What is the difference between lookup and joiner transformation?
Joiner is used for joining two homogeneous or heterogeneous sources residing at different locations. Lookup is used to look-up the data. Joiner is an Active Transformation. Lookup transformation is a Passive transformation.
How does Joiner improve session performance?
Use the following tips to improve session performance with the Joiner transformation:
- Designate the master source as the source with fewer duplicate key values.
- Designate the master source as the source with fewer rows.
- Perform joins in a database when possible.
- Join sorted data when possible.
How can we improve the performance of lookup transformation in Informatica?
Optimizing Lookup Transformations
- Use the optimal database driver.
- Cache lookup tables.
- Optimize the lookup condition.
- Filter lookup rows.
- Index the lookup table.
- Optimize multiple lookups.
- Create a pipeline Lookup transformation and configure partitions in the pipeline that builds the lookup source.
How do you use lookup to tune performance of Informatica?
You can improve performance for the following types of lookups:
- Cached lookups. To improve performance, index the columns in the lookup ORDER BY statement. The mapping log file contains the ORDER BY statement.
- Uncached lookups. To improve performance, index the columns in the lookup condition.
Which is faster joiner or lookup?
Sometimes joiner gives more performance and sometimes lookups. In case of Flat file, generally, sorted joiner is more effective than lookup, because sorted joiner uses join conditions and caches less rows. Lookup caches always whole file.
What kind of join is lookup?
Lookup works as left outer join (LOJ). You can do an inner join with the help of DROP condition.
What is lookup transformation in Informatica?
The Lookup transformation returns the result of the lookup to the target or another transformation. You can configure the Lookup transformation to return a single row or multiple rows. When you configure the Lookup transformation to return a single row, the Lookup transformation is a passive transformation.
How can mapping performance be improved?
To maximize session performance, keep the Filter transformation as close as possible to the sources in the mapping. Rather than passing rows that you plan to discard through the mapping, you can filter out unwanted data early in the flow of data from sources to targets.
What is the difference between connected and UnConnected lookup in Informatica?
Differences between Connected and UnConnected Lookup Transformation: Connected lookup receives input values directly from mapping pipeline, whereas UnConnected lookup receives values from the lookup expression from another transformation.
What is pre build lookup cache in Informatica?
The ‘Pre-build lookup cache’ property works in conjunction with ‘Configure the Additional Concurrent Pipelines for Lookup Cache Creation’ session property. The Integration Service can pre-build lookup cache if the ‘Configure the Aditional ..’ property is greater than zero.
What is Joiner transformation?
Joiner transformation is an active and connected transformation. It provides the option of creating joins in the Informatica. By using the joiner transformation, the created joins are similar to the joins in databases. The joiner transformation is used to join two heterogeneous sources.
What is the difference between a lookup and a joiner?
Whereas Joiner, can join variou types of sources supported by informatica. We’ve found that we can increase performance of some of our mappings by using the Joiner in place of the Lookup. Has anyone else experienced this?
Can We do a RIGHT OUTER JOIN using lookup?
FULL OUTER JOINS and RIGHT OUTER JOINS cannot be done using a lookup. Joiners help pull together heterogenous sources. If you have push down, use of joiners is encouraged to use DB Resources. can we perform a left outer join using lookup?
What is the difference between lookup transformation and joiner transformation?
Lookup Transformation and Joiner transformation are two different things although the functionality of these two have some similarity but Joiner has more capability rather than Lookup transformation and in Joiner we can perform various types of joins which is not possible in Lookup Transformation.
What is the difference between lookup and inner join in SQL?
Lookup does Left outer join by default (Considering your source as Left table). Only diff in SQL left outer join and Lookup join is if we have mutiple matches for a record in LKp, we get only one record as output. But, even this is taken care in 9x Version. Lookup will not do Inner Join.