Constraints and limits
Data consistency
Because of the read/write splitting architecture, a Doc may not be immediately available for Retrieve Doc and Get Doc operations after an Insert Doc, Update Doc, or Insert or Update Doc operation. Similarly, a Doc may not be immediately hidden from Retrieve Doc and Get Doc operations after a Delete Doc operation.
DashVector ensures eventual data consistency. All Doc operations are strictly executed in the order they are received.
Free instance (cluster) limits
To adjust the limits for free instances (clusters), such as the number of collections, maximum number of Docs, or Queries Per Second (QPS) limits, or if you have any requests, feedback, or need technical support, contact us through the following channels:
Official DingTalk group: 25130022704
Technical support email: dashvector@service.aliyun.com
Limit | Condition |
Number of free clusters per UID | 1 |
Number of collections per free cluster | 2 |
Free cluster usage duration | 1 month. After the cluster expires or is manually released, you can request to create a new free cluster. |
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Collections in a free cluster have a fixed amount of storage space. The maximum number of Docs and the QPS for Retrieve Doc adjust dynamically based on the vector dimensions. The current maximum QPS for free instances is 30. Use the following table to estimate the maximum number of Docs and the maximum QPS for Retrieve Doc:
Vector dimensions | Theoretical maximum number of Docs in a free collection | Theoretical maximum QPS for Retrieve Doc in a free collection |
64 | 2,400,000 | 30 |
128 | 1,200,000 | 30 |
256 | 600,000 | 30 |
512 | 300,000 | 15 |
768 | 200,000 | 10 |
1024 | 150,000 | 7 |
1536 | 100,000 | 5 |
2048 | 75,000 | 3 |
4096 | 37,500 | 1 |
8192 | 18,750 | 1 |
16384 | 9,375 | 1 |
20000 | 7680 | 1 |
Paid instance (cluster) limits
The capacity and QPS of paid clusters do not have predefined hard limits. Instead, their upper limits are determined by factors such as the selected cluster specifications, data volume, and vector dimensions. For more information, see Product specifications.
A paid cluster can have a maximum of 32 collections. The number of partitions you can create increases with the instance specifications and is independent of the number of collections.
For example, a P.2xlarge cluster can have up to 2,048 partitions. If there is only one collection, that collection can have 2,048 partitions. If there are 32 collections, each collection can have an average of 64 partitions.
Instance type | Specifications | Number of collections | Number of partitions |
Compute-optimized | P.small | 32 | 512 |
P.large | 32 | 1024 | |
P.2xlarge | 32 | 2048 | |
P.4xlarge | 32 | 4096 | |
P.8xlarge | 32 | 8192 | |
P.16xlarge | 32 | 16384 | |
Storage-optimized | S.small | 32 | 512 |
S.large | 32 | 1024 | |
S.2xlarge | 32 | 2048 | |
S.4xlarge | 32 | 4096 | |
S.8xlarge | 32 | 8192 | |
S.16xlarge | 32 | 16384 | |
Serverless | - | 32 | 128 |
General limits
Limit | Limitations |
Maximum number of API keys per UID | 3 |
Collection name | Must consist of uppercase and lowercase letters, digits, underscores (_), and hyphens (-). The length must be from 3 to 32 characters. |
Collection vector dimension limit | (1, 20000] |
Partition name | Must consist of uppercase letters, lowercase letters, digits, and underscores (_). The length must be from 3 to 32 characters. |
Field name | Must consist of uppercase letters, lowercase letters, digits, and underscores (_). The length must be from 1 to 32 characters. |
Doc ID | Must consist of uppercase letters, lowercase letters, digits, and the following characters: _, -, !, @, #, $, %, +, =, .. The length must be from 1 to 64 characters. |
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Maximum TopK for Retrieve Doc | 1024 |
Maximum group_count for grouped vector search | 64 |
Maximum group_topk for grouped vector search | 16 |
Maximum body size for all API requests | 2 MB. A size of 50 KB or less is recommended. |
Maximum number of fields | 1,024. 64 or fewer is recommended. |
Sparse feature | The number of non-zero values cannot exceed 4,095. The index must be between 0 and 4,294,967,295, inclusive. |