Forum Discussion

yonisade's avatar
yonisade
Copper Contributor
Oct 29, 2025

"ALTER DATABASE CURRENT SET ALLOW_SNAPSHOT_ISOLATION ON" does not finish for several hours

I have tried enabling snapshot isolation on several SQL Server instances (2017 and 2022 developer editions) in single user mode with the same huge DB (4 TB) but the command does not finish even after 6 hours...

ALTER DATABASE CURRENT SET ALLOW_SNAPSHOT_ISOLATION ON

Session is waiting on "ENABLE_VERSIONING" and I don't see any noticeable I/O activity on the Windows disk itself.

1 Reply

  • yonisade's avatar
    yonisade
    Copper Contributor
    Dec 30, 2025

    Found the workaround myself:

    https://support.microsoft.com/en-us/topic/sql-server-session-hangs-when-you-try-to-enable-snapshot-isolation-in-sql-server-2016-e7704e62-226e-1844-3d1a-7be9739e0bc5

Resources