informatica interview questions dwbi

While preparing for an interview i found this amazing PDF which consist of almost all the interview questions for 0 - 6 Years of experienced candidates, you can refer as well if interested. Sorter Transformation is an Active, Connected Informatica transformation used to sort data in ascending or descending order according to specified sort keys. Cracking Informatica … This one is on Informatica performance tuning. The Integration Service creates an index cache to stores the group information and data cache for the row data. An aggregator is an Active, Connected transformation which performs aggregate calculations like AVG, COUNT, FIRST, LAST, MAX, MEDIAN, MIN, PERCENTILE, STDDEV, SUM and VARIANCE. It includes around 64 questions, which, in turn, would enable you to brush your knowledge about Informatica … What the difference is between a database, a data warehouse and a data mart? Following SQL query shows you how to do it. End Value is the maximum value the Sequence Generator will generate. Stored Procedure Transformation - as the name suggests is used to execute stored procedures through Informatica ETL. On the other hand, A dynamic cache is refreshed during the session run by inserting or updating the records in cache based on the incoming source data. Explore Dwbi Openings In Your Desired Locations Now! Like the Aggregator transformation, the Rank transformation lets us group information. A Joiner is an Active and Connected transformation used to join source data from the same source system or from two related heterogeneous sources residing in different locations or file systems. What is a staging area? Join data from different Relational Databases. Informatica Scenarios I have listed the following informatica scenarios which are frequently asked in the informatica interviews. Informatica Power Center Tutorial; Data Warehouse & Business Intelligence ... MongoDB. We can define one or more conditions based on equality between the specified master and detail sources. Informatica Interview Questions: Informatica is actually a power center. To maintain employee data, we must pass a branch of the pipeline to the Aggregator Transformation and pass a branch with the same sorted source data to the Joiner transformation to maintain the original data. The fewer unique rows in the master, the fewer iterations of the join comparison occur, which speeds the join process. Here is the list of most frequently asked Informatica Interview Questions and Answers in technical interviews. When we connect the NEXTVAL output port of the Sequence Generator directly to the surrogate key columns of the target tables, the Sequence number will not be the same. Identification and elimination of performance bottlenecks will obviously optimize session performance. Next we place a Sorted Aggregator Transformation. After the Source Qualifier place a Router Transformation. We can use the Informatica Mapping Variable to extract the CDC data without using any other custom table. Do we need it? Now suppose the requirement is like that we need to have the same surrogate keys in both the targets. After it reaches the End value the session fails with the following error message: TT_11009 Sequence Generator Transformation: Overflow error. A data warehouse blog contains examples,interview questions and tutorials on Sql,Oracle Plsql,Unix Commands,Linux Commands,Informatica and Netezza. Informatica is successful ETL and EAI tool with significant industry coverage and larger success rate. Discuss each question in detail for better understanding and in-depth knowledge of Informatica By default, the aggregator transformation treats null values as NULL in aggregate functions. Privacy Policy | You can configure number of retry attempts. Do we need it? These Informatica questions and answers are suitable for both freshers and experienced professionals at any level. If we have sorted both the master and detail pipelines in order of the ports say ITEM_NO, ITEM_NAME and PRICE we must ensure that: The best option is to place the Joiner transformation directly after the sort origin to maintain sorted data. Normal,Master Outer,Detail Outer and Full Outer. Hence the next approach may be we use a Sorter Transformation and check the Distinct option. Suppose we have 5 rows coming from the source, so the targets will have the sequence values as TGT1 (1,2,3,4,5) and TGT2 (6,7,8,9,10). Answer : … Filter transformation limits the row set sent to a target. A block of sequence numbers is sent to one target tables surrogate key column. Informatica 9x allows us to configure Lookup transformation to return multiple rows. Explain the what are all process will be started when we execute a workflow? Popular Posts. If the amount of incoming data is greater than the amount of Sorter cache size, the Integration Service temporarily stores data in the Sorter transformation work directory. The Joiner transformation accepts input from most transformations. During a session, the Integration Service compares an input row with rows in the data cache. The Case Sensitive property determines whether the Integration Service considers case when sorting data. It