SQL data compression for Dynamics AX 2012 (Part 2)

It has been a while since I have touched up on SQL data compression in part 1 on my blog. It is time to re-visit the topic.

SQL data compression for Dynamics AX 2012 (Part 1)

Since that post Microsoft has published an excellent series of articles on how to apply compression within AX, or directly on SQL Server. It is a must-read blog post for everyone, so start there:

https://blogs.msdn.microsoft.com/axinthefield/sql-server-data-compression-for-dynamics-ax-0-blog-series/

Since JJ Food Service has a very large database, we have started applying compression to Production AX. Our SalesLine and CustInvoiceTrans has been between 250-350 GB size each! Our approach was to apply compression before a maintenance window using the Enterprise Edition license of SQL Server in ONLINE mode and using TempDB sorting, so it was running during business hours only adding a slight overhead to the system (mostly as disk I/O). It took 4 and 6 hours respectively, and space saving was more than 75% which is excellent.

Once the compression has finished and we were about to begin our regular Friday night maintenance, once the AX AOS, reporting and web services were all down, we could run the post-compression SQL script provided by Microsoft to populate the SQLStorage table. This is required for the Data dictionary synchronization step to recognize compressed indexes, so it would not drop and recreate them uncompressed.

Eventually we will consider compressing our whole database for Page level. The reason being is that Dynamics 365 for Finance and Operations, Enterprise edition in the background uses full page compression for the whole AX database. If you would like to use the upgrade scripts from 2012, even the documentation mentions that compression is a pre-requisite step:

https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/migration-upgrade/prepare-data-upgrade

As a result we have seen great performance boost for the tables involved and much lower numbers in the slow performing SQL statements, since more data could be kept in the SQL memory buffer.

DAXRunBase / 2018-02-27 / AX 2012, Dynamics 365 for Finance and Operations / 0 Comments

AX database tuning and maintenance – How to keep it healthy

It is very crucial for your environment to audit, evaluate, then carry out an AX database tuning and maintenance task regularly in order to keep Microsoft Dynamics AX in a good shape.

There are many areas which are frequently being overlooked by partners and customers, for which Bertrand from the Microsoft PFE team has written an excellent summary that you should read here:

https://blogs.msdn.microsoft.com/axinthefield/top-10-issues-discovered-from-dynamics-ax-health-check/.

Many of these configurations are very important to keep your environment healthy from day 1. Often overlooked settings include for example the Index fill factor. It causes fragmentation as records are getting created and updated in your database, resulting in slower statement execution times and even timeouts, which is very bad and has been discussed in this post:

Improve AX performace by fixing bad Query plans

If you’ve got very large DBs like we have, you could be safe with setting 90% then doing an index rebuild to not bloat your DB size by too much. Other than that the MS recommendation is between 80-95%.

Having the correct SQL Trace Flags are also equally important, you could read about them again on the PFE blog. We are running 1117, 1118, 1224, 2371 and 4199. Also it is recommended to use the dataAreaIdLiteral AX setting if you have a multi-company environment, to avoid parameter sniffing.

(more…)

DAXRunBase / 2016-05-11 / AX 2012 / 1 Comment