1. Difference between tAggregaterow and tAggregatesortedrow.
Answer : tAggregateRow, receives a flow and aggregates it based on one or more columns. For each output line, are provided the aggregation key and the relevant result of set operations (min, max, sum).
tAggregateSortedRow receives a sorted flow and aggregates it based on one or more columns. For each output line, are provided the aggregation key and the relevant result of set operations (min, max, sum).
tAggregateSortedRow works on Sorted rows only. But tAggregateRow performs same operation without sorting rows.
tAggregateRow does not sort the result, but tAggregateSortedRow works on sorted flow that is why it produces result in sorted order.
tAggregateRow is not dependent on input row count, means we can use tAggregateRow component without knowing input row count whereas tAggregateSortedRow requires input row count in prior.
2. What is Talend data generator routine?
Answer : Talend data generator routine is a function which allow us to create group of set data. They are based on the entry of first name, address,town, etc.
3. What are the steps to replace an element in a string?
Answer : Replace one element with another in a string by using Change routine along with tJava components.
4. In talend what is the fixed pattern of date?
Answer : Default the date pattern is dd-MM-yyyy.
5. Differentiate between ETL and ELT.
Answer : ETL stands for Extract, Transform and Load which is a process that involves gaining data from exterior source, converting it to get fit into operational requirement, then load it into the end target database.
ELT stands for Extract, Load and Transform which is the process in which data is get, then loaded into the staging table in the database and then data is converted according to the need.Read this incisive blog to clearly understand the process ofETL now.
6. Talend Characteristics
Distinguishing feature => First Data integration software as a service.
Deployment =>Business modeling, graphical development.
ETL functionality => Makes ETL mapping faster and simpler for diverse data sources.
7. What is Default join for tMap.
Answer : Joining data using tMap
tMap is more powerful in terms of FUNCTIONALITY.
1. tMap can have many outputs links.
2. With tMap we can use the expression on the columns while providing the joining condition.
3. In tMap we have option to store the intermediate data in the disc.
4. In tMap, we can enable the option to reload the look-up for every record.
5. tMap supports more types of join model, includes unique join, first join and all join.
6. tMap allows you to link multiple look-up flows into it, and supports to load multiple look-up flows parallel.
7. tMap supports ‘die on error’ option.
8. For sorting data which component we generally use?
Answer : We can use tExternalSortRow and tSortRow.
9. What is MDM in talend ?
Answer : It is a management by which an organization makes and manage a single, consistent and correct view of key enterprise data.
10. Write the advantages of talend ?