Lookup Caches in
Informatica
|
Static cache
|
Dynamic cache
|
|
Shared cache
|
|
Persistent cache
|
Static
cache
Static Cache is same as a
Cached Lookup in which once a Cache is created the Integration Service always queries
the Cache instead of the Lookup Table.
In Static Cache when the Lookup
condition is true it return value from lookup table else returns Null or
Default value. In Static Cache the important thing is that you cannot insert or
update the cache.
Dynamic cache
In Dynamic Cache we can insert
or update rows in the cache when we pass the rows. The Integration Service
dynamically inserts or updates data in the lookup cache and passes the data to
the target. The dynamic cache is synchronized with the target
Shared cache
When we use shared Cache
Informatica server creates the cache memory for multiple lookup transformations
in the mapping and once the lookup is done for the first lookup then memory is
released and use that memory used by the other look up transformation.
We can share the lookup cache
between multiple transformations. Unnamed cache is shared between
transformations in the same mapping and named cache between transformations in
the same or different mappings.
Persistent
cache
If we use Persistent cache
Informatica server processes a lookup transformation and saves the lookup cache
files and reuses them the next time. The Integration Service saves or deletes
lookup cache files after a successful session run based on whether the Lookup
cache is checked as persistent or not
In order to make a Lookup Cache
as Persistent cache you need to make the following changes
- Lookup cache persistent: Needs to be checked
- Cache File Name Prefix: Enter the Named Persistent cache file name
- Re-cache from lookup source: Needs to be checked
Recache from database
If the persistent cache is not
synchronized with the lookup table you can configure the lookup transformation
to rebuild the lookup cache.
very useful and nice
ReplyDeleteclean n clear
ReplyDeletethnks
ReplyDeleteNice and easy to understand
ReplyDeleteVery good information however screen shot of change mode of look up cache might me more useful.
ReplyDeleteVery clearly mentioned
ReplyDelete