Hi Tom,

I guess we could say that the problem with the database and application world is that like most worlds, it isn’t perfect. As such, you are correct by saying that an application that during the day behaves as an OLTP type, at night shifts to a batch/DSS like behavior. This happens due to natural business cycles where the operational systems’ data need to produce summary reports, run backups, or the data extracted, cleansed and sent to other systems such as Data Warehouses (DW), Business Intelligence (BI), OLAP, etc. The result is that the border between OLTP and DSS softens. When today I ask DBAs if their database is an OLTP or DSS the answer is most often – both!

There is another trend that soften the boundary, which is in-memory databases (IMDB). Being that IMDBs are very fast, they are often positioned as a single repository of data for both OLTP and DSS alike. I’m not a great believer in this trend since a true BI or DW indeed shows a DSS workload behavior (large data scans, sequential nature and so on), however, their *content* is not the same as the operational systems. It is often an aggregation and summary of data from multiple operational systems and requires some cleansing first (often data in different operational systems isn’t inserted in the same way, may include missing records, too detailed, etc.).

Regarding your question of treating transaction logs as DSS my take is that although like you said the logs are typically sequential write (and reads for archiving), we tend to use the terms DSS or OLTP for a whole database or application, and more often to the nature of how the data is being accessed, not so much the transaction logs. Still, you’re right if you only consider the access pattern per storage group.

Regarding eNAS on VMAX3/AF, we don’t necessarily distinguish between FC, iSCSI (block storage), or eNAS (file storage) as far as application type and leave it to the customer to decide how they want to access their data. You can find a white paper on VMAX3 with SQL Server and eNAS here.

To actually go back to what you asked about – “I was trying to identify examples of host apps/services that fall under the workload type of DSS.” I’m not an expert in this space to provide a list, however, if you’re interested, one approach is looking at Gartner’s “Magic Quadrant” (example here, just click on the image to magnify. The full report goes into more details though cost money). Or google the subject (here is one result I found). Since I didn’t read closely either of these two links, I just bring them as examples and not advocating their content However, note how they usually point to an application and no a database. If you dig deeper, some of these application use the same databases OLTP systems may use, and other have their own.




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