Recommend at least three specific tasks that could be performed to improve the quality of data sets using the software development life cycle $($SDLC$)$ methodology. Include a thorough description of each activity per each phase.

Recommend the actions that should be performed to optimize record selections and to improve database performance from a quantitative data quality assessment.

Suggest three maintenance plans and three activities that could be performed to improve data quality.

Suggest methods that would be efficient for planning proactive concurrency control methods and lock granularities. Assess how your selected method can be used to minimize the database security risks that may occur within a multiuser environment.

Analyze how the method can be used to plan out the system effectively and ensure that the number of transactions does not produce record$-$level locking while the database is in operation.