The SAP HANA database allows you to create your tables in Row or Column Store mode. In this blog, I will demonstrate that each method has its advantages and disadvantages and should be used for specific cases. Thanks to two kind of tests, I will show you that the Row Store mode should be used for simple SELECT SQL queries,…
Let’s continue with this series about inserting 1M rows and let’s perform the same test with a new variation by using SQL Server In-Memory features. For this blog post, I will still use a minimal configuration that consists of only 1 virtual hyper-V machine with 1 processor, 512MB of memory. In addition my storage includes VHDx disks placed on 2…
By Franck Pachot . Oracle In-Memory option is for reporting. Oracle has chosen an hybrid approach: maintain the In-Memory Column Store in addition of the buffer cache. Dont’ forget our In-Memory event, but for the moment, let’s try the 1M row insert when the target table is IN MEMORY. 12c I’ve done the previous variations on 11g because I wanted…
Since SQL Server 2014 CTP2, Microsoft has introduced a new kind of index which is the Range index. We have now two ways for indexing an In-Memory table: using either an Hash index or a Range index. These two indexes are slightly different. In fact, a Hash index is a set of buckets, 8-bytes memory pointers, which points to the…
A customer asks me, how to know if In-Memory Feature is supported by my SQL Server server? An easy way is to check the edition, version etc. but now, you have directly a property for that. On msdn here, you find all property that you can search with the T-SQL Command: SERVERPROPERTY But if you try to run through all…
By Franck Pachot . In-Memory Column Store is amazing. It brings very good performance to full table scans. I’t easy: just ‘flip a switch’ and you accelerate all reporting queries on your table, without thinking about what to index and how. But in this post, I would like to warn you about the consequences when you just flip that switch.…
Last week I gave a workshop about SQL Server 2014 and the new features. The first day we worked on new In-memory OLTP and different topics such as the new internal storage, the new transaction processing behavior or the new checkpointing process. During this day, one of the attendees asked me about the memory management with In-Memory OLTP feature. It…
By Franck Pachot . When an Oracle Database spends a high percentage of its DB time in User I/O, I usually check the wait event histograms in order to see if the storage system is working well. But today, with storage going to SSD, most I/O are less than 1 milliseconds and we have no details about those wait times.…
By Franck Pachot . It’s just a patchset. The delivery that is there to stabilize a release with all the bug fixes. But it comes with a lot of new features as well. And not only the one that has been advertised as the future of the database. It’s a huge release. Let’s have a look at what’s new. First,…
By Franck Pachot . Oracle has announced a big feature that should come in the next 12c patch set: the In-Memory option. It will soon be in beta version, so nothing will be published about it until it comes to production. Before that phase, I’m going to explain what we can expect from that feature, besides the ‘In-Memory’,’columnar storage’, and…
Some customers or colleagues recently asked me about the SQL Server concept xVelocity and in particular the SQL Server 2014 feature new xVelocity memory optimized columnstore index. So I decided to write a few words on the dbi services blog. What is xVelocity? Introduced in SQL Server 2012, xVelocity is composed of two features: xVelocity in-memory analytics engine xVelocity memory-optimized…
One of the best new functionalities of Microsoft SQL Server 2014 is the In-Memory part, which gives you the possibility to load tables and also Stored Procedures in-memory for a very fast response time. The Community Technology Preview 2 from Microsoft SQL Server 2014 went out some days ago with two new Advisors. These Advisors will help you manage the…
