Tablestore:Search index limits

Item

Limit

Description

Name of a secondary index

Unique within an instance

Naming conventions for a secondary index:

• The name must be 1 to 255 bytes in length and can contain letters, digits, and underscores (_). The name is case-sensitive.

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

Number of secondary indexes

5

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

Number of index fields

36

• The primary key of a secondary index consists of index columns and all primary key columns of the data table for which the secondary index is created. The primary key consists of up to eight columns, among which up to four columns are index columns. Index columns can be the primary key columns or predefined columns of the data table.

• A secondary index can contain up to 32 attribute columns, which are the predefined columns of the data table.

Data types supported by index columns

String, Integer, and Binary

• String: a UTF-8-encoded string that does not exceed 1 KB in length.

• Integer: a 64-bit signed integer that is 8 bytes in length.

• Binary: binary data that does not exceed 1 KB in length.

Data types supported by attribute columns

String, Integer, Double, Boolean, and Binary

• String: a UTF-8-encoded string that does not exceed 2 MB in length.

• Integer: a 64-bit signed integer that is 8 bytes in length.

• Double: a 64-bit Double value that is 8 bytes in length.

• Boolean: True or False that is 1 byte in length.

• Binary: binary data that does not exceed 2 MB in length.

Item

Limit

Description

Index column

Columns except auto-increment primary key columns

The first primary key column of an index table cannot be an auto-increment primary key column.

Operation on data in index tables

Read-only

You can only read data from index tables. You cannot write data to index tables.

Max versions

Not supported

None

Time to live (TTL)

Supported

You must prohibit updates to a data table to ensure that the TTL of the data table is the same as the TTL of the index table that is created for the data table.

Stream

Not supported

None

Query from data tables

Not supported

Queries from data tables are required.