When using a generic ODBC connection, QlikView/ Qlik Sense takes a long time to load the list of available schema, databases and tables in data selection wizard ("Select data to load"
in Qlik Sense, "Create Select Statement"
QlikView/ Qlik Sense uses methods provided by the ODBC driver to send a query and gain information about schema and tables in the database in order to populate the drop-down lists in data selection wizard.
1. Set up ODBC trace following this article
to find out which query the driver sends out when data selection wizard is opened. For example, the following query is sent by Oracle ODBC driver:
SELECT DISTINCT '', OWNER, '', '', '' FROM ALL_OBJECTS WHERE OWNER != 'PUBLIC' AND (OBJECT_TYPE='TABLE' OR OBJECT_TYPE='VIEW') ORDER BY OWNER
2. Test the query in a SQL client (such as Oracle TOAD) from the same machine. If the query is also slow in SQL client, the issue is at your database side/ ODBC driver rather than Qlik. Contact the database administrator to understand why the query takes long time to execute.
Another possibility is to try using the same DSN in a third-party tool (such as Microsoft Excel) following this article
and see if the schema and table list is loaded faster.Environments:
- QlikView all versions
- Qlik Sense all versions