INTO` option to the `SELECT` command, which can be used in procedural SQL. SELECT INTO allows you to select the columns in a one-row resultset into a list of variables, making your code more concise.

## High Availability and Disaster Recovery

* During replication, if your primary cluster fails, you can reverse replication from your secondary cluster to your primary cluster to quickly **failback to the primary cluster**.
* In High Availability mode, you can now use the l**load\_balanced** setting of the engine variable `leaf_failover_fanout` to evenly distribute a leaf L’s replica partitions across a set of leaves in the cluster. This is an alternative to the `paired` setting, where all of leaf L’s replica partitions reside on one paired leaf. Using `load_balanced` allows you, if leaf L fails, to distribute its failed-over workload to the set of leaves instead of just one, balancing the load.

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Modified at: July 12, 2022

Source: [/db/v9.1/release-notes/singlestore-memsql/7-1-release-notes/release-highlights/](https://docs.singlestore.com/db/v9.1/release-notes/singlestore-memsql/7-1-release-notes/release-highlights/)

(An index of the documentation is available at /llms.txt)