during jMeter tests with many open processes I found two indexes which will improve performance significantly if there are many rows (1m+) in table ACT_RU_VARIABLE:
CREATE INDEX ACT_RU_VARIABLE_IDX1 ON ACT_RU_VARIABLE (BYTEARRAY_ID_); CREATE INDEX ACT_RU_VARIABLE_IDX2 ON ACT_RU_VARIABLE (EXECUTION_ID_);
The first index improves performance when deleting rows from table ACT_GE_BYTEARRAY: Before a row can be deleted the database has to check the foreign key constraint on column ACT_RU_VARIABLE.BYTEARRAY_ID_. Without index this results in a time-consuming full table scan of column ACT_RU_VARIABLE.BYTEARRAY_ID_ for the ID_ of the row to be deleted.
