This topic describes the limits of Tablestore. Table schemas and row sizes can be tailored to improve performance.

Limits on instances

Item Limit Description
Number of instances created in an Alibaba Cloud account 10

If your business requirements are not met due to the limit, click here to submit a ticket.

Number of tables in an instance 64

The number of base tables and index tables. If your business requirements are not met due to the limit, click here to submit a ticket.

Length of an instance name 3~16 Bytes The name of an instance can contain uppercase and lowercase letters, digits, and hyphens (-). The name must start with a letter and cannot end with a hyphen (-).

The name of the instance cannot contain ali, ay, ots, taobao, or admin.

Limits on tables

Item Limit Description
Length of a table name 1~255 Bytes The name of a table can contain uppercase and lowercase letters, digits, and underscores (_). The name must start with a letter or an underscore (_).
Reserved read CUs and reserved write CUs of a single table 0~100000

If your business requirements are not met due to the limit, click here to submit a ticket.

Limits on columns

Item Limit Description
Column name length 1~255 Bytes The name of a column can contain uppercase and lowercase letters, digits, and underscores (_). The name must start with a letter or an underscore (_).
The number of columns in a primary key 1~4 A primary key can contain one to four primary key columns.
The size of the value in a STRING primary key column 1 KB The size of the value in a STRING primary key column cannot exceed 1 KB.
Size of the value in a STRING attribute column 2 MB The size of the value in a STRING attribute column cannot exceed 2 MB.
Size of the value in a BINARY primary key column 1 KB The size of the value in a BINARY primary key column cannot exceed 1 KB.
Size of the value in a BINARY attribute column 2 MB The size of the value in a BINARY attribute column cannot exceed 2 MB.

Limits on rows

Item Limit Description
Number of attribute columns in a single row Tablestore does not impose limits on the number of attribute columns in a single row. None.
Size of a single row Tablestore does not impose limits on the size of a single row. Tablestore does not impose limits on the total size of column names and column values for a row.

Limits on operations

Operation Limit Description
Number of attribute columns written by one request 1024 During a PutRow, UpdateRow, or BatchWriteRow operation, the number of attribute columns written in a row cannot exceed 1024.
Number of columns specified in columns_to_get in a read request 0~128 The maximum number of columns obtained from a row of data in a read request cannot exceed 128.
Queries per second (QPS) at the table level 10 The QPS for a table is up to 10. For more information about table-level operations, see OperationsSummary.
Count of UpdateTable operations on a single table Upper limit: unlimited

Lower limit: unlimited

The frequency to adjust the count of UpdateTable operations on a single table is limited.
Frequency of UpdateTable operations on a single table Once every two minutes The reserved read/write throughput for a single table can be adjusted once every two minutes at most.
Count of rows read by one BatchGetRow request 100 None.
Number of rows written by one BatchWriteRow request 200 None.
Size of data written by one BatchWriteRow request 4 MB None.
Data returned for one GetRange request 5,000 rows or 4 MB The data returned for a request cannot exceed 5,000 rows or 4 MB. When one of the limits is exceeded, data that exceeds the limits is truncated at the row level. The primary key information of the next row of data is returned.
Data size of an HTTP request body 5 MB None.
Number of filters in one request 10 None.