Risky Operations

Perform operations strictly following instructions provided in the guide. Do not perform the following risky operations.

Table 1 describes forbidden operations during routine O&M.

Table 1 Forbidden operations

Forbidden Operation	Risk
Modify the file name, permission, or content, or delete any content in the data directory.	Serious errors occur on DNs and cannot be fixed.
Delete database system catalogs or their data.	Service operations cannot be properly performed.

Table 2 describes risky operations during routine O&M.

Table 2 Risky operations

Category	Risky Operation	Risk	Risk Level	Preventive Measure	Check Item
Database	Open a configuration file and manually modify the port number.	The database fails to be started or connected.	▲▲▲▲▲	Use the required tool to modify the port number.	None
	Incautiously modify the content of the pg_hba.conf file.	The client fails to be connected.	▲▲▲▲▲	Strictly follow the instructions provided in product documentation while you modify this file.	None
	Manually modify the pg_xlog file.	Database startup fails and data becomes inconsistent.	▲▲▲▲▲	Use the required tool to modify this file.	None
Job	Run the kill -9 command to terminate a job process.	System resources occupied by this job cannot be released.	▲▲▲	Log in to the database and use the pg_terminate_backend or pg_cancel_backend function to terminate the job, or press Ctrl+C to terminate the job process.	Resource usage