stores the ranking position for each row in a group. Joiner transformation cannot be used when either of the input pipeline contains an, Joiner transformation cannot be used if we connect a. Otherwise, it does not use blocking logic. Filter transformation restricts or blocks the incoming record set based on one given condition. What is a staging area? What are the differences between Source Qualifier and Joiner Transformation? What is the purpose of a staging area? The Integration Service orders the target load on a row-by-row basis. Informatica metadata repository stores and maintains information about all the objects in Informatica. But we can specify to treat null values in aggregate functions as NULL or zero. EDB develops and integrates performance, security, and manageability enhancements into PostgreSQL to support enterprise-class workloads for its database, EDB Postgres Advanced Server. If we select Cycle, the Integration Service cycles back to this value when it reaches the end value. For more details on how the mapping is performed please visit Working with Normalizer. New Features of Informatica … Welcome to the finest collection of Informatica Interview Questions with standard answers that you can count on. If the Integration Service requires more space as allocated for the index and data cache sizes in the transformation properties, it stores overflow values in cache files i.e. In this article let us take up a very trivial but an important aspect that we as DW developers usual face. Using Persistent Cache, you may save lot of your time. Informatica PowerCentre stores all the information about mapping, session, transformation, workflow etc. WHEN statement in SQL (Or Switch().. Case statement in C). If the Integration Service cannot finish processing and committing data, we can issue the abort command. And Cached lookup can be either static or dynamic. DWBI Guru Is DWBI changing from traditional ETL & Reporting framework? A Sequence Generator transformation is a Passive and Connected transformation that generates numeric values. If we have multiple Source Qualifier transformations connected to multiple targets, we can designate the order in which the Integration Service loads data into the targets. Example: Expression transformation. This section will list out all the DB questions that might hit you while facing an Informatica Interview. First steps in solving a data quality problem is to perform data profiling, that is to verify the level of accuracy of the source data. Interview. Blocking logic is possible if master and detail input to the Joiner transformation originate from different sources. We will use the very basic concept of the Expression Transformation that at a time we can access the previous row data as well as the currently processed data in an expression transformation. The differences are illustrated in the below table: An active transformation is the one that performs any of the following actions: On the other hand a passive transformation is the one which does not change the number of rows that pass through it. The record set should be sorted on those columns that are used in Group By operation. What are the differences between Source Qualifier and Joiner Transformation? On certain cases, you may get huge performance gain using this technique! These information can serve many purposes while accessed through external SQL query. Read and understand all the questions and their answers below and in the following pages to get a good grasp in Informatica. We will sort the source data based on STUDENT_NAME ascending followed by SUBJECT ascending. Here since the source system is a Flat File you will not be able to select the distinct option in the source qualifier as it will be disabled due to flat file source table. Cassandra. Informatica - 1168 Informatica interview questions and 3208 answers by expert members with experience in Informatica subject. Here we will be taking the aggregated pipeline as the Master and original dataflow as Detail Pipeline. In contrast ABORT command has a timeout period of 60 seconds. The Sorter transformation contains only input/output ports. How to generate sequence numbers using expression transformation? Menu Skip to content. Do we need it? These informatica scenario interview questions helps … Informatica Power Center Tutorial; ... Once we configure the Informatica Repository in DVO, we can refresh objects by refreshing the Repository or we can refresh by Individual folders. Use the Joiner transformation when we need to join the following types of sources: Sybase supports a maximum of 16 columns in an ORDER BY clause. But what if the source is a flat file? Home; About us; Informatica Data Quality. In case of static or read-only lookup cache the Integration Service caches the lookup table at the beginning of the session and does not update the lookup cache while it processes the Lookup transformation. First of all we need an Expression Transformation where we have all the source table columns and along with that we have another i/o port say seq_num, which is gets sequence numbers for each source row from the port NextVal of a Sequence Generator start value 0 and