Metadata call to query tables may block new logins

Detail name	Value
Changelog Number	7245
Type	Bug
Status	Resolved
Affected Versions	EXASOL 6.0.0, Exasol 6.1.0
Fix Versions	Exasol 7.0.0, Exasol 6.1.9, Exasol 6.2.5, Exasol 7.0.0-alpha1
Resolution Date	2020-03-24

General information

ODBC, JDBC and ADO.NET driver can query information about the tables in the database by calling metadata functions:
ODBC: SQLTables()
JDBC: getTables()
ADO.NET: getSchema(Tables)

In some scenarios this may take a long time which can cause problems for new login requests. New logins will be delayed until the metadata function has finished.

Workaround

Use an active session slot during execution of this metadata call (see SOL-296 for details on session management).

Alternatively you can force the driver to send metadata requests as SQL statement. For this add the following parameter to the connection string:

 JDBC: metadataSQL=1
 ODBC: LEGACYCATALOG=Y