Transformations In Informatica Presented By QuontraSolutions

Information about Transformations In Informatica Presented By QuontraSolutions

Published on September 8, 2014

Author: quontra123



Informatica Transformations : Informatica Transformations IT Courses Online Training and Placements: IT Courses Online Training and Placements Quontra Solutions For Free Demo Contact US: 3427 Vintage cir , SE Smyrna, GA-30080 Phone :  (404)-900-9988                (404)-990-3007 Email: [email protected] Visit Us : Transformations: Transformations A transformation is a repository object that generates, modifies, or passes data The Designer provides a set of transformations that perform specific functions Data passes into and out of transformations through ports that you connect in a mapping or mapplet Transformations can be active or passive Transformations: Transformations Active transformations Aggregator performs aggregate calculations Filter serves as a conditional filter Router serves as a conditional filter (more than one filters) Joiner allows for heterogeneous joins Source qualifier represents all data queried from the source Passive transformations Expression performs simple calculations Lookup looks up values and passes to other objects Sequence generator generates unique ID values Stored procedure calls a stored procedure and captures return values Update strategy allows for logic to insert, update, delete, or reject data Transformations Contd..: Transformations Contd.. Create the transformation . Create it in the Mapping Designer as part of a mapping, in the Mapplet Designer as part of a Mapplet, or in the Transformation Developer as a reusable transformation. Configure the transformation . Each type of transformation has a unique set of options that you can configure. Connect the transformation to other transformations and target definitions . Drag one port to another to connect them in the mapping or Mapplet . Expression Transformation: Expression Transformation You can use the Expression transformations to calculate values in a single row before you write to the target. For example, you might need to adjust employee salaries, concatenate first and last names, or convert strings to numbers. You can use the Expression transformation to perform any non-aggregate calculations. You can also use the Expression transformation to test conditional statements before you output the results to target tables or other transformations. Expression Transformation: Expression Transformation Calculating Values To use the Expression transformation to calculate values for a single row, you must include the following ports: Input or input/output ports for each value used in the calculation . For example, when calculating the total price for an order, determined by multiplying the unit price by the quantity ordered, the input or input/output ports. One port provides the unit price and the other provides the quantity ordered. Output port for the expression . You enter the expression as a configuration option for the output port. The return value for the output port needs to match the return value of the expression. Variable Port : Variable Port is used like local variable inside Expression Transformation , which can be used in other calculations Source Qualifier Transformation: Source Qualifier Transformation Every mapping includes a Source Qualifier transformation, representing all the columns of information read from a source and temporarily stored by the Informatica Server. In addition, you can add transformations such as a calculating sum, looking up a value, or generating a unique ID that modify information before it reaches the target. Source Qualifier Transformation: Source Qualifier Transformation When you add a relational or a flat file source definition to a mapping, you need to connect it to a Source Qualifier transformation. The Source Qualifier represents the records that the Informatica Server reads when it runs a session. You can use the Source Qualifier to perform the following tasks: Join data originating from the same source database. You can join two or more tables with primary-foreign key relationships by linking the sources to one Source Qualifier. Filter records when the Informatica Server reads source data. If you include a filter condition, the Informatica Server adds a WHERE clause to the default query. Specify an outer join rather than the default inner join . If you include a user-defined join, the Informatica Server replaces the join information specified by the metadata in the SQL query. Specify sorted ports . If you specify a number for sorted ports, the Informatica Server adds an ORDER BY clause to the default SQL query. Select only distinct values from the source . If you choose Select Distinct, the Informatica Server adds a SELECT DISTINCT statement to the default SQL query. Create a custom query to issue a special SELECT statement for the Informatica Server to read source data. For example, you might use a custom query to perform aggregate calculations or execute a stored procedure Configuring Source Qualifier Transformation: Configuring Source Qualifier Transformation To configure a Source Qualifier: In the Designer, open a mapping. Double-click the title bar of the Source Qualifier. In the Edit Transformations dialog box, click Rename, enter a descriptive name for the transformation, and click OK. The naming convention for Source Qualifier transformations is SQ_ TransformationName ,. Click the Properties tab. Configuring Source Qualifier: Configuring