Symptoms
In a Microsoft Skype for Business Server 2015 environment, if a user creates many ephemeral conferences, the excessive number of delete log entries could slow down the system.
After you apply this update, the Skype for Business Server allows merging the transaction log in cases in which the logical operations cancel one another out. Therefore, these log entries will be deleted more effectively from the Persisted Service Data (PSD) table.
Resolution
To fix this issue, install the July 2018 cumulative update 6.0.9319.534 for Skype for Business Server 2015, Core Components.