Query Performance
Typical business intelligence and data warehouse issues:
- Queries take too long to finish or don't finish at all
- Performance degrades as data increases and queries increase
Causes:
- Concurrency
- Too many users hitting the system at once
- Queries being run are too complex
- Data volume chokes system
- Rich queries require computations that a single node vertically-scaled database cannot handle
- Overloaded system causes errors to return an error to the user, or hours/days of waiting
- Can store the data but can't analyze – data is outpacing the fixed amount of CPU, memory, and network resources
- Network becomes bottleneck
- Network interconnect choked due to the sheer amount of data
- Queries run inefficiently, requiring multiple passes over data or materialized views
Remedies: