Azure SQL Database
An Azure relational database service.
3,496 questions
What is the PERSISTED_VERSION_CLEANER process?
Роман Губ'як
1
Reputation point
I would like to know about this process:
- What is its purpose?
- When is it running?
- What does it perform?
- Why does it use a lot of CPU&DATAIO?
I cannot find any documentation about PERSISTED_VERSION_CLEANER.
{count} votes
-
KalyanChanumolu-MSFT 8,251 Reputation points Microsoft Employee
2020-09-16T10:47:31.947+00:00 @Роман Губ'як Are you facing any specific issues?
Is this blocking any of your queries?I will try and get more information on this internally from the product group.
Sign in to comment
2 answers
Sort by: Oldest
-
KalyanChanumolu-MSFT 8,251 Reputation points Microsoft Employee
2020-09-16T13:57:49.37+00:00 @Роман Губ'як , I have checked this internally and as @Tom Phillips pointed out, this is part of the implementation of accelerated database recovery. It uses page versioning to reduce recovery time on failovers. This is turned on by default on Azure SQL Database
If you are seeing abnormally high waits on this, please reach out to Azure Support.
-
Роман Губ'як 1 Reputation point
2020-09-23T05:03:17.07+00:00 How to disable ADR temporarily? I cannot create index, change nullable column to nonnullable and perform other schema changes, because of it. I discovered in sp_who2 that my process is suspended most of the time, however that cleaner is always running.
RatheeshKNair 6 Reputation points2020-09-23T05:32:49.057+00:00 ALTER DATABASE DB_Name SET ACCELERATED_DATABASE_RECOVERY = OFF
Роман Губ'як 1 Reputation point2020-09-23T13:04:06.083+00:00 This does not work. See screenshot.
AmeliaGu-MSFT 13,891 Reputation points Microsoft Vendor2020-09-24T01:27:53.4+00:00 Hi @Роман Губ'як ,
ADR is new in SQL Server 2019. SQL Server 2014 RTM (12.0.2000.8) does not support ADR.
In addition, you can use the following query to check if ADR is enabled:SELECT name , is_accelerated_database_recovery_on FROM SYS.DATABASES WHERE name = 'dbname'is_accelerated_database_recovery =1 means ADR is enabled.
Best Regards,
Amelia
Роман Губ'як 1 Reputation point2020-09-24T05:47:24.883+00:00 Now I am confused. ADR isn't supported but it's turned on. It's turned on, but I cannot disable it because it's not supported. I didn't mention, that I use Azure SQL Database (just in case if it makes a difference).
AmeliaGu-MSFT 13,891 Reputation points Microsoft Vendor2020-09-24T09:42:36.403+00:00 Hi @Роман Губ'як ,
Sorry that I have no environment to test for you.
According to this article, ADR is enabled by default in Azure SQL Database and Azure SQL Managed Instance and disabling ADR for either product is not supported.Best Regards,
Amelia
Роман Губ'як 1 Reputation point2020-09-24T12:57:19.927+00:00 Ha! Article has been updated after I asked the question. https://github.com/MicrosoftDocs/azure-docs/commits/52d54f432e1a91d5e8c417c72f6daa0a77bb16a7/articles/azure-sql/accelerated-database-recovery.md
Nothing to say. It's just wasting of time.Thank you everyone, who spent his time here for me!
Sign in to comment
Hi @Роман Губ'як ,
Did the answers help you?
If you find any post in the thread is helpful, you could kindly accept it as answer. This would benefit the community, and encourage the community member to keep working on your issues.
Best Regards,
Amelia