Source Qualifier Option Description SQL Query Defines a custom query that replaces the default query the Informatica Server uses to read data from sources represented in this Source Qualifier User-Defined Join Specifies the condition used to join data from multiple sources represented in the same Source Qualifier transformation Source Filter Specifies the filter condition the Informatica Server applies when querying records. Number of Sorted Ports Indicates the number of columns used when sorting records queried from relational sources. If you select this option, the Informatica Server adds an ORDER BY to the default query when it reads source records. The ORDER BY includes the number of ports specified, starting from the top of the Source Qualifier. When selected, the database sort order must match the session sort order. Tracing Level Sets the amount of detail included in the session log when you run a session containing this transformation. Select Distinct Specifies if you want to select only unique records. The Informatica Server includes a SELECT DISTINCT statement if you choose this option. Joiner Transformation: Joiner Transformation While a Source Qualifier transformation can join data originating from a common source database, the Joiner transformation joins two related heterogeneous sources residing in different locations or file systems. The combination of sources can be varied. You can use the following sources: Two relational tables existing in separate databases Two flat files in potentially different file systems Two different ODBC sources Two instances of the same XML source A relational table and a flat file source A relational table and an XML source If two relational sources contain keys, then a Source Qualifier transformation can easily join the sources on those keys. Joiner transformations typically combine information from two different sources that do not have matching keys, such as flat file sources. The Joiner transformation allows you to join sources that contain binary data. Creating a Joiner Transformation: Creating a Joiner Transformation To create a Joiner Transformation: In the Mapping Designer, choose Transformation-Create. Select the Joiner transformation. Enter a name for the Joiner. Click OK. The naming convention for Joiner transformations is JNR_ TransformationName . Enter a description for the transformation. This description appears in the Repository Manager, making it easier for you or others to understand or remember what the transformation does. The Designer creates the Joiner transformation. Keep in mind that you cannot use a Sequence Generator or Update Strategy transformation as a source to a Joiner transformation. Drag all the desired input/output ports from the first source into the Joiner transformation. The Designer creates input/output ports for the source fields in the Joiner as detail fields by default. You can edit this property later. Select and drag all the desired input/output ports from the second source into the Joiner transformation. The Designer configures the second set of source fields and master fields by default. Double-click the title bar of the Joiner transformation to open the Edit Transformations dialog box. Select the Ports tab. Click any box in the M column to switch the master/detail relationship for the sources. Change the master/detail relationship if necessary by selecting the master source in the M column. Creating a Joiner Transformation: Creating a Joiner Transformation Select the Condition tab and set the condition. Configuring Joiner transformation: Configuring Joiner transformation Joiner Setting Description Case-Sensitive String Comparison If selected, the Informatica Server uses case-sensitive string comparisons when performing joins on string columns. Cache Directory Specifies the directory used to cache master records and the index to these records. By default, the caches are created in a directory specified by the server variable $PMCacheDir. If you override the directory, be sure there is enough disk space on the file system. The directory can be a mapped or mounted drive. Join Type Specifies the type of join: Normal, Master Outer, Detail Outer, or Full Outer. PowerPoint Presentation: Used to look up data in a relational table, view, synonym or Flat File. It compares Lookup transformation port values to lookup table column values based on the lookup condition. Connected Lookups Receives input values directly from another transformation in the pipeline For each input row, the Informatica Server queries the lookup table or cache based on the lookup ports and the condition in the transformation Passes return values from the query to the next transformation Un Connected Lookups Receives input values from an expression using the :LKP (:LKP.lookup_transformation_name (argument, argument, ...)) reference qualifier to call the lookup and returns one value. With unconnected Lookups, you can pass multiple input values into the transformation, but only one column of data out of the transformation Lookup Transformation Lookup Transformation: Lookup Transformation You can configure the Lookup transformation to perform different types of lookups. You can configure the transformation to be connected or unconnected, cached or uncached: Connected or unconnected . Connected and unconnected transformations receive input and send output in different ways. Cached or uncached. Sometimes you can improve session performance by caching the lookup table. If you cache the lookup table, you can choose to use a dynamic or static cache. By default, the lookup cache remains static and does not change during the session. With a dynamic cache, the Informatica Server inserts rows into the cache during the session. Informatica recommends that you cache the target table as the lookup. This enables you to look up values in the target and insert them if they do not exist. Diff bet Connected & Unconnected Lookup: Diff bet Connected & Unconnected Lookup Connected lookup Unconnected lookup 1) Receives input values directly from  of a the pipe line transformation . Receives input values from the result of LKP expression within other transformation. 