why lookup transformation is passive?
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why lookup transformation is passive?
why lookup transformation is passive?
Look up transformation is Passive because for each input row must get one output value (whether it is look up value or null).
what is sorogate key and production key in informatica.
How manay types of transformation in informatica and what are they.
What is STAR schema and snowflake schems.who is better.and what is the difference between them.
what is the latest version of informatica.
Informatica 8.1
[QUOTE=sunil8816;17559]why lookup transformation is passive?[/QUOTE]
the lookup transf.. is used to look up data in relational tables, views e.t.c so here there is no change in the number of rows while data is flowing from source to target. so it is a passive transf...
please correct me if i am mistaken...
thks
thanesh
it is an [B]system generated [/B]key,which is uniquily identified by either entity or the object
can any one say what is an production key
[B]star scheema[/B]:one fact table is surrounded by four dimension tables,the data in this is denormalised data, all facts are numeric, but not all numerics are the facts . the numeric with KPI(Key Performance Indicter) is only the fact
[B]use[/B]: if we want to calculate the total table report it is very usefull
[B]snowflake scheema[/B][B]:[/B]fact table is divided into number of dimension tables getting the data is nomalised, and it has a [B][I]parenr_child key relation ship[/I][/B] also
[B]use[/B]:if we want to calculate each table report,it is usefull
Look-up transformation just does look-up on the source,target table etc..Look-up is passive as it doesnot change the no.of rows passing through it.
Star schema - A centralized fact Table with or without measures connected to corresponding dimension tables in such a way that the topology appears like a star.its basically based on denormalized tables.
Snow schema in dwh env uses third normal form rather than star schema which uses a denornalized structure.Snowflake schemas normalize dimensions to eliminate redundancy.that's instead of One large table.
Ex: Location Dimension in star schema might be normalized into Locationa dn city tables in Snow flake schema.
what is multi-tier data warehouse strategy for what type of projects it is implemented.
[QUOTE=manaskumarpatra;26596]How manay types of transformation in informatica and what are they.[/QUOTE]
There are more then 20 transformations in informatica
Those are (source qualifier,filter,expression,aggregator,joiner,sequence generator,rank,sorter,stored procedure,lookup,union,router,update strategy,transaction control)