I was fortunate to catch the Developer Chalk Talk about Hekaton at PASS Summit 2012. For those not familiar, Hekaton is a new in-memory technology being integrated with SQL Server that is able to radically improve performance. Here are some of the things I caught from the talk with the developers of Hekaton.
- The teams goal was a 100x performance increase over normal tables, hence the name Hekaton.
- Hekaton is not just putting tables into memory. It is a completely redesigned way of thinking about tables.
- While you could put an entire database in Hekaton, that is not exactly the way Microsoft engineers thought it would be used. Probable use case’s from Microsoft are that specific tables are only brought in to Hekaton, specifically those with problems with locking and latching.
- There are no locking and latching in Hekaton tables.
- Data is persisted in Hekaton tables.
- You do not want to under allocate space in Hekaton. Microsoft didn’t exactly say what would happen if you wrote more data than space in Hekaton from the tone it didn’t seem pretty. I got the vibe that it may crash.
- You can also recompile some stored procedures to further increase performance. Apparently, they are compiling the stored procedures to machine code to get them to run faster. This may not work on all stored procedures. This is also optional, you do not have to do this.
- Only hash indexes are supported in Hekaton at this time.
- At this time, only whole tables are supported in Hekaton. No partions.
- Hekaton will be in SQL Server Enterprise edition when it comes out.
The guys were very good at answering questions. They made it clear that not all features of traditional tables will be available in the first release. They are working with customers to see what exactly should be available in the first release. They couldn’t answer all the questions as it was supposed to only be a 30 minute chat (I had to leave after 45) but they did say they would put out a paper about some of the more detailed technical items.
To clarify, Hekaton is not out yet. It will be released with the next version of SQL Server. The guys claimed to see 2x – 50x improvement with Hekaton tables in their labs but it’s still very early.