Technology 

What do basic dimensions mean?

Joe Ford

What do basic dimensions mean?

In Geometric dimensioning and tolerancing, basic dimensions are defined as a numerical value used to describe the theoretically exact size, profile, orientation or location of a feature or datum target. Basic dimensions are currently denoted by enclosing the number of the dimension in a rectangle.

What is rapidly changing dimension?

A dimension is a fast changing or rapidly changing dimension if one or more of its attributes in the table changes very fast and in many rows. If in case there are dimensions that are changing a lot, table become larger and may cause serious performance issues.

What is Type 2 slowly changing dimension?

A Slowly Changing Dimension (SCD) is a dimension that stores and manages both current and historical data over time in a data warehouse. A Type 2 SCD retains the full history of values. When the value of a chosen attribute changes, the current record is closed.

What are junk dimensions?

A junk dimension combines several low-cardinality flags and attributes into a single dimension table rather than modeling them as separate dimensions. There are good reasons to create this combined dimension, including reducing the size of the fact table and making the dimensional model easier to work with.

What are the 3 types of SCD?

What are the types of SCD?

  • Type 0 – Fixed Dimension. No changes allowed, dimension never changes.
  • Type 1 – No History. Update record directly, there is no record of historical values, only current state.
  • Type 2 – Row Versioning.
  • Type 3 – Previous Value column.
  • Type 4 – History Table.
  • Type 6 – Hybrid SCD.

How do you implement SCD Type 1 in SQL?

Here we prepare all magic, I mean… business logic:

  1. Each MERGE must have a column key: set “Business Key” for column [Id]
  2. Set “SCD1” for columns [Name] and [Telephone] as we want to update these fields every time.
  3. Set “SCD2” for column [Address] as we want to create a new row in dimension table once the value change.

How is SCD Type 2 implemented?

The steps involved are:

  1. Create the source and dimension tables in the database.
  2. Open the mapping designer tool, source analyzer and either create or import the source definition.
  3. Go to the Warehouse designer or Target designer and import the target definition.
  4. Go to the mapping designer tab and create new mapping.

What is SCD Type 3 in Informatica?

The SCD Type 3 method is used to store partial historical data in the Dimension table. The dimension table contains the current and previous data. The process involved in the implementation of SCD Type 3 in informatica is. Identifying the new record and insert it in to the dimension table.

What is SCD Type 4?

SCD type 4 provides a solution to handle the rapid changes in the dimension tables. The concept lies in creating a junk dimension or a small dimension table with all the possible values of the rapid growing attributes of the dimension. The dimension key of the new table should be maintained in the fact table.

How do you implement SCD Type 2 without using update strategy?

Have a sequence generator in the mapping and that is the Surrogate key and then at the session level treat all rows as insert. Make sure that there is no unique index. Because if the same values for those columns processed again the ETL will fail. You can’t treat all rows as Insert and build a Type 2 SCD.

How do you implement SCD Type 2 in Informatica without lookup?

We can use SCD without using lookup.

  1. Mahendra Rajpoot. Answered On : Sep 17th, 2014.
  2. Yes it is possible. Use left outer join query between source and target table in SQ to achieve look up functionality. Send this output to EXPR and then RTR for condition check SCD 2. Then insert and update Target based on RTR conditions.

What is SCD Type 2 in Informatica in interview?

  1. Join Staging Table and Dimension Table. We are going to OUTER JOIN both the Staging (Source) Table and the Dimension (Target) Table using the SQL Override below.
  2. Data Transformation.
  3. Identify Insert/Update.
  4. Insert The new Records.
  5. Update(Expire) the Old Version.
  6. Insert the new Version of Updated Record.

How do you validate SCD Type 2 in ETL Testing?

Testing Type 2 Slowly Changing Dimensions using ETL Validator

  1. Testing SCD Type 2 Dimensions.
  2. Test 1: Verifying the Current Data.
  3. Test 2: Verifying the uniqueness of the key columns in the SCD.
  4. Test 3: Verifying that historical data is preserved and new records are getting created.

Can we update target without primary key?

Your only way to update without primary key is to write an Target override in Target.By doing this, you dont need primary key for updation.

What is domain Informatica?

Informatica Domain is the fundamental administrative unit in Informatica tool. It is a collection of nodes and services. Further, this nodes and services can be categorized into folders and sub-folders based on the administration requirement.

What database does Informatica use?

PowerCenter Repository Service

Database Information Description
PowerCenter repository database type Database type for the PowerCenter repository. The PowerCenter repository supports IBM DB2 UDB, Microsoft SQL Server, Oracle, or Sybase ASE.

What is Informatica repository?

A Repository is container of information about all the objects and activities done within the tools. Informatica Repository is physically maintained under a Database System like: Oracle, SQL Server, DB2, etc. while logical parts of the repository are for the Infomatica users and tools.

Does Informatica have a database?

Informatica powersystem is one of the best ETL(Extract,transform and load) system . It can connected with various database such as RDBMS,oracle and Mysql etc.

Does Informatica involve coding?

3 Answers. Informatica has its own transformation langugage that you can use in your expressions, filter and such. It is quite versatile and not at all difficult to learn, if you’re familiar with any of the most popular programming languages of today. SQL is probably the one it resembles the most.

What is the difference between ETL and Informatica?

For managing databases, ETL means three different functions, i.e. Extract, Transform, Load. ETL becomes a combined programming tool for obtaining temporary data subsets for reports, as well as more permanent data for other purposes. Whereas Informatica is an ETL tool, used for loading data and export functions.

Is Informatica easy to learn?

Is learning Informatica easy? Yes, learning Informatica is quite easy. This Informatica tutorial will help you understand Informatica, its logic, and implementation using a variety of available data transformations.

Is Informatica worth learning?

Informatica Training is moderate expansive tool, where else tools like ab initio is very expensive which has many added advantages in technical aspect , Same time others etl tools are having there own challenges like ease of use, re-usability , debugging, connectivity which makes informatica as an ideal etl tool.

Is Informatica a good career choice?

The future of Informatica professionals is extremely high and bright. With the experience and expertization on this tool, there is a high chance of getting promoted to the next level. Learn the most fundamental skills of Informatica from ETLHive and kick start your career as an Informatica Developer.