Tuning Database Parameters

PostgreSQL provides a wide range of configuration options that can be adjusted to meet the specific needs of our application. However, with so many options, it can be difficult to know where to start.

Before diving into the details of tuning parameters, it’s important to understand that there are two main categories of parameters: those that affect the entire cluster and those that affect only individual sessions or transactions. The former is set in the postgresql.conf configuration file, while the latter can be set in SQL statements or as environment variables for a specific connection.

Cluster-level configuration parameters

Let‘s start with a few of the most important parameters that affect the entire cluster:

• shared_buffers: This parameter specifies the amount of memory used for shared buffer cache. Increasing the value of this parameter can result in a faster database, as more data can be cached in memory. However, it’s important to remember that setting this value too high can cause the system to swap, slowing down the database.

• effective_cache_size: This parameter specifies the amount of memory the system expects to be available for disk caching. The query planner uses it to estimate the cost of using an index. Setting this parameter too low can result in the query planner making suboptimal choices, while setting it too high can result in the system using more memory than is available.

• max_connections: This parameter specifies the maximum number of concurrent connections to the database. Setting this value too high can result in the system running out of memory or becoming unresponsive, while setting it too low can limit the number of users who can access the database simultaneously.

• work_mem: This parameter specifies the amount of memory to be used by internal sort operations and hash tables before writing to temporary disk files. Setting this value too low can result in slow query performance, while setting it too high can result in the system running out of memory.