QlikView Scripting Interview Question and Answers

The differences between these two data access protocols are technical, but in the most general terms, OLE DB is newer, more advanced, and compatible with a wider selection of database technologies. In addition, OLE DB is more general, in that it includes the ODBC functionality.

Technically speaking, ODBC (Open Database Connectivity) is designed to provide access primarily to SQL data in a multi-platform environment. OLE DB (Object Linking and Embedding Database) is designed to provide access to all types of data in an OLE Component Object Model (COM) environment. OLE DB includes the SQL functionality defined in ODBC but also defines interfaces suitable for gaining access to data other than SQL data.

A query generated via ODBC is functionally similar to a query generated by OLE DB. However, be aware that if you generate a query (via STATISTICA Query) using an ODBC connection, STATISTICA uses OLE DB to connect to the ODBC connection. Because there is an intermediate connection, ODBC queries may be slower than OLE DB queries.

Mapping Load: The mapping prefix is used on a load or select statement to create a mapping table, these tables are different from other tables. They will be stored in separate area of memory and used as mapping tables during script execution. After execution they will automatically drop.

Ex. Mapping (Load Statement/Select Statement)

Apply Map: used for mapping data from one source to another at load time.

Ex. Apply map(Map name, expr,[default expr])

Join is used to convert the given data and whenever we are using joins for converting data it is known ad Data Merging.

It has many types:

• Left join
• Right join
• Inner join, etc

Internal match fuction is used to generate data bucket of different sizes.

Extended interval match function() is used for slowly changing the dimensions.

NoConcatenation prefix is used to force the identical tables as two separate internal tables.

Incremental load is nothing but loading new or changed records from the database. With the help of QVD files we can use incremental Load.

Qlikview Generic Load is the load which is used in Qlikview for Generic database. Generic database is used in Qlikview to define the table in the transformation step. A Generic key word is used for defining the Generic Data base in the Qlikview. For Generic table we have to need at least three fields in the table and the second last column in the arbitrary key attribute in the table and the last one is the Value for the table.