Huge size of table ARCH_DATA_INSTANCE on an oracle Database

Q&A
1

Hi,

We noticed that ARCH_DATA_INSTANCE table takes 60 GB on Oracle database.

SELECT SUM( dbms_lob.getLength( clobvalue ) ) FROM ARCH_DATA_INSTANCE;

Column CLOBVALUE seems to contains values of variables, result of workflows.

Could we clean this table without impacting running workflows or historical of workflows?

Regards

2

Hello,

The Engine is stateless which means that everything that is necessary for execution is persisted by default. This includes historical data (archive) because of audit and provided APIs. Some tables get bigger depending on the Engine activity and the amount of data you store as part of process variables. The second reason should not occur if you follow the best practices: use process variables only when necessary and with a light type.

In the Enterprise Edition it is possible to configure archiving, you can check this documentation page here .

Most of the time, the solution used is to regularly purge the data that is not useful anymore using APIs (remove unused process definitions, archived cases, data, others).

3

Hi Pierrick,

Thank you for your answer.
We will delete from table old records.
We noticed, it is the MDM context record which consuming space.

Regards

4

Pierrick,
Thank you for your follow up.