The PEGA0060 alert is triggered when the number of Interaction History records retrieved for a customer or any other entity that is associated with a decision is above the threshold.
There is a table named PR_DATA_IH_FACT which contains transactional data that may grow fast.I believe high size of this table is generating this alert.You can check with your bussiness and keep only those data which is required.Generally we suggest to have 30 days data only.
Pega0078:The PEGA0078 alert is triggered when the number of records that are returned by a Compose shape in a particular data flow is above the threshold. The default value for the threshold is 250 records.. Too many records returned by the Compose shape can cause performance issues.
To eliminate this alert, check the join condition in the Compose shape for potential abnormalities and apply changes that are needed to reduce the number of records returned. If the condition is correct and the number of records can be accepted (they do not cause performance issues), consider increasing the threshold value for the alert. Increasing the heap size to accommodate for the increased number of records in memory is also an option to reduce performance issues