General Specifications

Updated on 2025-02-27 GMT+08:00

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[Rule] Database valuable features

**Table 1** Recommended database valuable features
Category	Feature List	Description
Table type	Partitioned table	Data partitioning.
Storage engine	Row store	Stores tables by row, which is recommended in the point query and a scenario with many add, delete, and alter operations.
Transaction	Transaction block	Explicitly starts a transaction.
Transaction	Single-statement transaction	Does not explicitly start a transaction. A single statement is a transaction.
Deployment	One primary and multiple standby DNs	One primary DN and multiple standby DNs, ensuring data backup and disaster recovery.
Security	Transparent data encryption	Supports database-level storage encryption. Upper-layer services are unaware of the encryption.
Data type	Integer	TINYINT, SMALLINT, INTEGER, and BIGINT
	Arbitrary-precision	NUMERIC/DECIMAL
	Floating-point	REAL/FLOAT4, DOUBLE PRECISION/FLOAT8, and FLOAT
	Boolean	Boolean
	Fixed-length character	CHAR(n)
	Variable-length character	VARCHAR(n), NVARCHAR2(n), and TEXT
	Time	DATE, TIME, TIMETZ, TIMESTAMP, TIMESTAMPTZ, SMALLDATETIME, INTERVAL, and REALTIME
	Binary	BYTEA (variable-length binary)
	Bit string	BIT(n) and VARBIT(n)
Function	String function	String data type processing function.
	Binary string function	Binary string type processing function.
	Numeric operation function	Numeric type processing function.
	Time and date processing function	Time and date type processing function.
Index	Primary key or unique index	Single-column or multi-column primary key or unique index.
Index	B-tree index	Index type.

[Rule] Recommended best practices for database usage

**Table 2** Recommended best practices for database usage
No.	Item	Recommended Value
1	Optimal number of long connections to the database	For details, see the default configuration of GUC parameter max_connections in the corresponding hardware specifications.
2	Maximum data volume on a single physical node	16 TB (Determine the capacity based on the backup and restoration specifications.)
3	Number of active databases	1
4	Total number of database tables and indexes	10000 (It is recommended that the number of tables in a single schema be less than or equal to 200.) NOTE: The value is only a recommended value. You need to plan the value based on the disk capacity and customer services. Theoretically, the maximum value is 2³².
5	Optimal number of columns in a single table	< 50
6	Optimal number of indexes in a table	< 5
7	Optimal number of composite indexes in a table	< 3
8	Optimal number of columns in a single composite index	< 5
9	Optimal width of a single row	< 2000
10	Optimal capacity of a single column	< 10 MB
11	Optimal SQL statement length	< 5000
12	Percentage of available disk space	85% (If the disk capacity is greater than 24 TB, 90% is recommended.)