This topic describes the limits of Tablestore.
Instances
Item | Limit | Description |
Number of Instances | 10 | If your business requirements are not met due to the limit, submit a ticket. |
Instance name | Unique within a region | Instance naming conventions:
|
Number of tables in an instance | 64 | The number of tables is the sum of the numbers of data tables, secondary indexes, time series tables, Lastpoint indexes, and analytical stores. If your business requirements are not met due to the limit, submit a ticket. Important A time series table consists of a time series metadata table and a time series data table. Therefore, a time series table is equivalent to two tables. |
Wide Column model
Item | Limit | Description |
Name of a data table | Unique within an instance | Naming conventions for data tables:
|
Number of primary key columns | 1~4 | The first primary key column is the partition key. |
Data types of primary key columns | String, Integer, and Binary |
|
Number of attribute columns | None | Tablestore does not impose a limit on the number of attribute columns. If you attempt to read a row in which an excessive number of attribute columns are included, such as hundreds of thousands of attribute columns, you may fail to read the row due to timeout. In this case, you must specify the attribute columns that you want to read or read data by page. We recommend that you specify up to 10,000 attribute columns. |
Data types of attribute columns | String, Integer, Double, Boolean, and Binary |
|
Number of predefined columns | 0~32 | Predefined columns are non-primary key columns whose names and types are defined when a data table is created. Predefined columns can be used as the fields of a secondary index that is created for the data table. |
For information about more limits on the Wide Column model, see Limits on the Wide Column model.
TimeSeries model
Item | Limit | Description |
Name of a time series table | Unique within an instance | Naming conventions for a time series table:
|
For information about more limits on the TimeSeries model, see Limits on the TimeSeries model.
Search indexes
Item | Limit | Description |
Number of search indexes | None | We recommend that you create only one search index that contains all fields that you want to retrieve. |
Number of index fields | 1000 | None |
Number of rows | 100 billion | If your business requirements are not met due to the limit, submit a ticket. |
Total size | 100 TB | If your business requirements are not met due to the limit, submit a ticket. |
Read or write rate | 50,000 rows/s |
If your business requirements are not met due to the limit, submit a ticket. |
Synchronization latency | 3s |
|
Max versions | Not supported | None |
For information about more limits on search indexes, see Search index limits.
Secondary indexes
Item | Limit | Description |
Number of secondary indexes | 5 | If your business requirements are not met due to the limit, submit a ticket. |
Number of index fields | 36 |
|
Max versions | Not supported | None |
For information about more limits on secondary indexes, see Secondary index limits.
SQL query
Item | Limit | Description |
Mapping table names and column names | Cannot be the same as a reserved word or keyword | Naming conventions for a mapping table and a column in a mapping table:
|
Execution duration of a single SQL statement | 30 s | The execution duration of a single SQL statement is related to the complexity of the SQL statement and the amount of data in the table. The maximum duration is 30 seconds. If the maximum duration is exceeded, the system returns an error. |
Amount of data for a single scan | 128 MB or 100,000 rows | The maximum number of rows for a single scan is 100,000 or the maximum amount of data for a single scan is 128 MB. If the upper limit is exceeded, the system returns an error. |
For more information, see SQL limits.