# Metrics and performance
Source: https://docs.infraista.com/en/data-storage/databases/metrics-and-performance



## Usage at a glance [#usage-at-a-glance]

A database's **Overview** shows its CPU, memory and storage use against its plan, updated every minute.
Storage beyond the plan is billed per GB-month; the Overview says how much and suggests a larger plan.

## Metrics [#metrics]

The **Metrics** tab charts connections, queries and traffic, sampled every 5 minutes:

* **Connections**: open client connections, against the number allowed;
* **Queries / sec** and **Transactions / sec**;
* **Cache hit rate**: reads served from memory;
* **Traffic** in and out;
* **Resources**: CPU, memory and storage against the plan, with CPU and memory live for the last 15
  minutes.

Graphs appear about 10 minutes after the database starts running.

The Metrics tab also shows:

* **Sessions**: clients connected right now, with their state and query. **Cancel query** stops a
  statement (the session stays connected); **End session** disconnects the client and rolls back its
  open transaction.
* **Configuration**: the engine's settings (read-only).

## Performance Insights [#performance-insights]

**Performance Insights** shows, live from the database server, what is running and what costs the most.
It covers all databases on the server by default; pick one to see its tables, indexes and statements.

* **What's running now**: active queries; those running longer than 30 seconds are highlighted. To
  cancel one, use **Sessions** on the Metrics tab.
* **Busiest** and **largest databases** on the server.
* **Top queries**: the statements that cost the most, with values replaced by `?`, sorted by **Total
  time**, **Per run** or **Most runs**. Statements read without an index are flagged.
* **Index health**: indexes that are never used, or already covered by another one. They slow down
  writes and use disk.

## Related [#related]

* [Data Explorer and SQL console](/en/data-storage/databases/data-explorer-and-sql-console)