tencent cloud

Feedback

Constraints and Limits

Last updated: 2024-08-02 17:36:10
    TencentDB for SQL Server service only offers instances with bundled licenses, meaning that upon creation, each instance is endowed with the corresponding version's Microsoft SQL Server software licensing authorization. It does not support the provision of licenses brought by users themselves.
    In order to ensure the stability and security of instances, TencentDB for SQL Server has certain restrictions on usage as detailed below.
    TencentDB for SQL Server is available in two editions: single-node edition (formerly Basic Edition) and two-node edition (formerly High Availability/Cluster Edition), each with its own set of features. For more information, see Features and Differences.
    Note:
    TencentDB for SQL Server does not support access to external applications through the database instance; it only permits access to the database instance via external applications.
    If you have other questions about usage restrictions, submit a ticket for assistance.
    Feature
    Two-Node Edition
    Single-Node Edition
    Database version
    2008 R2 Enterprise 2012 Enterprise 2014 Enterprise 2016 Enterprise 2017 Enterprise 2019 Enterprise 2022 Enterprise
    Maximum number of databases (subject to the number of instance CPU cores as described in Constraints and Limits > Database quantity)
    2008 R2 version: 300
    2012, 2014, and 2016 versions: 300
    2017, 2019, and 2022 versions: 100
    400
    Maximum number of database accounts
    Unlimited
    Unlimited
    Database creation
    Supported
    Supported
    User/Login account creation and deletion
    Supported
    Supported
    SA account creation
    Not supported
    Supported
    Database authorization
    Supported
    Supported
    Database-level DDL trigger
    Supported
    Supported
    Thread killing permission
    Supported
    Supported
    SQL profiler
    Supported
    Supported
    Publish/Subscribe
    Supported
    Not supported
    Optimization advisor
    Not supported
    Supported
    Linked server
    For a detailed explanation, please refer to Limitations of the Linked Server Features.
    Distributed transaction
    Only supported by two-node local disk instances
    Not supported
    Change data capture (CDC)
    Supported
    Supported
    Change tracking (CT)
    Supported
    Supported
    Windows domain account login
    Not supported
    Not supported
    Email
    Not supported
    Not supported
    SQL Server Integration Services (SSIS)
    Supported
    Supported
    SQL Server Analysis Services (SSAS)
    Not supported
    Not supported
    SQL Server Reporting Services (SSRS)
    Not supported
    Not supported
    R language service
    Not supported
    Not supported
    Common Language Runtime (CLR) integration
    Not supported
    Not supported
    Async messaging
    Not supported
    Not supported
    Policy management
    Not supported
    Not supported

    Database quantity

    Note:
    For a two-node (formerly High Availability/Cluster Edition) instance, if you set max worker threads to the default value 0, you can create no more than 100 databases. To create more databases, you must set this parameter to 20,000 as instructed in Setting Instance Parameters.
    If the instance only has one CPU core, we recommend that you keep the database quantity limit at 70 to guarantee instance stability.
    SQL Server 2008 R2 Enterprise instances don't support lifting the database quantity limit, which is 70. The limit in other SQL Server instances is subject to the number of instance CPU cores as calculated below:
    Two-node (formerly High Availability Edition) 2012 Standard/Enterprise 2014 Standard/Enterprise 2016 Standard/Enterprise Maximum number of databases:
    
    Extract the square root of the CPU core quantity, round it to one decimal place, multiply the result by 40, and add the product to 80 to get the value X. The smaller value between X and 300 is the maximum number of databases. For example, you can create up to 160 databases in a 4-core 16 GB MEM SQL Server 2014 Enterprise instance.
    Two-node (formerly Cluster Edition) 2017 Enterprise 2019 Enterprise 2022 Enterprise
    The maximum number of databases is related to the instance CPU. The maximum number of databases for instances with 8-core CPU or less is 80, and the maximum number of databases for instances with 8-core CPU or above is 100.
    Single-node (formerly Basic Edition) 2008 R2 Enterprise 2012 Enterprise 2014 Enterprise 2016 Enterprise 2017 Enterprise 2019 Enterprise
    2022 Enterprise Maximum number of databases:
    
    Extract the square root of the CPU core quantity, round it down to the nearest integer, and multiply the result by 100 to get the value N. The smaller value between N and 400 is the maximum number of databases. For example, you can create up to 200 databases in a 4-core 16 GB MEM SQL Server 2017 Enterprise instance.
    Table of instance CPU core quantity and corresponding database quantity limit
    Database quantity limit for two-node edition (formerly High Availability/Cluster Edition)
    Database quantity limit for single-node edition (formerly Basic Edition)
    CPU cores
    Two-node 2008 R2/2012/2014/2016 Enterprise
    Two-node 2017/2019/2022 Enterprise
    1
    70
    70
    2
    136
    176
    4
    160
    200
    8
    193
    233
    12
    218
    258
    16
    240
    280
    24
    275
    315
    32
    300
    340
    48
    300
    340
    64
    300
    340
    96
    300
    340
    Number of CPU Cores
    Single Node 2008 R2 Enterprise Edition
    Single-node 2012/2014/2016/2017/2019/2022 Enterprise Edition
    2
    80
    100
    4
    80
    200
    8
    80
    200
    12
    80
    300
    16
    80
    400
    24
    80
    400
    32
    80
    400
    48
    80
    400
    64
    80
    400

    Linked Server Limitations

    Linked servers are not supported between other clouds or self-built environments and Tencent Cloud and are only supported for a Tencent Cloud private network. However, within the TencentDB for SQL Server instance architecture, there are the following restrictions:
    1. Cross-Architecture Scenarios
    Cross-Architecture Direction
    Description
    Two-node instance → single-node instance
    Not supported.
    Single-node instance → two-node instance
    Not supported.
    Local disk instance → cloud disk instance
    Not supported.
    Cloud disk instance → local disk instance
    Not supported.
    2. Between Two-Node Instances
    Cross-Architecture Direction
    Description
    Two-node local disk instance → two-node local disk instance
    Interconnection is supported between domestic regions, and interconnection is supported between overseas regions, but not between domestic and overseas regions.
    Two-node cloud disk instance → two-node cloud disk instance
    Only interconnection within the same region is supported.
    3. Between Single Node Instances
    Interconnection is supported only when the source and target are the same instance.
    Contact Us

    Contact our sales team or business advisors to help your business.

    Technical Support

    Open a ticket if you're looking for further assistance. Our Ticket is 7x24 avaliable.

    7x24 Phone Support