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how it works with the in-memory?

Hi all,

          Iam very new to this qlikview software. I have some queries regarding this.

1)How it works with the in-memory.?

2)when will be the data loaded into RAM.?

3)when will it create the associative model and how the hierarchies will be done?

4)As RAM is a volatile memory do we need to load the data every tym when the system was off or is there any alternative approach to overcome this?

please help me guys....

Thanks in advance....

21 Replies
Not applicable

how it works with the in-memory?

Hi!

1, not sure what you looking for - a technical explanation?

2, During execution of the load script.

3a, During the execution of the load script b) automatically through naming the fields.

4a, Power off and you need to reload, yes. b) Server cluster (power off both servers and you still need to reload...)

Download a free demo and try it, you won't regret that.

gandalfgray
Valued Contributor

how it works with the in-memory?

Hi

"reload" is a QlikView term for when data is brought in to a qvw application using QV:s load script.

When you are reloading you can see memory consumption rise and fall, according to what you do in the load script

After a "reload" you can save the application, and when you close it all memory used by that application will be released.

The next time you open that application you will also load into memory all data exactly as it was when you saved the application. (no qlikview reload needed)

so I would like to add to Thomas answers:

2) ...or when opening a saved qvw application

4) You do not have to reload the data for an application if the application is saved before power off, you just have to open the application

Not applicable

how it works with the in-memory?

thank you thomas

Not applicable

Re: how it works with the in-memory?

what type of languages or scripts we can use in the script editor apart from sql

Not applicable

Re: how it works with the in-memory?

thank you gandalf. will get in touch for further explanations from you

Not applicable

Re: how it works with the in-memory?

what type of languages or scripts we can use in the script editor apart from sql like jscript or vb etc..

gandalfgray
Valued Contributor

how it works with the in-memory?

The only place you use sql in  QlikView load script is when you are fetching data from an sql database.

Otherwise you use QlikViews proprietary scripting language (I've never heard a name for it...)

It is defined and explained in the QlikView Reference Manual, and also in the help that's included in QlikView.

Then there is also a "Macro script" part which you can program either in VBscript or Jscript.

For basic applications you will not need macro scripting at all.

MVP
MVP

Re: how it works with the in-memory?

  1. http://www.dbms2.com/2010/06/12/the-underlying-technology-of-qlikview/
  2. The data is loaded from the source when you do a load.  For users, the file is loaded into RAM when they open the file, just like any other file.  In a client server environment, you can preload files into RAM as well.  QlikView also caches data, I believe even for files you have closed.
  3. To clarify an earlier answer, the associations are made at the END of the load script.  Until then, as best I can tell, QlikView makes no attempt to associate your tables.  This seems logical, as until then, you cannot be certain of any associations.
  4. If you turn the computer off, you no longer have the document in memory.  To put it back in memory, you need to boot the computer and open the document.  There's nothing special about QlikView files in this regard.  They're just files.

"what type of languages or scripts we can use in the script editor apart from sql like jscript or vb etc."

QlikView Script.  It has its own scripting language.  I agree with GandalfGray that you won't need to code macros for basic applications.

Luminary
Luminary

Re: how it works with the in-memory?

Hi shantheguy ,

Please see below for some information on the load process...

The data records are read into the memory, so that all the processing of data may be done through memory. I am sure you know this bit. QlikView treats all the data as Data Element Type (Columns / Fields) and Data Element Values (Values / Records). So each different data element value of each data element type is assigned a binary code and the data records are stored in binary-coded form and they are also sorted. By using the binary coding, very quick searches can be done on the tables. Also, QlikView removes the redundant information information and reduces the amount of data. However, the redundant information in stored as seperately with the frequencies for each unique data element value and across each data element type. When user makes a selection on data element values then the implied selection (possible values) are kept track seperately to present them to the user. By this process QlikView can perform rapid linear searches.

I understand this is not in detail but just a quick overview. I hope this helps!

Good luck!

Cheers - DV

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