环境介绍：12c->19c
[oracle@enmoedu1 dpdump]$ expdp system/oracle directory=DATA_PUMP_DIR dumpfile=STATE_2018112201_%U.dmp logfile=STATE_112210.log include=db_link full=y
Export: Release 12.2.0.1.0 - Production on Fri Jun 4 15:45:56 2021
Copyright (c) 1982, 2017, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
Starting "SYSTEM"."SYS_EXPORT_FULL_01": system/******** directory=DATA_PUMP_DIR dumpfile=STATE_2018112201_%U.dmp logfile=STATE_112210.log include=db_link full=y
Processing object type DATABASE_EXPORT/SCHEMA/DB_LINK
Master table "SYSTEM"."SYS_EXPORT_FULL_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SYSTEM.SYS_EXPORT_FULL_01 is:
/u01/app/oracle/admin/PROD/dpdump/STATE_2018112201_01.dmp
Job "SYSTEM"."SYS_EXPORT_FULL_01" successfully completed at Fri Jun 4 15:46:01 2021 elapsed 0 00:00:04
[oracle@rac1 dpdump]$ impdp system/oracle directory=DATA_PUMP_DIR dumpfile=STATE_2018112201_%U.dmp logfile=STATE_112210.log
Import: Release 19.0.0.0.0 - Production on Fri Jun 4 15:46:05 2021
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_FULL_01": system/******** directory=DATA_PUMP_DIR dumpfile=STATE_2018112201_%U.dmp logfile=STATE_112210.log
Processing object type DATABASE_EXPORT/SCHEMA/DB_LINK
Job "SYSTEM"."SYS_IMPORT_FULL_01" successfully completed at Fri Jun 4 15:46:10 2021 elapsed 0 00:00:03
SQL> select owner,object_name from dba_objects where object_type='DATABASE LINK';
OWNER
--------------------------------------------------------------------------------
OBJECT_NAME
--------------------------------------------------------------------------------
SYS
SYS_HUB
PUBLIC
TESTLINK1.ENMOEDU.COM