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Impact on data retrieval by creating vDB

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  • 1.  Impact on data retrieval by creating vDB

    Posted 02-27-2018 05:24:00 PM
    Hi All,

    I understand that we can create outlines on the vDB just as we would on a physical DB, however, since the storage is now no longer available locally, does it impact how data is retrieved ?

    In other words, can i still create outlines and test on the vDB before i actually put this on the PROD env that is non-virtualized ? I understand that the quantitative results on the vDB may not be representative of PROD as the vDB in test may not be as performant, but can i still rely on the qualitative part, i.e, test between the plans to see which is better ?

  • 2.  RE: Impact on data retrieval by creating vDB
    Best Answer

    Posted 02-27-2018 07:04:00 PM
    Hi Mayank,
    In my opinion this is a good use case.  Whilst the actual performance will be dependent upon the infrastructure constraints of the architecture, the relative performance based on the different outlines you create should provide some comparative information.  The actual performance will be different from the physical database due to the additional network hop passing through the Delphix Engine, the overall network bandwidth from the engine to the target server plus the fact that Delphix Engine provides an ARC Cache which can dramatically improve performance for batch-like workloads, where there is a potential for a high cache hit ratio.  you could even create separate branches (versions) and run different workloads through each, without the need of a DBA, using self service or (better still) automate such testing through the API.  This would be a good way to monitor different outlines over time, over different workload characteristics.
    I don't know of any customers who have done this and would love to hear more feedback here on the community from anyone who has tried this out.

  • 3.  RE: Impact on data retrieval by creating vDB
    Best Answer

    Posted 02-27-2018 08:46:00 PM
    This is a good use case.  You can refresh your VDB and test new SQL Plans, Outlines, Hints, Statistics, etc.  If you're fetching fewer blocks on your VDB with your new approach, this should translate to fewer blocks (and better performance) on your Production system.  I've worked with customers who have done this.

  • 4.  RE: Impact on data retrieval by creating vDB
    Best Answer

    Posted 02-28-2018 10:13:00 AM
    Thanks guys ! We will give it a try