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    AnalyticDB:Limits

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    AnalyticDB:Limits

    Last Updated:Jun 13, 2025

    To ensure the stability and security of clusters, AnalyticDB for MySQL is subject to the limits that are described in the following tables.

    Naming limits

    Object

    Naming convention

    Database name

    • The name can be up to 64 characters in length.

    • The name must start with a lowercase letter.

    • The name can contain letters, digits, and underscores (_).

    • The name cannot contain consecutive underscores (_).

    • The name cannot be the same as that of the built-in analyticdb database.

    Table name

    • The name must be 1 to 127 characters in length.

    • The name must start with a letter or underscore (_).

    • The name can contain letters, digits, and underscores (_).

    • The name cannot contain single quotation marks ('), double quotation marks (''), exclamation points (!), or spaces.

    • The name cannot be an SQL reserved keyword.

    Column name

    • The name must be 1 to 127 characters in length.

    • The name must start with a letter or underscore (_).

    • The name can contain letters, digits, and underscores (_).

    • The name cannot contain single quotation marks ('), double quotation marks (''), exclamation points (!), or spaces.

    • The name cannot be an SQL reserved keyword.

    Index name

    The name can be up to 64 characters in length.

    Account name

    • The name must meet the following length requirements:

      • For AnalyticDB for MySQL clusters earlier than V3.1.9.4, the name is 2 to 16 characters in length.

      • For AnalyticDB for MySQL clusters of V3.1.9.4 or later, the name is 2 to 64 characters in length.

    • The name must start with a lowercase letter.

    • The name must end with a lowercase letter or a digit.

    • The name can contain lowercase letters, digits, and underscores (_).

    Password

    • The password must be 8 to 32 characters in length.

    • The password must contain at least three of the following character types: uppercase letters, lowercase letters, digits, and special characters.

    • The password can contain the following special characters: ! @ # ￥ % ^ & * ( ) _ + - =

    Quota limits

    Limits

    Default value

    Description

    Maximum number of clusters that can be purchased within each Alibaba Cloud account

    30

    Each Alibaba Cloud account can purchase up to 30 clusters. To change this value, submit a ticket.

    Maximum number of databases that can be created for each cluster

    2048

    None

    Total number of scale-in, scale-out, upgrade, and downgrade operations on each cluster per day

    12

    None

    Maximum disk usage for a Data Warehouse Edition cluster in reserved mode

    80%

    If the disk usage of a cluster exceeds the threshold, the system sends an alert notification. Each contact can receive up to four alert notifications for disk usage every day.

    90%

    If the disk usage of a cluster exceeds the threshold, the system sends an alert notification, locks the cluster, and denies data write requests. Each contact can receive up to four alert notifications for disk usage every day.

    Maximum amount of hot data for an elastic I/O unit (EIU) within a Data Warehouse Edition cluster in elastic mode

    8 TB

    If the amount of hot data for an EIU exceeds 8 TB, the system locks the cluster and denies data write requests. To resolve this issue, scale out elastic I/O resources.

    Maximum amount of hot data for a set of reserved storage resources within a Data Lakehouse Edition cluster

    8 TB

    If the amount of hot data for a set of reserved storage resources exceeds 8 TB, the system locks the cluster and denies data write requests. To resolve this issue, scale up reserved storage resources.

    Maximum amount of hot data for a set of reserved resources within an Enterprise Edition or Basic Edition cluster

    8 TB

    If the amount of hot data for a set of reserved resources exceeds 8 TB, the system locks the cluster and denies data write requests. To resolve this issue, scale up reserved resources.

    Maximum number of standard accounts that can be created for each cluster

    256

    None

    Maximum number of connections that can be established to each cluster

    No more than 50000 (recommended)

    The number of connections that can be established to an AnalyticDB for MySQL cluster is not limited but varies based on the cluster specifications. Low-specification clusters cannot support excessive connections due to insufficient resources.

    Maximum number of IP address whitelists that can be configured for each cluster

    50

    None

    Maximum number of IP addresses that can be added to each whitelist

    1000

    None

    Maximum number of IP addresses that can be added to whitelists in each cluster

    25000

    None

    Maximum number of partitions in each cluster

    102400

    The total number of partitions in all tables in an AnalyticDB for MySQL cluster cannot exceed 102400. If the number of partitions in a cluster exceeds 102400, you cannot create partitioned tables in the cluster.

    You can execute the following statement to query the number of partitions in all tables in each database:

    SELECT SUM(partition_count) FROM database_name.KEPLER_META_TABLES WHERE table_engine_name IN ("CSTORE", "XUANWU", "XUANWU_V2");

    Maximum number of internal tables that can be created for each Enterprise Edition or Basic Edition cluster

    80000/(Number of shards/Number of sets of reserved resources)

    • The value of Number of shards/Number of sets of reserved resources must be rounded up.
    • Number of sets of reserved resources for Enterprise Edition = Number of reserved resource nodes/3.
    • Number of sets of reserved resources for Basic Edition = Number of reserved resource nodes.

