In any databases, a user query can lock another user session. One of the main reasons would be the SQL syntaxes used which would lock rows of data while the query is executing. Lock is a normal mecanism which keeps in place data integrity. However when too much data is accessed and modified at the same time from different and independant transactions, waiting situations happened.
How to investigate futher a sap hana user session locking another user transaction?
When sessions start blocking other sessions, don't wait, look at the problem immediately. It could eventually bring your database to a standstill.
Using hana studio console administration, select the performance tab, than the session tab.
1/ Investigation on sessions and transactions. Is there any locked sessions?
2/ For futher analyses, trace session SQL and Execution plan.
3/ Check whether there is a transaction waiting.
4/ If necessary cancel the blocking session.