docs: add 10-pg_clean.en.md English translation

docs/guide/10-pg_clean.en.md

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+# V2.3.0 Upgrade Features: pg_clean Usage Instructions
+
+## 1. Install the pg_clean Tool:
+Connect to any primary CN:
+
+```
+CREATE EXTENSION pg_clean;
+```
+
+## 2. Construct a Two-Phase Transaction Residual Scenario:
+session1—cn1
+
+```
+begin;
+create table a (id int);
+prepare transaction 'create_a';
+set xc_maintenance_mode = on;
+execute direct on (dn002) 'rollback prepared ''create_a''';
+set xc_maintenance_mode = off;
+\q
+```
+
+In this scenario we create a two-phase transaction whose gid is 'create\_a', and then turn on xc\_maintenance\_mode so that the transaction is rolled back only on dn002.
+
+## 3. Find Residual Two-Phase Transactions in the Cluster:
+session2—cn2
+
+```
+select * from pg_clean_check_txn();
+```
+![pg_clean_check_txn](images/v.2.3.0_pg_clean_check_txn.png)
+
+The figure above prints out the residual two-phase transactions in the cluster. `gid` is the global identifier of the transaction, global\_transaction\_status is the global status of the transaction, and transaction\_status\_on\_allnodes is the status of the transaction on all nodes.
+
+## 4. View the Names of the 2PC Residual Files
+
+Query the names of all 2PC residual files under the `pg_2pc` data directory on node cn1
+
+session1—cn1
+
+```
+postgres=# select * from pgxc_get_record_list();
+ pgxc_get_record_list 
+----------------------
+ create_a
+(1 row)
+```
+
+## 5. Clean Up Residual Two-Phase Transactions in the Cluster:
+session2—cn2
+
+```
+select * from pg_clean_execute();
+```
+![pg_clean_execute](images/v2.3.0_pg_clean_execute.png)
+
+The figure above prints out all residual two-phase transactions, as well as the operations performed on them. `operation` is the operation performed on the transaction on each node, and operation\_status indicates whether that operation was executed successfully. Because the global transaction status of this transaction is ABORT, we go to every node whose status is prepare and perform a rollback on the transaction there.
+
+## 6. Check Whether the Cleaned Two-Phase Transactions Still Have Residual File Records:
+session1—cn1
+
+```
+postgres=# select * from pgxc_get_record_list();
+ pgxc_get_record_list 
+----------------------
+
+(1 row)
+```
+
+Because pg\_clean\_execute was executed successfully in the previous step, the file records of the already rolled back transaction 'create_a' have been deleted on all nodes. Here we check all 2pc file records on cn1, and they are displayed as empty — the result is correct.