Database Memory Tuning Calculator
Most database installs run on defaults sized for a machine with a fraction of the RAM they actually have. Pick your engine and get a starting config block based on established tuning ratios.
innodb_buffer_pool_size
innodb_log_file_size
Budget per connection
my.cnf block
shared_buffers
effective_cache_size
work_mem
postgresql.conf block
If max_connections needs to be high (200+), put PgBouncer in front
instead of raising it directly — PostgreSQL's per-connection
overhead makes very high connection counts expensive on their own.