PostgreSQL Block Usage Metrics
We've added 5 new columns to Insights for PostgreSQL databases to help you better understand the effect of the shared buffer cache on your query performance, enabling you to better tune your server configuration or database sizing for optimal performance.
These columns are represented in units of "blocks": data chunks that are stored in the PostgreSQL shared buffer cache, and are the same values that are included in the buffer usage information returned by the EXPLAIN ANALYZE statement.
These new columns are:
- Block cache hit ratio – The percentage of blocks read from the shared buffers cache for this query during its execution, avoiding more costly disk reads.
- Blocks hit – The total number of blocks read from the shared buffers cache when executing this query.
- Blocks read – The total number of blocks read from disk when executing this query.
- Blocks dirtied – The total number of blocks modified (but not necessarily flushed to disk) during query execution.
- Blocks written – The total number of blocks written to disk during query execution.
More details about these and other columns can be found in the Query Insights for PostgreSQL documentation.