Database Metrics

The Databases metric group contains metrics providing information about the usage and performance of databases in your PostgreSQL cluster. The metrics available are:

• Databases – Connection count
• Databases – Row metrics
• Databases – Deadlocks
• Databases – Buffer cache hits
• Databases – Blocks read
• Databases – Transactions committed & rolled back
• Databases – Temp bytes

Connection Count

The Connection Count metric provides the number of connections against a PostgreSQL database.

Row Metrics

Rows inserted

The Rows inserted metric provides the number of rows inserted in a PostgreSQL database each second.

Rows updated

The Rows updated metric provides the number of rows updated in the PostgreSQL database each second.

Rows deleted

The Rows deleted metric provides the number of rows deleted in the PostgreSQL database each second.

Rows returned

The Rows returned metric provides the number of rows returned from a PostgreSQL database each second.

Rows fetched

The Rows fetched metric provides the number of rows fetched from a PostgreSQL database each second.

Deadlocks

The Connection Count metric provides the number of deadlocks in a database at a given point in time. A deadlock occurs when two or more transactions hold locks that the other needs to acquire. This prevents the transactions from acquiring the required locks, blocking them from proceeding. PostgreSQL automatically resolves this by aborting one of the transactions.

Buffer cache hits

The Buffer cache hits metric provides the number of buffer cache hits per second in a database. A buffer cache hit occurs when the database is able to avoid reading a block from disk because it is already cached in memory.

Blocks read

The Blocks read metric provides the number of disk blocks read per second as a result of queries in a database.

Transactions committed & rolled back

Transactions committed

The Transactions committed metric provides the number of transactions committed per second. A transaction is committed when its changes are saved to the database.

Transactions rolled back

The Transactions rolled back metric provides the number of transactions rolled back per second. A transaction is rolled back when its changes to the database are reverted, and can only occur prior to the changes being committed. 

Temp bytes

The Temp bytes metric provides the number of temporary bytes written per second. This metric reveals the rate at which the data is being written to temporary files as a result of queries in the database.