Interview › Databases & Caching
What is an RDS parameter group, and give an example of a parameter you would tune?
Databases & Caching · Basic level
Answer
An RDS parameter group is a managed set of database engine configuration parameters. It controls behavior such as logging, memory-related settings, connection limits, TLS enforcement flags, query planner settings, and extension preload settings.
Technical explanation
Some parameters are dynamic; others require reboot, so the apply type must be checked before production change.
Parameter groups should be managed through IaC and promoted through environments.
Changing max_connections, logging, or planner parameters can have broad performance impact and should be measured.
Hands-on example
PostgreSQL slow query visibility example:
Set log_min_duration_statement = 500
Set shared_preload_libraries = pg_stat_statements
Then run:
CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
SELECT query, calls, total_exec_time, mean_exec_time FROM pg_stat_statements ORDER BY total_exec_time DESC LIMIT 10;
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