Database Query Functions

Overview

Database query functions provide deep visibility into SQL and NoSQL database performance through Netdata's Live tab. They help you identify problematic queries, detect deadlocks, and understand error patterns—all from the Netdata dashboard.

Capability	Description
Top Queries	Identify the most expensive queries by execution time, I/O, rows processed, or other metrics
Running Queries	See currently executing queries in real-time
Deadlock Detection	View the latest detected deadlock with full transaction details
Error Attribution	Correlate SQL errors with the queries that caused them

Supported Databases

Database	Top Queries	Running Queries	Deadlock Info	Error Info	Integration Docs
ClickHouse	✅	-	-	-	ClickHouse
CockroachDB	✅	✅	-	-	CockroachDB
Couchbase	✅	-	-	-	Couchbase
Elasticsearch	✅	-	-	-	Elasticsearch
MongoDB	✅	-	-	-	MongoDB
Microsoft SQL Server	✅	-	✅	✅*	MSSQL
MySQL	✅	-	✅	✅*	MySQL
MariaDB	✅	-	✅	✅*	MariaDB
Percona Server	✅	-	✅	✅*	Percona
Oracle Database	✅	✅	-	-	Oracle
PostgreSQL	✅	✅	-	✅**	PostgreSQL
ProxySQL	✅	-	-	-	ProxySQL
Redis	✅	-	-	-	Redis
RethinkDB	-	✅	-	-	RethinkDB
YugabyteDB	✅	✅	-	-	YugabyteDB

* Error Info is integrated directly into Top Queries results—each query row shows its associated errors.

** PostgreSQL error info requires pg_stat_monitor (Percona). The collector auto-detects and uses it when available.

Function Types

Top Queries

Retrieves accumulated query statistics over a time window. These are aggregated metrics (total calls, total time, average time, etc.) from the database's query statistics infrastructure—not real-time snapshots.

Filter options vary by database but typically include:

• Execution time (total, average)
• Call count
• Rows processed (read, written, returned)
• I/O metrics (logical reads, physical reads)
• Resource usage (CPU, memory, locks)

The number of queries returned is configurable (default: 500). This is a two-stage process:

1. Server-side: Database returns the top N queries ranked by your chosen metric
2. Client-side: UI can further sort, filter, and explore the returned data

Running Queries

Shows currently executing queries at the moment of request. Essential for diagnosing stuck queries, long-running transactions, or unexpected load.

Supported: CockroachDB, Oracle, PostgreSQL, RethinkDB, YugabyteDB

Deadlock Info

Displays the most recently detected deadlock—not a historical list. When a new deadlock occurs, it replaces the previous one.

Supported: MySQL/MariaDB/Percona, Microsoft SQL Server

Information provided:

• Deadlock timestamp and ID
• Participating transactions
• Victim transaction (rolled back)
• Query text and lock details
• Wait resource

Error Info

Shows recent SQL errors from the database's error history. Error attribution is embedded directly in Top Queries results—each query row includes error details when available.

Supported: MySQL/MariaDB/Percona, Microsoft SQL Server, PostgreSQL (with pg_stat_monitor)

Attribution status values:

• enabled — Error details available for this query
• no_data — No recent errors for this query
• not_enabled — Error tracking not configured
• not_supported — Database version lacks required features

Security Considerations

Query Text Exposure

Some databases normalize queries (replacing literals with placeholders), while others show actual values that may contain sensitive data:

Database	Query Text
ClickHouse	Normalized
CockroachDB	⚠️ Raw
Couchbase	⚠️ Raw
Elasticsearch	⚠️ Raw
MongoDB	⚠️ Raw
Microsoft SQL Server	⚠️ Raw
MySQL/MariaDB/Percona	Normalized (Top Queries), ⚠️ Raw (Deadlock)
Oracle	⚠️ Raw
PostgreSQL	Normalized
ProxySQL	Normalized
Redis	⚠️ Raw
RethinkDB	⚠️ Raw
YugabyteDB	⚠️ Raw

Legend:

• Normalized: Literals replaced with placeholders (SELECT * FROM users WHERE id = ?)
• ⚠️ Raw: May contain actual values (SELECT * FROM users WHERE id = 12345)

:::caution

Error messages may contain sensitive values regardless of query normalization. Ensure appropriate access controls are in place.

:::

Recommendations

1. Disable unneeded functions — Each integration supports configuration options to disable specific functions
2. Use Netdata Cloud access controls — Assign users to appropriate Rooms and Roles
3. Use dedicated database users — Grant only the permissions required for monitoring

Getting Started

Each database requires specific setup. Click the integration link in the table above for:

• Prerequisites and permissions required
• Configuration options
• Available metrics and columns
• Database-specific notes

Related Documentation

• Live View
• Processes Function