I keep getting questions around what core features are missing in Standard Edition of SQL Server,and why there is a need to install Enterprise edition for business critical systems.Here are my top features which are missing in standard edition –

Scale limits

Memory – Standard only supports 128 GB memory.

Memory is relatively cheap now,and I can’t think of any reason why someone can’t have more memory on business critical servers.

CPU cores Limited to lesser of 4 Sockets or 16 cores.

High Availability

AlwaysOn Failover Cluster Instances – Possible but only 2 nodes supported.

AlwaysOn Availability Groups*.

*AG is the future of HA/DR strategy within SQL Server and because of great demand, Microsoft will be allowing AG in standard edition of SQL 2016, however it will only support 2 nodes. Support of just 2 nodes is not sufficient for a solid HA/DR architecture.

Online page and file restore.

Page restores can come handy if you have to deal with corruption of a very large database and corruption is only for very few pages.

Online indexing.

You don’t really want to lock down the table while doing index maintenance right? Online index operations are key to maintain the uptime of the database.

Online schema change.

Hot Add Memory and CPU.

Database Snapshots.

Scalability and performance

Table and index partitioning.

Database size is increasing like never before and 3-5 TB DBs are very common these days. Maintaining these DBs without a partitioning strategy can be a very bad idea.

Data compression.

One of the most ignored features in SQL Server. Compression can be really helpful to save some space without much overhead.

Resource Governor.

IO Resource Governance.

In-Memory OLTP.

In Memory OLTP might be having lot of restrictions today, however things are going to change soon. I’m pretty sure that there will be multiple use cases when this feature is stable.

Memory optimized columnstore indexes.

Column store indexes dramatically improves DW workload performance and this feature will get more and more enhancements in the future.

Security

Transparent database encryption.

Conclusion – 

Business critical systems needs to be treated as critical as there is a potential risk of losing revenue if these systems are not highly available and uptime requirements are not met.Performance is also a key factor, and SQL Server standard edition is not the right edition for these requirements.