# Managing User-Defined Functions in databases

Available in...

* Big Data Platform
* Cloud API Services Platform
* Cloud Big Data Platform
* Cloud Data Fabric
* Cloud Data Management Platform
* Data Fabric
* Data Management Platform
* Data Services Platform
* Qlik Talend Cloud Enterprise Edition
* Qlik Talend Cloud Premium Edition
* Real-Time Big Data Platform

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 the Profiling perspective, you can:

* Extend the functionality of certain database servers to support the regular expression function; and
* Define the query template for a database that supports the regular expression function.

### In this section

* [Declaring a User-Defined Function in a specific database](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2026-09/declaring-user-defined-function-in-specific-database)
* [Defining a query template for a specific database](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2026-09/defining-query-template-for-specific-database)
* [Editing a query template](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2026-09/editing-query-template)
* [Deleting a query template](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2026-09/deleting-query-template)