Major
In case of large SCEC MySQL databases, the expunge process ( deleting already populated data in the mysql db for a workflow ) takes a long time, resulting in a spike in the memory usage.
This is because of the way expunge has been implemented in the netlogger SQL Alchemy code.
It triggers individual select statements , the results of which are then invidually deleted.
The Expunge code already does things specific to a database backend
1) for sqlite it just overwrites
Hence, for mysql it is possible to rely on database triggers in the schema definition to do cascaded deletes
This is because of the way expunge has been implemented in the netlogger SQL Alchemy code.
It triggers individual select statements , the results of which are then invidually deleted.
The Expunge code already does things specific to a database backend
1) for sqlite it just overwrites
Hence, for mysql it is possible to rely on database triggers in the schema definition to do cascaded deletes
