PAGEIOLATCH_EX

Overview

Occurs when a task waits for a data page to be written from the buffer pool to disk (exclusive latch). High durations indicate write latency on the storage subsystem.

Key Metrics

Metric	Description
Wait Type	PAGEIOLATCH_EX
Category	Io
Severity	HIGH

Troubleshooting

1. Identify the source

Use the following query to identify the top queries contributing to PAGEIOLATCH_EX waits:

SELECT TOP 10
 [Wait Type] = wait_type,
 [Wait Seconds] = wait_time_ms / 1000,
 [Wait Count] = waiting_tasks_count,
 [Avg Wait Ms] = wait_time_ms / NULLIF(waiting_tasks_count, 0)
FROM sys.dm_os_wait_stats
WHERE wait_type = 'PAGEIOLATCH_EX'
ORDER BY wait_time_ms DESC;

2. Related diagnostics

• Review overall wait statistics using sys.dm_os_wait_stats
• Check session-level waits via sys.dm_exec_session_wait_stats
• Correlate with sys.dm_exec_requests for blocking analysis

See Also

• sys.dm_os_wait_stats (Transact-SQL)
• sys.dm_exec_session_wait_stats (Transact-SQL)
• sys.dm_os_waiting_tasks (Transact-SQL)