What is meant by lookup caches?

The Informatica server builds a cache in memory when it processes the first row of a data in a cached look up transformation. It allocates memory for the cache based on the amount you configure in the transformation or session properties. The Informatica server stores condition values in the index cache and output values in the data cache.

The result of the Lookup query and processing is the same, whether or not you cache the lookup source. However, using a lookup cache can increase session performance. You can optimize performance by caching the lookup source when the source is large.

If the lookup does not change between sessions, you can configure the transformation to use a persistent lookup cache. When you run the session, the Integration Service rebuilds the persistent cache if any cache file is missing or invalid.

The Integration Service creates the following caches for the Lookup transformation:

Data cache. For a connected Lookup transformation, stores data for the connected output ports, not including ports used in the lookup condition. For an unconnected Lookup transformation, stores data from the return port.

Index cache. Stores data for the columns used in the lookup condition.

Types of lookup caches?

1. Static cache

2. Dynamic cache

3. Persistence cache

4. Recache

5. Shared cache

Comments

Contact Me

Do You have any queries ? If you are having any query or wishing to get any type of help related Datawarehouse, OBIEE, OBIA, OAC then please e-email on below. I will reply to your email within 24 hrs. If I didn’t reply to you within 24 Hrs., Please be patience, I must be busy in some work. kashif7222@gmail.com

Top 130 SQL Interview Questions And Answers

1. Display the dept information from department table. Select * from dept; 2. Display the details of all employees Select * from emp; 3. Display the name and job for all employees Select ename ,job from emp; 4. Display name and salary for all employees. Select ename , sal from emp; 5. Display employee number and total salary for each employee. Select empno, sal+comm from emp; 6. Display employee name and annual salary for all employees. Select empno,empname,12*sal+nvl(comm,0) annualsal from emp; 7. Display the names of all employees who are working in department number 10 Select ename from emp where deptno=10; 8. Display the names of all employees working as clerks and drawing a salary more than 3000 Select ename from emp where job=’clerk’and sal>3000; 9. Display employee number and names for employees who earn commissi...

Informatica sample project

Informatica sample project - 1 CareFirst – Blue Cross Blue Shield, Maryland (April 2009 – Current) Senior ETL Developer/Lead Model Office DWH Implementation (April 2009 – Current) CareFirst Blue Cross Blue Shield is one of the leading health care insurance provided in Atlantic region of United States covering Maryland, Delaware and Washington DC. Model Office project was built to create data warehouse for multiple subject areas including Members, Claims, and Revenue etc. The project was to provide data into EDM and to third party vendor (Verisk) to develop cubes based on data provided into EDM. I was responsible for analyzing source systems data, designing and developing ETL mappings. I was also responsible for coordinating testing with analysts and users. Responsibilities: · Interacted with Data Modelers and Business Analysts to understand the requirements and the impact of the ETL on the business. · ...

Datawarehouse Architect

Search This Blog