increment by 1. Database deadlock resilience feature - this will ensure that your session does not immediately fail if it encounters any database deadlock, it will now retry the operation again. Download Free Best Informatica Interview Questions Answers Dwbi to the finest collection of Informatica Interview Questions with standard answers that you can count on. When we select the distinct option all the columns will the selected as keys, in ascending order by default. The Source Qualifier … Filter transformation filters rows from within a mapping. Informatica Power Center Tutorial; ... Once we configure the Informatica Repository in DVO, we can refresh objects by refreshing the Repository or we can refresh by Individual folders. Other ways to handle duplicate records in source batch run is to use an Aggregator Transformation and using the Group By checkbox on the ports having duplicate occurring data. 2. Select Distinct option is used when we want the Integration Service to select unique values from a source, filtering out unnecessary data earlier in the data flow, which might improve performance. Now based on STUDENT_NAME in GROUP BY clause the following output subject columns are populated as. For more details check, Dynamic Lookup Cache. We can use OPB_MAPPING and OPB_SUBJECT tables residing under informatica Repository to obtain information about all the mappings under each Informatica Folder. Interview Questions; Tutorials. paging to disk. Solution: In the expression transformation, create a variable port and increment it by 1. This article finds out. Subscribe for free e-Book. Interview Loc - Bangalore. What Can We Do To Improve The Performance Of Informatica Aggregator Transformation? Database includes a … New Features of Informatica … Informatica DVO. These informatica scenario interview questions helps you a lot in gaining confidence in interviews. In the session level, we should set the target property as "Update as Update" and check the "Update" check-box. Exactly where do you use this transformation? Normal,Master Outer,Detail Outer and Full Outer. This allows the Integration Service to update the target incrementally, rather than forcing it to delete previous loads data, process the entire source data and recalculate the same data each time you run the session. The Integration Service passes all incoming data into the Sorter Cache before Sorter transformation performs the sort operation. [Taken into consideration Start Value 0, Current value 1 and Increment by 1. What we need is simple Sorter, Expression and Filter transformation to achieve aggregation at Informatica level. There are loads of mis-information spreaded across Internet on good use-cases of Informatica Stored Procedure transformation. Also if the input data is properly sorted, the session may fail if the sort order by ports and the group by ports of the aggregator are not in the same order. Lookup transformation is used to look up a source, source qualifier, … I applied online. For detailed understanding visit Aggregation without Aggregator. Read and understand all the questions and their answers below and in the following pages to get a good grasp in Informatica. According to research Informatica … When the Sorter transformation is configured to treat output rows as distinct, it assigns all ports as part of the sort key. The numeric equivalent of FALSE is zero (0) and any non-zero value is the equivalent of TRUE. Menu. Now the filter condition for the three router groups will be: After we create a mapping to load data in target database from flat files, next we move on to the session property of the Source Qualifier. Interview Questions; Tutorials. After reaching this value the session will fail if the sequence generator is not configured to cycle.Default is 2147483647. It is widely used as an information, extraction, transformation and loading tool. Top 50 DWBI Interview Questions with Answers - Part 2 ... Best Informatica Interview Questions & Answers Welcome to the finest collection of Informatica Interview Questions with standard answers that you can count on. In this article we shall see how we can implement SCD type2 in Informatica using ORA_HASH, which is an ORACLE function that computes hash value for a given expression. But when we check Sorted Input the Integration Service uses memory to process an Aggregator transformation it does not use cache files. So now we can retrieve multiple rows from a lookup table thus making Lookup transformation an Active transformation type. The join condition contains ports from both input sources that must match for the Integration Service to join two rows. For this, we need to define the key in the target table in Informatica level and then we need to connect the key and the field we want to update in the mapping Target. Suppose we want to maintain the last extraction date in a flatfile, based on that value we want to capture the changed data of our business table. These Informatica questions and answers are suitable for both freshers and experienced professionals at any level. But you should be aware of the hazards of persistent cache as well. In case of dynamic lookup cache the Integration Service