EXECSYNC

Overview

Occurs during parallel query synchronization phases such as exchange iterator completion and batching. Normal part of parallel execution and rarely actionable by itself.

Key Metrics

Metric	Description
Wait Type	EXECSYNC
Category	Baseline
Severity	LOW

Troubleshooting

1. Identify the source

Use the following query to identify the top queries contributing to EXECSYNC 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 = 'EXECSYNC'
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)