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how_to:repairing_corrupted_database [2016/04/06 11:15] – paulhow_to:repairing_corrupted_database [2024/01/15 11:35] (current) – paul
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 If that is not possible, then in some cases, you may be able to remove the damaged parts of the database and recover from there while keeping most of the important data intact. This article explains some possible ways to do this. Note that none of these methods are guaranteed, and are done at your own risk. If that is not possible, then in some cases, you may be able to remove the damaged parts of the database and recover from there while keeping most of the important data intact. This article explains some possible ways to do this. Note that none of these methods are guaranteed, and are done at your own risk.
  
-We can help you with these under our chargeable service which costs £30/hr (or part of) for this type of problem, but there are no guarantees we will be able to recover anything.+We can help you with these under our chargeable service which costs £40/hr (or part of) for this type of problem, but there are no guarantees we will be able to recover anything.
  
 Before you start you should: Before you start you should:
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 Then type (or copy/paste) Then type (or copy/paste)
  
-  select n.nspname AS schema, c.relname AS tablename, c.reltype as type from pg_class c inner join pg_namespace n on (c.relnamespace=n.oid) where c.relfilenode=<filename>;+  select n.nspname AS schema, c.relname AS tablename, c.relkind as kind from pg_class c inner join pg_namespace n on (c.relnamespace=n.oid) where c.relfilenode=<filename>;
      
 In the above example error message <filename> would be replaced by 512312 In the above example error message <filename> would be replaced by 512312
  
-If 'type' is 'i' then the damaged relation is an index, so a database reindex should fix the problem. If it is 'r' then it is a normal table, or if it is 't' then it is a 'toast' table (see below).+If 'kind' is 'i' then the damaged relation is an index, so a database reindex should fix the problem. If it is 'r' then it is a normal table, or if it is 't' then it is a 'toast' table (see below). 
 + 
 +If the problem is in a normal table, then depending on the table name, you may be able to delete the table without losing critical data. Please contact support@pscs.co.uk with the table name and we will be able to tell you what is stored in that table, and how to delete it if that is an appropriate action.
  
 =====unexpected chunk number===== =====unexpected chunk number=====
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 Unfortunately, there is no easy way to find which record is damaged, so you need to scan the entire table.  Unfortunately, there is no easy way to find which record is damaged, so you need to scan the entire table. 
  
-Go to a command prompt in the VPOP3 directory and run 'psql' (in version 5 only). The default password is 'vpop3pass'+Go to a command prompt in the VPOP3\pgsql\bin directory and run 'psql -U postgres -p 5433 vpop3' (in version 3 or 4 omit the '-p 5433'). The default password is 'pgsqlpass'
  
 ====Finding the problem message==== ====Finding the problem message====
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     badid INT;     badid INT;
 begin begin
 +DROP TABLE IF EXISTS badids;
 +CREATE TEMP TABLE badids (msgdataid BIGINT);
 FOR badid IN SELECT msgdataid FROM messages.msgdata ORDER BY msgdataid LOOP FOR badid IN SELECT msgdataid FROM messages.msgdata ORDER BY msgdataid LOOP
     curid = curid + 1;     curid = curid + 1;
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     exception     exception
         when others then         when others then
 +            INSERT INTO badids (msgdataid) VALUES(badid);
             raise notice 'data for message % is corrupt', badid;             raise notice 'data for message % is corrupt', badid;
             continue;             continue;
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 This will read all the messages from the database, and tell you which message(s) it encountered an error with This will read all the messages from the database, and tell you which message(s) it encountered an error with
 +
 +However, sometimes it won't find all problem messages, so it is a good idea to run it again after fixing any problems, until this script doesn't find any more errors. 
 +
 +This script stores the bad message IDs in a temporary table called 'badids', so you can look at the values using 'SELECT * FROM badids;' or use the table to help with other functions if it helps (and you know SQL)
  
 ===Getting message summary info=== ===Getting message summary info===
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   SELECT subject, messagetime, fromaddr, tolist FROM messages.msgdata WHERE msgdataid = <problem message id>;   SELECT subject, messagetime, fromaddr, tolist FROM messages.msgdata WHERE msgdataid = <problem message id>;
 and and
-  SELECT username, folder FROM messages.foldermessages INNER JOIN users.users ON messages.foldermessages.userid=users.users.username WHERE msgdataid= <problem message id>;+  SELECT username, folder FROM messages.foldermessages INNER JOIN messages.folders USING(folderid) INNER JOIN users.users ON messages.folders.userid=users.users.usernumber WHERE msgdataid = <problem message id>;
  
 this will tell you summary information about the message which may help know which message will been deleted this will tell you summary information about the message which may help know which message will been deleted
how_to/repairing_corrupted_database.1459941326.txt.gz · Last modified: 2018/11/14 10:44 (external edit)

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