It’s quite interesting that Microsoft’s SQL Server 2014 release has a number of In Memory performance optimisation features.  The clock speeds of CPUs have not significantly increased over the last few years  but memory has become relativity cheap and the 64 bit Windows platforms now provide substantial scope to run high memory footprints.

Therefore it make sense for Microsoft to leverage memory to gain significant performance improvements in their SQL Server product line.  The memory related performance features include :-

• In-Memory OLTP – improve the performance of some OLTP applications from 5x to 30x
• Updatable columnar Indexes – to improve the performance of Data Warehouse queries
• Buffer Pool Extension – not really an In Memory feature but still extends Buffer Pool memory to fast IO SSD devices that act like a L2 cache for SQL Server
• PowerPivot – memory compression for BI analytics in Excel
• Tabular Model in Analysis Services – memory compression for larger data sets used in BI analytics

However, there have been calls for Microsoft to remove the ridiculous memory restriction of SQL Server Standard edition (currently 64 GB). While they are at it they should add a two node AlwaysON Availability Group feature to the Standard Edition, but that’s a gripe for another time.

Here’s an article describing the SQL Server Magazine’s take on the In Memory Revolution (here)