Informatica Data Warehousing

Maping parameter represents a constant value that You can define before running a session.A mapping parameter retains the same value throughout the entire session.

When you use the maping parameter ,U declare and use the parameter in a maping or maplet.Then define the value of parameter in a parameter file for the session.

Unlike a mapping parameter,a maping variable represents a value that can change throughout the session.The informatica server saves the value of maping variable to the

repository at the end of session run and uses that value next time you run the session.

When you edit,schedule the sesion each time,informatica server directly communicates the repository to check whether or not the session and users are valid.All the metadata of sessions and mappings will be stored in repository.

repository always stores the meta data which stores all informations about trasformations, sessions, mappings,

scheduling and user validation of the process.

Target Types are File, Relational and ERP.

Two ways:-

1.Drag the port from another transforamtion

2.Click the add buttion on the ports tab.

Reusable transformations can be used in multiple mappings.When you need to incorporate this transformation into maping, U add an instance of it to maping.Later if you change the definition of the transformation ,all instances of it inherit the changes.Since the instance of reusable transforamation is a pointer to that transforamtion, You can change the transforamation in the transformation developer,its instances automatically reflect these changes.This feature can save you great deal of work.

A reusable Transformation is a reusable metadata object , defined with business logic using single Transformation.

Aggregator transformation allows you to perform aggregate calculations, such as averages and sums.

As explained above informatcia server has 3 methods to recovering the sessions.Use performing recovery to load the records from where the session fails.

power center powermart

no.of repository n No. n No.

applicability high end WH low&mid range WH

global repository supported not supported

local repository supported supported

ERP support available not available

As per my knowledge there is no such restriction to use this number of sources or targets inside a mapping.

Question is " if you make N number of tables to participate at a time in processing what is the position of your database. I organization point of view it is never encouraged to use N number of tables at a time, It reduces database and informatica server performance

The reject rows say for example due to unique key constrain is all pushed by session into the $PMBadFileDir (default relative path is <INFA_HOME/PowerCenter/server/infa_shared/BadFiles) which is configured with path at Integration Service level. Every Target will have property saying Reject filename which gives the file in which rejects rows are stored.

There r 3 types of dimensions

1.star schema

2.snowflake schema

3.glaxy schema

3 types.That are

1. SCD(slowly changing dimension) type1

2. SCD type2

3. SCD type3

Session - A Session Is A set of instructions that tells the Informatica Server How And When To Move Data From Sources To Targets. After creating the session, we can use

either the server manager or the command line program pmcmd to start or stop the session.

Batches - It Provides A Way to Group Sessions For Either Serial Or Parallel

Execution By The Informatica Server.

There Are Two Types Of Batches :

Sequential - Run Session One after the Other.

Concurrent - Run Session At The Same Time.

Batch--- is a group of any thing

Different batches ----Different groups of different things.

There are two types of batches

1. Concurrent

2. Sequential

Static cache:

We can not insert or update the cache.

Dynamic cache:

We can insert rows into the cache as we pass to the target.

1) Filter transformation is an Active transformation and Lookup is a Passive transformation

2) Filter transformation is used to Filter rows based on condition and Lookup is used to to look up data in a flat file or a relational table, view, or synonym

EDW is Enterprise Datawarehouse which means that its a centralised DW for the whole organization.

this apporach is the apporach on Imon which relies on the point of having a single warehouse/centralised where the kimball apporach says to have seperate data marts for each vertical/department.

Advantages of having a EDW:

1. Golbal view of the Data

2. Same point of source of data for all the users acroos the organization.

3. able to perform consistent analysis on a single Data Warehouse.

to over come is the time it takes to develop and also the management that is required to build a centralised database.

Java Transformation available in the 8x version and it is not available in 7x version.