    Methods to increase the maximum number of internal tables:

    Maximum number of internal tables that can be created for each Data Lakehouse Edition cluster or Data Warehouse Edition cluster in elastic mode

    [80000/(Number of shards/Number of EIUs)] × 2

    • The value of Number of shards/Number of EIUs must be rounded up.
    • Number of EIUs for Data Lakehouse Edition = Amount of reserved storage resources/24 ACUs.
    • Number of EIUs for Data Warehouse Edition in elastic mode = Number of sets of elastic I/O resources.

    Methods to increase the maximum number of internal tables:

    Maximum number of tables that can be created for each Data Warehouse Edition cluster in reserved mode that has 1 to 20 node groups

    80000/(Number of shards/Number of node groups)

    The value of Number of shards/Number of node groups must be rounded up.

    You can increase the maximum number of internal tables in a Data Warehouse Edition cluster in reserved mode by adding more node groups.

    Maximum number of external tables that can be created for each cluster

    500000

    None

    Maximum number of columns in each table

    4096

    None

    Maximum number of data entries that can be stored in a single partition of each shard

    2.1 billion

    A single partition of each shard can store up to 2.1 billion data entries.

    Maximum length of comments in each table

    1,024 characters

    None

    Maximum length of comments in each column

    1,024 characters

    None

    Maximum length of a single field in each column

    16 MB

    None

    Maximum length of data that can be written to each row

    16 MB

    None

    Default length of each column

    127 characters

    None

    Maximum number of columns that can be contained in each query

    1024

    None

    Maximum number of items that can be specified in each WHERE clause

    256

    None

    Maximum number of conditions that can be specified in each IN operator

    2000

    Parameter configuration method: SET adb_config MAX_IN_ITEMS_COUNT=3000;.

    A larger value makes an SQL query more complex and may affect query performance.

    Timeout limits

    Operation

    Timeout period (ms)

    Description

    Create a cluster

    600000

    None

    Delete a cluster

    300000

    None

    Scale up a cluster

    600000

    None

    Create a database

    10000

    None

    Delete a database

    10000

    None

    Create a table or view

    10000

    None

    Delete a table or view

    10000

    None

    Truncate a table

    60000

    None

    Add a column

    10000

    None

    Remove a column

    60000

    None

    Update a column

    60000

    None

    Perform a single query

    1800000

    The timeout period for a query. When a query times out, the system ends the query.

    You can modify the timeout period for a query by using the following parameter and hint:

    • Parameter: QUERY_TIMEOUT

    • Hint: query_timeout

    Note

    The system checks queries for timeout errors every 1000 milliseconds. The execution duration of a query must be set to a value that is greater than 1000 milliseconds. Otherwise, the query_timeout hint may not take effect.

    Insert data

    300000

    None

    • INSERT SELECT FROM

    • INSERT UPDATE FROM

    • INSERT DELETE FROM

    24*3600000

    The timeout period for an INSERT statement. When an INSERT statement times out, the system ends the statement.

    You can modify the timeout period for an INSERT statement by using the following parameter and hint:

    • Parameter: INSERT_SELECT_TIMEOUT

    • Hint: insert_select_timeout

    FAQ

    Does the number of shards determined or specified for an AnalyticDB for MySQL cluster indicate the number of shards contained in a table?

    Yes, if the number of shards is 32 for an AnalyticDB for MySQL cluster, each table in the cluster can contain 32 shards.

    How do I query the number of shards?

    • When you create an AnalyticDB for MySQL cluster, the number of shards is determined for the cluster. After you create the cluster, you can change the number of shards for Data Warehouse Edition, but not for Enterprise Edition, Basic Edition, and Data Lakehouse Edition.

      The following tables describe the mappings between the number of shards and cluster specifications.

      Enterprise Edition, Basic Edition, Data Lakehouse Edition, and Data Warehouse Edition in elastic mode

      Number of sets of reserved resources or number of EIUs

      Number of shards

      0 or 1

      64

      2~3

      64

      4~7

      96

      8~15

      256

      16~31

      384

      32~63

      512

      >=64

      1024

      Note

      • Number of sets of reserved resources for Enterprise Edition = Number of reserved resource nodes/3.

      • Number of sets of reserved resources for Basic Edition = Number of reserved resource nodes.

      • Number of EIUs for Data Lakehouse Edition = Amount of reserved storage resources/24 ACUs.

      Data Warehouse Edition in reserved mode

      Number of node groups

      Number of shards

      1

      16

      2~3

      64

      4~7

      96

      8~15

      236

      16~31

      384

      32~63

      512

      >64

      1024

    • You can execute the following statement to query the number of shards for an AnalyticDB for MySQL cluster: SELECT count(1) FROM information_schema.kepler_meta_shards;.