The regular expression function is built in several databases, but many other databases do not support it. The databases that natively support regular expressions include: MySQL, PostgreSQL, Oracle 10g, and Ingres while Microsoft SQL server and Netezza do not, for example.
A different case is when the regular expression function is built in the database but the query template of the regular expression indicator is not defined.
From Profiling perspective of Talend Studio, you can:
extend the functionality of certain database servers to support the regular expression function. For more information, see Declaring a User-Defined Function in a specific database.
define the query template for a database that supports the regular expression function. For more information, see Defining a query template for a specific database.
For information about using regular expressions with Netezza, see What you need to know about some databases.