Search index limits - Tablestore - Alibaba Cloud Documentation Center

This topic describes the limits on search indexes.

Mapping

Item	Maximum value	Description
Number of indexed fields	500	The number of fields that can be indexed.
Array length	256	The maximum number of elements in an array.
Number of nested levels	5	Up to five levels can be nested.
Number of child rows in a nested field	256	The maximum number of child rows that are contained in a nested field.
Number of nested fields	25	The number of child fields that can be nested.
Total length of values in all primary key columns	1,000 bytes	The total length of values in all primary key columns in each row can be a maximum of 1,000 bytes.
Length of the value in a primary key column of the STRING type	1,000 bytes	To index a primary key column of the STRING type, the column value cannot exceed 1,000 bytes in length.
Length of the value in an attribute column of the STRING type if you want to index the column as KEYWORD	4 KB	None.
Length of the value in an attribute column of the STRING type if you want to index the column as TEXT	2 MB	In most cases, the limit is the same as the length limit on an attribute column in a data table. When you perform fuzzy query based on fuzzy tokenization for a TEXT field, if the TEXT field value exceeds 1,024 characters in length, Tablestore truncates the excess characters and discards them, and only tokenizes the first 1,024 characters.
Length of a query string that contains a wildcard	32	The query string can be up to 32 characters in length.
Length of a query string for a prefix query	1,000 bytes	The query string can be up to 1,000 characters in length.

Search

Category	Item	Maximum value	Description
General limits	offset+limit	50000	To increase the number of returned rows, configure the next_token parameter.
	limit	100	Default value: 10. Maximum value: 100. When you call the Search operation to query data of a specified column, the maximum value of the limit parameter can be set to 1000 if the column is contained in search indexes. To increase the limit, submit a ticket.
	timeout	10s	None.
	CU	Unlimited.	None.
	QPS	100,000	The upper limit for lightweight transaction processing is 100,000 queries per second (QPS). To increase the limit, submit a ticket.
	Number of query methods that are specified in a Search call	1024	If complex nested queries are specified in a Search call, query performance is compromised. We recommend that you simplify the queries.
Aggregation and GroupBy	Number of Aggregations at the same level	5	The number of Aggregations is recalculated each time you add a new Aggregation to SubGroupBy.
	Number of GroupBys at the same level	5	The number of GroupBys is recalculated each time you add a new GroupBy to SubGroupBy.
	Number of nested GroupBys	3	The root GroupBy is calculated as a nested level.
	Number of Filters in GroupByFilter	10	None.
	Number of groups returned by GroupByField	2,000	None.
	Number of Ranges in GroupByRange	100	None.
	Number of Ranges in GroupByGeodistance	10	None.

ParallelScan

Category	Item	Description
General limits	offset+limit	When you use parallel scan, you cannot configure the offset and limit parameters. The results that are returned are displayed in chronological order.
	limit	The maximum value is 2,000.
	CU	None.
	QPS	None.
	Maximum number of parallel scan tasks in a ParallelScan call	The value of the MaxParallel parameter. You can call the ComputeSplits operation to obtain the value of the parameter.
	Maximum number of parallel scan tasks	The maximum number of parallel scan tasks is 10. Parallel scan tasks that have the same session ID and the same ScanQuery parameter value are considered one task. For more information, see Parallel scan.

Index

Item	Maximum value	Description
Rate	50,000 rows/s	The first time when data is written to a table or when a large volume of data is written in a short period of time, Tablestore balances loads within a few minutes. The maximum rate of indexing TEXT fields is 10,000 rows/s because this process consumes a large number of CPU resources for tokenization. To increase the limit, submit a ticket.
Synchronization latency	3s	In most cases, the synchronization latency is within 3 seconds. It takes up to 1 minute to initialize a new index.
Number of rows	100 billion	To increase the limit, submit a ticket.
Total size	100 TB	To increase the limit, submit a ticket.

Other limits

The search index feature is available in the following regions: China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Shenzhen), China (Guangzhou), China (Chengdu), China (Hong Kong), Singapore, Australia (Sydney), Indonesia (Jakarta), Japan (Tokyo), Germany (Frankfurt)., UK (London), US (Silicon Valley), US (Virginia), Thailand (Bangkok), India (Mumbai), and Philippines (Manila).

Note

If your business requirements are not met due to the limit, submit a ticket on the Alibaba Cloud official website. When you submit a ticket, you must specify the limits and the limit values. You must also specify the scenarios in which you want to use the new limits and the requirements based on which you want to use the new limits. The requirements that you specify in the ticket are recorded for future development purposes.