> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Instance Uptime, PostgreSQL

> Instance Uptime for PostgreSQL instances. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

**Card class:** [Non-Hero](/nerve-centre/overview#card-classes-explained)  •  **Category:** [Executive Overview](/nerve-centre/connectors#connectors-by-type)

## At a glance

> **Instance Uptime** is the number of seconds since the PostgreSQL postmaster last started, read from `pg_postmaster_start_time()`. It is the simplest liveness check on the instance: a value that keeps climbing means the server has stayed up, while a sudden drop back towards zero means the postmaster restarted, planned or otherwise. The value is sampled in real time, so an unplanned restart shows up within one refresh cycle.

## What it tracks

The card computes `now() - pg_postmaster_start_time()` and reports the result as an elapsed duration. As long as the postmaster process keeps running the number rises monotonically. A drop is the signal that matters: it means the instance bounced, whether from a planned maintenance restart, an out-of-memory kill of the postmaster, a crash-recovery cycle, or a managed-service failover that promoted a different node. Because the card has no alert threshold of its own (`time window: RT`), it is a context number you read alongside the failover-readiness and health-score cards, which carry the alerts. An uptime that resets without a corresponding maintenance window is worth investigating: pair it with [Failover Readiness](/nerve-centre/kpi-cards/postgresql/failover-readiness) and [PostgreSQL Health Score](/nerve-centre/kpi-cards/postgresql/postgresql-health-score) to confirm the cluster recovered cleanly.

## Reconciling against the source

Reconcile directly with `SELECT pg_postmaster_start_time();` on the instance, or `SELECT now() - pg_postmaster_start_time() AS uptime;` for the elapsed value. On managed services the same restart event appears in the event log: the RDS / Aurora events list (or the CloudWatch `DatabaseConnections` drop), the Cloud SQL operations log, or the Azure Database for PostgreSQL activity log. Note that `pg_postmaster_start_time()` tracks the postmaster, not the host: a managed-service failover that promotes a standby resets this value even though the underlying VM may have been running for far longer.

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### Tracked live in Vortex IQ Nerve Centre

*Instance Uptime* is one of hundreds of KPI pulses Vortex IQ tracks across PostgreSQL and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

[Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.