I accidentally dropped a database which I used for my web application, and it is in MySQL. Browsing through the internet I found out that to recover you need to have binary logs enabled. Read that binary logs records only changes in tables, so what it has to do with recovering a db. Upon executing the command "show binary logs;" console shows me "Error Code: 1381. You are not using binary logging". I am a newbie to MySQL, so is it possible to recover it without my binary logging enabled PLUS I have not made any real backup for the db. Going through the MySQL "my.cnf" file found that InnoDB is default enabled, can it help me recover.
If I cannot recover, please mention the steps to be carried out next time creating a new db to ensure that I could recover even if it has been accidentally deleted.
I think it can't be recovered. In case of this case, you can do the following when creating a new db:
open the binary log by add the following:
log-bin=/data/mysqlbinlog/mysql-bin
binlog-format=mixed (or row)
create a slave db.
Good luck for you.
Related
I accidentally deleted records in MSQL database and there is no backup no rollback transaction and i reallly want to recover deleted data back is there any tool to help ? how could i do ? please help me .
Is it MySQL or MSSQL they both are not same. MSSQL stands for SQL Server but by any means for you to recover deleted data either you should have taken a recent full/differential backup in place (or) if you have maintained transaction log. Then yes possible to get back your data by restoring from your backup (or) by reading from transaction log. Else, No there is no way to recover those data.
For InnoDB tables, if binary logs are enabled, one could use:
mysqlbinlog path_to_binary_log_file > query_log.sql
If binary logs are not enabled, there is a recovery tool provided by Percona which may help.
Created a script to automate the steps from the Percona tool which recovers the deleted rows (if exist) and provides SQL queries to load the data back into database.
Please note:
The time between the deletion of rows and the database stop is
crucial. If pages are reused you can’t recover the data.
Today morning I surprisingly found that some data is deleted form my MYSQL database, I am unable to find that data in any table.
Please suggest how to recover data from MySQL database, DOES MYSQL keeps any Log if yes where it is located?
Please suggest any query to get all records.
I am using MYSQL Workbench 5.
If you have binary logs active on your server then you can use mysqlbinlog
You can use the following:
mysqlbinlog binary_log_file > query_log.sql
If you don't have this, then you have probably lost it.
You can look here for more information on how to convert the binary logs to sql.
You can check if binary logging is enabled or not by running the following command:
SHOW VARIABLES LIKE 'log_bin';
For InnoDB tables, if binary logs are not enabled, there is a recovery tool provided by Percona which may help.
Created a script to automate the steps from the Percona tool which recovers the deleted rows (if exist) and provides SQL queries to load the data into database.
Please note:
The time between the deletion of rows and the database stop is
crucial. If pages are reused you can’t recover the data.
I understand I need to fully backup the log file before I do anything.
But, once I do that, what would happen if I followed the procedure for detaching the database and then deleting the log file and then recreating it?
This could be quick way of shrinking database log file because sp_attach_db will automatically create a new log file of the original size specified with the database creation.
And also detach procedure is safe as SQL Server ensure that server is cleanly detaching database files which means
1. No incomplete transactions are in the database
2. Memory has no dirty pages for DB
After I ran the transaction log backup twice and ran the shrink command all is good in the world.
Thanks
Once you delete and recreate the log file, it will create the t-log from no knowledge of the DB state and you may encounter data lost.
I am looking to write a backup / restore script based on MYSQL's binary logging.
I have a database on a mysql server, and my colleague also has his own database on the same mysql server.
Looking at the binary logs, I see the statements are logged for both these databases.
Is the database being written to specified in the logs?
Can I safely replay a binary log containing an extra database in it - i.e. I want to replicate database_A, my binary log file contains commands sent to database_A as well as database_B, can I replay these commands into a copy of database_A safely? Or do I need to ask my sysadmin to only log things for dataabse_A?
OK, studying the log files a bit more, it seems that the mysql binlog utility adds the "use database" statements in the appropriate place. I added a part to my script that effectively grepped out the relevant database statements.
all,
I use mysqldump to backup mysql cluster data with 10 million lines data daily. Recently, our cluster is crashed after a update, then we restore the .sql file generated by mysqldump. When restoring the database, we got key duplication errors/problem, and then I use "-f" to force the restore process. And finally, the restore process completed and all tables is back. Some tables are smaller, we think that is because the duplicate lines are ignored.
But recently, we find some data is missing, it seems that some duplicated data dose not restored correctly.
May I know whether there is a nice way to avoid this in restore process or how to check whether we have duplication before mysqldump?
Couple of suggestions - take a look at the errors that are generated when not using the force option and see if you can figure out how to fix the root cause. Using the force option allows the restore to continue after the error but the failed rows will still be lost.
Is there a reason why you're using mysqldump rather than the backup command within ndb_mgm - which is an online operation? If using the native Cluster (on-line!) backup then you use the ndb_restore command to restore your data.