What is "In-Memory ENgine" in qlikview ?? How does it helps qlikview performance wise??

[nikhilgarg]

Hey,

What is "In-Memory ENgine" in qlikview ?? How does it helps qlikview performance wise??

tHanks

[hic]

First, all data is loaded into primary memory for fast access.

Secondly, calculations are made on-demand, i.e. the developer that creates the data model does not need to know exactly which questions the user will ask or which formulas that need to be calculated. As long as the data model is logical and coherent, any calculation can be made.

As a result, calculations are made fast, and change requests can be executed immediately. There is (in most cases) no need to change the data model. This is in sharp contrast to many other tools on the market, where a change request can mean weeks of work.

HIC

See also

Symbol Tables and Bit-Stuffed Pointers

Colors, States and State vectors

It’s all Aggregations

[nikhilgarg]

Hey,

THanks it helps but what i really want to know is :what do you mean by "in memory engine".

[hic]

Well, it is basically the above. It is an engine that can calculate almost any formula on a specific data model. And it operates in memory, without using the disk.

HIC

[nikhilgarg]

OHk , Thannks HIC and if i am not wrong this in memory engine is not visible to us  , ryt ?

[hic]

Depends on what you mean "visible"...  It is certainly not a window or an object that you can see on the screen.

Instead it is the code in the program that evaluates what to show when you click: What should be grayed out? Which numbers should be shown in the pivot table? You could say that the program itself is the engine, with a number of visualization objects on top of it.

HIC

[nikhilgarg]

Hey,

Thanks it helps and this code of in memory engine is visible to QLIkTech , ryt ?

[sspe]

You should basically just see the "InMemory" technonlogy as a different way of storing the data you are working with (In memory vs. on disk).

I don't think it makes sense to talk about if the data in memory is visible or not - it's visible in the sense that you can see it and use it in your application but you can't easily look at the raw data (and I can't see any reason for why you should). As such it's not any different from many other applications that just stores the data on disk - these data are not visible either. E.g. SQL Server stores the data in MDF (and LDF) files on disk, but eventhough you can see the actually file on your disk doesn't mean that you can see the data in the files (...unless you know how to use the tools and commands to do it).

From a performance perspective, it will in most cases be much faster to work In Memory compared to reading the data from a disk since there are no physical operation involved in finding the data.

/Steen

[nikhilgarg]

Thanks .

[vvvvvvizard]

This engine is used to operate qlikview's in memory architecture  . If Qlikview retrieved data from disk , this would be very slow , Using the In memory engine qlikview can retrieve stuff 100 thousand times faster , as memory is many 100's thousands faster than disk