Functions for Deleting Residual Files

The pgxc residual file management function only operates on the CN and the current primary DN, and does not verify or clear residual files on the standby DN. Therefore, after the primary DN is cleared, you need to clear residual files on the standby DN or build the standby DN in a timely manner. This prevents residual files on the standby DN from being copied back to the primary DN due to incremental build after a primary/standby switchover.

pg_rm_residualfiles(filepath)

Description: Deletes files from a specified residual file list on the current instance. This function is an instance-level function and is irrelevant to the current database. It can run on any instance.

Parameter type: text

Return type: record

The following table describes return columns.

**Table 1** pg_rm_residualfiles (filepath) return fields
Column	Type	Description
result	bool	Deletion completed or not

Example:

    
         SELECT * FROM pg_rm_residualfiles('pgrf_20200908160211441599');
 result 
--------
 t
(1 row)

Residual files can be deleted only after verification using the pg_verify_residualfiles() function.
All verified files, regardless which database they are in, will be deleted.
If all files recorded in the specified file have been deleted, the specified file will be removed and backed up in the $PGDATA/pg_residualfile/backup directory.

pg_rm_residualfiles()

Description: Deletes all files recorded on all residual file lists on the current instance. This function is an instance-level function and is irrelevant to the current database. It can run on any instance.

Parameter type: none

Return type: record

The following table describes return columns.

**Table 2** pg_rm_residualfiles () return fields
Column	Type	Description
result	bool	Deletion completed or not
filepath	text	Residual file path
notes	text	Notes

Example:

    
         SELECT * FROM pg_rm_residualfiles();
 result |         filepath          | notes 
--------+---------------------------+-------
 t      | pgrf_20200908160211441546 | 
(1 row)

Residual files can be deleted only after verification using the pg_verify_residualfiles() function.
All verified files, regardless which database they are in, will be deleted.
If all files recorded in the specified file have been deleted, the specified file will be removed and backed up in the $PGDATA/pg_residualfile/backup directory.

pgxc_rm_residualfiles()

Description: Unified CN query function of pgxc_rm_residualfiles. This function is a cluster-level function and is irrelevant to the current database. It runs on CNs.

Parameter type: none

Return type: record

The following table describes return columns.

**Table 3** pgxc_rm_residualfiles () return fields
Column	Type	Description
nodename	text	Node name
result	bool	Deletion completed or not
filepath	text	Residual file path
notes	text	Notes

Example:

    
         SELECT * FROM pgxc_rm_residualfiles();
   nodename   | result |         filepath          | notes 
--------------+--------+---------------------------+-------
 cn_5001      | t      | pgrf_20200910170129360401 | 
 dn_6001_6002 | t      | pgrf_20200908160211441546 | 
(2 rows)