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Author Topic: Dynamic Cache..? It's purpose...?  (Read 2652 times)
Raj2007
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« on: June 27, 2007, 07:46:54 pm »

Hi friends..!

What is the concept of Dynamic Cache?
How it differs from Static cache?
In Inforamtica, when we will prefer a Dynamic cahce rather than Static cache?
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Sipra
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« Reply #1 on: June 28, 2007, 10:33:53 am »
Dynamic means -

For Eg - If you are using a LookUp Tranasformation and Lookup cache for a particular table.

   So this Lookup cache will read the table at a time and will keep that data in the memory in the form of lookup cache. But this is generally under assumption that the lookup table is not getting changed during that time.

   Let if the lookup table values getting changed during that time, this Lookup cache will not hold the recent values.

So instead of standard Lookup cache (i.e., Static cache) we will use Dynamic Cache in this case, which holds the recent values.
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Sipra
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« Reply #2 on: July 06, 2007, 12:33:50 pm »

Can you please define the Persistent Cache in the same way?

Whats the difference in between three of these - Static, Dynamic and Persistent ??
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balambigai85
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« Reply #3 on: November 20, 2009, 05:19:21 pm »
Lookup data is stored in the form of cache.
We can decide whether the cache has to be present even after the session run or the cache no longer needed after the session run.
If persistent cache is enabled, then cache is retained and can be reused.

If the lookup data does not change between multiple session runs, we can set the cache to be persistent
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priya
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« Reply #4 on: March 12, 2010, 10:04:52 am »
The below cache data's will be deleted after the session run

Static cache- standard data.

Dynamic Cache- recent data.

The persistant cache data wil not be deleted even after the session run

Persistant Cache - reusable data.
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priya
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« Reply #5 on: March 17, 2010, 03:11:41 pm »
Hi,

If you choose the dynamic cache then the look up will pick the latest data from the table.

Static cache will be prefered at the situations where the look up needs to load the standard data.

Both dynamic cache and static cache buffers will be deleted after loading the data into the target table in the session/mapping. Whereas in the persistant cache the buffer will not be deleted after the session run.



Regards,
P
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shanilr
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« Reply #6 on: May 18, 2010, 12:18:03 pm »
Hi,

The Integration Service builds the cache when it processes the first lookup request.A lookup cache does not change once it is built. But what if the underlying data on the lookup table changes once the cache is built. The answer is use Dynamic Cache.

You can use Persistent cache when you know that the data in your lookup table changes very rarely. for example let's say that you have a dimension called Store. As you know that the business does not add new stores to their business very frequently and this can be a candidate for persistent cache. If the data in the table changes sometime later you can override the session property to re-cache the lookups from databsae.

You use Static Cache when the data in the lookup table can change between session. The integration service builds the cache once it process the first lookup request. For the subsequent lookup request it will lookup in the cache rather than looking up from the source. Customer dimension can be a good candidate for static cache since the data keeps changing on a daily basis.

Use dynamic cache when you are doing lookup on the table that is also used as target. Since the target keeps changing during the session run you will get a better control on hadnling the incoming data by actually be able to lookup on the updated target table. This is very useful when you are going for SCD.


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