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
The following table describes the naming limits for AnalyticDB for MySQL Data Lakehouse Edition (V3.0) and Data Warehouse Edition (V3.0).
Object | Naming convention |
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Database name |
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Table name |
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Column name |
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Index name | The name can be up to 64 characters in length. |
Account name |
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Password |
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Quota limits
The following table describes the quota limits for AnalyticDB for MySQL Data Lakehouse Edition (V3.0) and Data Warehouse Edition (V3.0).
Limits | Default value | Description |
---|---|---|
Maximum number of clusters that can be purchased within each Alibaba Cloud account | 64 | None |
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 cluster in reserved mode for Cluster Edition | 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 cluster in elastic mode for Cluster Edition | 4 TB | If the amount of hot data for an EIU exceeds 4 TB, the system locks the cluster and denies data write requests. For information about how to resolve this issue, see What do I do if a cluster is locked? |
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 | 5000 | None |
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 | None |
Maximum number of tables that can be created for each cluster that has 1 to 20 node groups in reserved mode for Cluster Edition | 80000/(Number of shards/Number of node groups) |
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Maximum number of internal tables that can be created for each cluster in elastic mode for Cluster Edition | [80000/(Number of shards/Number of EIUs)] × 2 |
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Maximum number of external tables that can be created for each cluster in elastic mode for Cluster Edition | 500000 | None |
Maximum number of columns in each table | 4096 | None |
Maximum length of comments in each table | 1024 characters | None |
Maximum length of comments in each column | 1024 characters | None |
Maximum length of 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 | The following SQL statement can be used to modify this value based on your business requirements: SET adb_config MAX_IN_ITEMS_COUNT=3000; . A larger value makes an SQL query more complex and may affect query performance. |
Timeout limits
The following table describes the timeout limits for AnalyticDB for MySQL Data Lakehouse Edition (V3.0) and Data Warehouse Edition (V3.0).
Operation | Timeout period (unit: milliseconds) | Description |
---|---|---|
Create a cluster | 600,000 | None |
Delete a cluster | 300,000 | None |
Scale up a cluster | 600,000 | None |
Create a database | 10,000 | None |
Delete a database | 10,000 | None |
Create a table or view | 10,000 | None |
Delete a table or view | 10,000 | None |
Truncate a table | 60,000 | None |
Add a column | 10,000 | None |
Remove a column | 60,000 | None |
Update a column | 60,000 | None |
Perform a single query | 1,800,000 | 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:
Note The system checks timeout queries every 1,000 milliseconds. Therefore, the maximum execution duration of a query must be set to a value greater than 1,000 milliseconds. Otherwise, the query_timeout hint may not take effect. |
Insert data | 300,000 | None |
| 24 × 3,600,000 | 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:
|