dynamically inserts or updates data in the lookup cache and passes the data to the target. Terms of Use | Incremental Aggregation, session option is enabled. Informatica Interview Questions. What is the purpose of a staging area? If a result set includes fields that do not contain data in either of the sources, the Joiner transformation populates the empty fields with null values. We can configure a Lookup transformation to cache the underlying lookup table. Data analytics is the science of examining … 3. Number of sequential values the Integration Service caches at a time. Like a reusable transformation when we use a mapplet in a mapping, we use an instance of the mapplet and any change made to the mapplet is inherited by all instances of the mapplet. Informatica Interview Questions (lead level) Informatica Data Quality. A Lookup is a Passive, Connected or Unconnected Transformation used to look up data in a relational table, view, synonym or flat file. The choice and use of correct type of Look-Up can dramatically vary the session performance in Informatica. If we skip ITEM_NAME and join on ITEM_NO and PRICE, we will, Mapplet [if it contains any one of the above mentioned transformations]. Popular Posts. So next we need Sorted Joiner Transformation to join the sorted aggregated data with the original data, based on DEPTNO. In this "DWBI Concepts' Original article", we put Oracle database and Informatica PowerCentre to lock horns to prove which one of them handles data SORTing operation faster. When we join both branches of the pipeline, we join the aggregated data with the original data. Disable this option if we want the Integration Service to treat null values as higher than any other value. Best Informatica Interview Questions & Answers Given below is a list of the most commonly asked interview questions and answers. Learn DWBI Technologies. Know How. Mismatch or Changing the order of the list of selected columns to that of the connected transformation output ports may result is session failure. CouchDB. Hence only the user defined SQL Query will be fired in the database and all the other options will be ignored. In the Mapping Designer, We need to configure the Target Load Plan based on the Source Qualifier transformations in a mapping to specify the required loading order. whenever the Integration Service reaches the configured end value for the sequence, it wraps around and starts the cycle again, beginning with the configured Start Value. You may also read this article to know how to tune the performance of aggregator transformation. Informatica Power Center Tutorial; ... 300+ real time interview questions with scenarios Informatica Data Quality . Informatica Interview Questions (lead level) Informatica Product Suite. The Transformation which Converts the source (relational or flat) data type to Informatica datatype.So it works as an intemediator between and source and informatica server. The Integration Service blocks the detail source while it caches rows from the master source. Discarded rows do not appear in the session log or reject files. Failing of session can be handled if the Sequence Generator is configured to Cycle through the sequence, i.e. Tasks performed by qualifier transformation: - 1. As the name suggests, this tool will help you tune the performance of Informatica sessions fully automatically. Subscribe for free e-Book. Join data originating from the same source database. A Mapplet is a reusable object created in the Mapplet Designer which contains a set of transformations and lets us reuse the transformation logic in multiple mappings. We can use this feature to find the existence of any change in any of the SCD column. Explain Informatica Architecture ? The aggregate expression contains nested aggregate functions. This article gives a crucial insight to application developer in order to take informed decision regarding performance tuning. A static cache is one which does not modify the cache once it is built and it remains same during the session run. For every row generated by an active source, the Integration Service loads the corresponding transformed row first to the primary key table, then to the foreign key table. For performance reasons, I recommend you ONLY use JOINER transformation if any of the following condition is true –. Sort based on DEPTNO port. To load a set of source files we need to create a file say final.txt containing the source flat file names, ten files in our case and set the Source filetype option as Indirect. Reply Delete Share. In a real-time environment you can control the session log file size or time. If we need to use two ports in the join condition with non-matching datatypes we must convert the datatypes so that they match. Explain Informatica Architecture ? Default value for a standard Sequence Generator is 0. We are going to do is, to call C++ Executable from Informatica, using Passive Java Transform and capture the output of the C++ using Java and write the result to corresponding target column. Popular Posts. However, if we specify particularly the FIRST function, the Integration Service then returns the value of the specified first row of the group.