> ## 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.

# Query Latency p50 (ms), MariaDB

> Query Latency p50 (ms) for MariaDB 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:** [Performance](/nerve-centre/connectors#connectors-by-type)

## At a glance

> **Query Latency p50 (ms)** is the median statement execution time on the instance: half of all queries in the window finished faster than this figure, half slower. It is the "typical experience" latency, the number that tells a DBA whether the everyday query path is healthy, in contrast to the tail percentiles that surface the worst cases. A stable, low p50 means the common queries are being served from the buffer pool and indexes are doing their job.

## What it tracks

The card reports Query Latency p50 (ms) for the selected period, computed as the median of statement execution times rather than a mean, so a few very slow queries cannot drag the headline up. The figure is read from MariaDB's statement timing instrumentation (the `performance_schema` statement-latency summaries, reported in picoseconds and converted to milliseconds) over the `RT/5m` window: a live reading backed by a rolling five-minute distribution. Because it is the median, p50 moves only when the bulk of the workload slows down, which usually points to a broad cause such as buffer-pool pressure, a missing index on a hot table, or general resource contention, rather than a single rogue query. The card carries no alert threshold; p50 is read against its own baseline and alongside the tail percentiles ([p95](/nerve-centre/kpi-cards/mariadb/query-latency-p95-ms) and [p99](/nerve-centre/kpi-cards/mariadb/query-latency-p99-ms)). A p50 that rises while p95 stays flat means the whole workload has shifted slower; a flat p50 with a rising p95 means the typical query is fine but the tail is suffering.

## Reconciling against the source

Confirm against MariaDB's own timing data with `SELECT * FROM performance_schema.events_statements_summary_by_digest ORDER BY AVG_TIMER_WAIT DESC`, which gives per-query timing, or read the latency distribution from `sys.statement_analysis`. On a managed service, compare against the provider's query-latency metric on the managed-database console. Small differences are expected from window alignment and the median-versus-mean distinction.

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### Tracked live in Vortex IQ Nerve Centre

*Query Latency p50 (ms)* is one of hundreds of KPI pulses Vortex IQ tracks across MariaDB 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.