Setting Parameters
Context
GaussDB provides multiple methods to set GUC parameters for databases, users, or sessions.
- Parameter names are case-insensitive.
- The parameter values can be integers, floating points, strings, Boolean values, or enumerated values.
- The Boolean values can be on/off, true/false, yes/no, or 1/0, and are case-insensitive.
- The enumerated value range is specified in the enumvals column of the system catalog pg_settings.
- For parameters using units, specify their units during the setting. Otherwise, default units are used.
- The default units are specified in the unit column of pg_settings.
- The unit of memory can be KB, MB, or GB.
- The unit of time can be ms, s, min, h, or d.
For details about parameters, see GUC Parameters.
Setting GUC Parameters
GaussDB provides seven types of GUC parameters. For details about parameter types and their setting methods, see Table 1.
Parameter Type |
Description |
Setting Method |
---|---|---|
INTERNAL |
Fixed parameters. They are set during database creation and cannot be modified. Users can only view the parameters by running the SHOW command or in the pg_settings view. |
None. |
POSTMASTER |
Database server parameters. They can be set when the database is started or in the configuration file. |
Method 1 in Table 2. |
SIGHUP |
Global database parameters. They can be set when the database is started or be modified later. |
Method 1 or 2 in Table 2. |
BACKEND |
Session connection parameters. They are specified during session connection creation and cannot be modified after that. The parameter setting becomes invalid when the session is disconnected. The parameters of this type are internal parameters and not recommended for users to set it. |
Method 1 or 2 in Table 2.
NOTE:
The parameter setting takes effect when the next session is created. |
SUSET |
Database administrator parameters. They can be set by common users during database startup or after the database is started. They can also be set by database administrators using SQL statements. |
Method 1 or 2 by a common user, or method 3 by a database administrator in Table 2. |
USERSET |
Common user parameters. They can be set by any user at any time. |
Method 1, 2, or 3 in Table 2. |
No. |
Setting Method |
||||||
---|---|---|---|---|---|---|---|
Method 1 |
|
||||||
Method 2 |
|
||||||
Method 3 |
Set parameters at the database, user, or session level.
|

- If you use method 1 or method 2 to set a parameter that does not belong to the current node, the database displays a message indicating that the parameter is not supported.
- You cannot set a parameter in the unit of pages by using method 1 or method 2.
- When you use method 3 to set a parameter, if the parameter value is an integer, leading zeros will be filtered out. For example, SET paraname TO 008192 and SET paraname TO 8192 have the same effect.
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot