By full ULC

A high value for “by Full ULC” indicates that Adaptive Server is flushing the ULCs more than once per transaction, negating some performance benefits of user log caches. If the “% of total” value for “by Full ULC” is greater than 20%, consider increasing the size of the user log cache size parameter.

Increasing the ULC size increases the amount of memory required for each user connection, so you do not want to configure the ULC size to suit a small percentage of large transactions.