Repairing a Ledger Database

Prerequisites

• You are an audit administrator or a role that has the audit administrator permissions.
• The database is running properly, and a series of addition, deletion, and modification operations are performed on the tamper-proof database to ensure that operation records are generated in the ledger for query.

Context

• When an exception occurs or a global blockchain table or user history table is damaged, you can use the ledger_gchain_repair(tex… or ledger_hist_repair(text,… interface to repair the table. After the fault is rectified, the result of invoking the global blockchain table or user history table verification interface is true.

• The interface for repairing a user history table is pg_catalog.ledger_hist_repair. To repair the table, run the following command:

  SELECT pg_catalog.ledger_hist_repair(schema_name text,table_name text);
  

  If the repair is successful, the function returns the hash increment of the user history table during the repair.

• The interface for repairing the global blockchain table is pg_catalog.ledger_gchain_repair. To repair the table, run the following command:

  SELECT pg_catalog.ledger_gchain_repair(schema_name text,table_name text);
  

  If the repair is successful, the function returns the hash increment of the global blockchain table during the repair.

Procedure

1. Repair a specified user history table.

   openGauss=# SELECT pg_catalog.ledger_hist_repair('ledgernsp', 'usertable');
   

   The query result is as follows:

    ledger_hist_repair
   --------------------
    84e8bfc3b974e9cf
   (1 row)
   

   The query result indicates that the user history table on the current node is successfully repaired. The hash increment of the user history table is 84e8bfc3b974e9cf.

2. Repair a specified global blockchain table.

   openGauss=# SELECT pg_catalog.ledger_gchain_repair('ledgernsp', 'usertable');
   

   The query result is as follows:

    ledger_gchain_repair
   ----------------------
    a41714001181a294
   (1 row)
   

   The query result indicates that the global blockchain table is successfully repaired and a piece of repair data is inserted. The hash value is a41714001181a294.