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Lindorm:Quotas and limits

Last Updated:Jun 09, 2023

To ensure the normal running of your Lindorm instances, read the quotas and limits described in this topic before you use Lindorm.

General limits

Note

The general limits described in this section apply to Lindorm clusters and single-node Lindorm instances.
Additional limits on data requests and objects are posed for single-node Lindorm instances. For more information, see Additional limits for single-node Lindorm instances.

Naming conventions

The following table describes the naming conventions for different objects in Lindorm.


Object	Naming convention
User name	The name can be 4 to 15 characters in length. The name can contain digits, letters, hyphens (-), and underscores (_). The following reserved words cannot be used as user names: system, anonymous, and lindorm.
Namespace name	The name can be 4 to 16 characters in length. The name can contain digits, letters, hyphens (-), and underscores (_). The following reserved words cannot be used as namespace names: lindorm, default, and global.
Table name	The name can be 1 to 255 characters in length. The name can contain digits, letters, hyphens (-), and underscores (_).
Column name	The name can be 1 to 255 characters in length.

Limits on objects


Object	Limit
Primary key column	The total length of all primary keys cannot exceed 2 KB. A table can contain up to five primary key columns. Only the last primary key of a table can be of the varbinary data type. We recommend that you do not use an auto-increment field or a column with fewer rows as the first primary key column.
Non-primary key column	Non-primary dynamic columns support only the varbinary data type. The total length of all non-primary key columns cannot exceed 2 MB.
Index	A database can have up to five index tables. We recommend that you do not use an auto-increment field, a time field, or a column with fewer rows as an index.
Table	The name of a table cannot be modified after the table is created. A table can contain up to three column families.

Limits on data requests


Request content	Limit
Data writing	Up to 64 MB of data can be written to Lindorm at a time. Up to 2,000 rows can be written to Lindorm at a time. If more than 50 files are stored in a single region, the write latency increases. Note For more information about how to query the number of files stored in a region, see Overview. If more than 100 files are stored in a single region, errors may occur. If more than 200 files are stored in a single region, data cannot be written to the region until the number of files in the region is less than 200.
Data deletion	Up to 2,000 rows can be deleted at a time.
Data reading	Up to 2,000 values can be specified for the IN operator in SQL queries. Up to 2,000 rows or 16 MB of data can be read at a time. You must specify the first primary key column or the first index column when you query data. Note If you do not specify the first primary key column or the first index column in a query request, the query scans all data in the table. By default, this kind of inefficient query requests may be rejected. If you must perform a query without specifying the first primary key or first index column, see the troubleshooting section of SELECT. When you use the `ORDER BY` clause in SQL queries to sort data, you must specify the LIMIT conditions When you use the `ORDER BY` clause in SQL queries to sort data, the values specified for LIMIT and OFFSET cannot be larger than 10000. When you use the `DISTINCT` clause in SQL queries for data deduplication, the number of values specified for `DISTINCT` cannot exceed 1,000. Otherwise, errors may occur. When you use the `GROUP BY` clause in SQL queries, the number of groups cannot exceed 1,000 for a single instance. Otherwise, errors may occur.

Additional limits for single-node Lindorm instances

Important

Single-node Lindorm instances can be used only for functional tests and cannot be used for stress tests or production.
The SLA and data reliability of single-node Lindorm instances are not guaranteed.
Single-node Lindorm instances cannot be upgraded to Lindorm clusters.

Limits on objects


Object	Limit
Namespace	A single-node Lindorm instance can have up to three namespaces. A namespace can contain up to 20 tables.
Connection	Up to 2,000 connections can be established for a single-node Lindorm instance.

Limits on data requests


Request type	Limit
Data request	When the single-node Lindorm instance has 2 CPU cores, the resources consumed by read requests cannot exceed 10,000 CUs. When the single-node Lindorm instance has 4 CPU cores, the resources consumed by read requests cannot exceed 20,000 CUs. When the single-node Lindorm instance has 8 CPU cores, the resources consumed by read requests cannot exceed 50,000 CUs. The KV value cannot exceed 2 MB. Up to 500 rows can be read or written at a time. The amount of data that you can read or write by a single request cannot exceed 16 MB.