2) U can use a dynamic or static cache   U can use a static cache. 3) Cache includes all lookup columns used in the mapping. Cache includes all lookup out put ports. 4) Support user defined default values Does not support user defined default values Diff between Static & Dynamic Cache: Diff between Static & Dynamic Cache Static Cache Dynamic Cache 1)  U can not insert or update the cache U can insert rows into the cache as u pass to the target 2) The Informatica Server does not update the cache while it processes the Lookup transformation The Informatica Server dynamically inserts data into the lookup cache and passes data to the target table. Update Strategy Transformation: Update Strategy Transformation When you design your data warehouse, you need to decide what type of information to store in targets. As part of your target table design, you need to determine whether to maintain all the historic data or just the most recent changes. For example, you might have a target table, T_CUSTOMERS, that contains customer data. When a customer address changes, you may want to save the original address in the table, instead of updating that portion of the customer record. In this case, you would create a new record containing the updated address, and preserve the original record with the old customer address. This illustrates how you might store historical information in a target table. However, if you want the T_CUSTOMERS table to be a snapshot of current customer data, you would update the existing customer record and lose the original address. The model you choose constitutes your update strategy , how to handle changes to existing records. In Power Mart and Power Center, you set your update strategy at two different levels: Within a session . When you configure a session, you can instruct the Informatica Server to either treat all records in the same way (for example, treat all records as inserts), or use instructions coded into the session mapping to flag records for different database operations. Within a mapping. Within a mapping, you use the Update Strategy transformation to flag records for insert, delete, update, or reject . Setting up Update Strategy at Session Level: Setting up Update Strategy at Session Level During session configuration, you can select a single database operation for all records. For the Treat Rows As setting, you have the following options: Setting Description Insert Treat all records as inserts. If inserting the record violates a primary or foreign key constraint in the database, the Informatica Server rejects the record. Delete Treat all records as deletes. For each record, if the Informatica Server finds a corresponding record in the target table (based on the primary key value), the Informatica Server deletes it. Note that the primary key constraint must exist in the target definition in the repository. Update Treat all records as updates. For each record, the Informatica Server looks for a matching primary key value in the target table. If it exists, the Informatica Server updates the record. Again, the primary key constraint must exist in the target definition. Data Driven The Informatica Server follows instructions coded into Update Strategy transformations within the session mapping to determine how to flag records for insert, delete, update, or reject. If the mapping for the session contains an Update Strategy transformation, this field is marked Data Driven by default. If you do not choose Data Driven setting, the Informatica Server ignores all Update Strategy transformations in the mapping. Update Strategy Settings setting you choose depends on your update strategy and the status of data in target tables: : Update Strategy Settings setting you choose depends on your update strategy and the status of data in target tables: Setting Use To Insert Populate the target tables for the first time, or maintaining a historical data warehouse. In the latter case, you must set this strategy for the entire data warehouse, not just a select group of target tables. Delete Clear target tables. Update Update target tables. You might choose this setting whether your data warehouse contains historical data or a snapshot. Later, when you configure how to update individual target tables, you can determine whether to insert updated records as new records or use the updated information to modify existing records in the target. Data Driven Exert finer control over how you flag records for insert, delete, update, or reject. Choose this setting if records destined for the same table need to be flagged on occasion for one operation (for example, update), or for a different operation (for example, reject). In addition, this setting provides the only way you can flag records for reject. Thank you Expecting a Response from you for free Demo : Thank you Expecting a Response from you for free Demo

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