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How to get rid of corruption in PostgreSQL database?
Before doing anything else: Stop the postmaster and take a file system level copy of your database NOW!. Don’t use pg_dump, instead make a copy of all the files in the data directory (the one that contains the “base”, “pg_xlog”, “pg_clog” etc folders).
How to recover Postgres databases from raw physical files?
If you have not got a backup with “pg_dump” and your old data is folder, try the following steps. In the Postgres database, add records to the “pg_database” table. With a manager program or “insert into”. Make the necessary check and change the following insert query and run it. The query will return an OID after it has worked.
Why is Postgres not able to copy files?
When you’re done copying the files and setting permissions, start it again. Second, you need to set the permissions for the data files. Because postgres server actually runs on another user account, it will not be able to access the files if you just copy them into the data folder, because it will not have permissions to do so.
How to save a Postgres database to disk?
Just save the data directory to disk. When launching Postgres, set the parameter telling it where the data directory is (see: wiki.postgresql.org ). Or remove original data directory of the fresh installation and place the copy in its place.
What to do if your data is damaged in PostgreSQL?
Repair efforts usually destroy that evidence. Having the damaged data may be the only way to figure out why it was damaged and how to prevent the same thing happening again. As of PostgreSQL 10, there is am extension called amcheck.
Do you have to run PostgreSQL against a backup?
It should only be run against a copy of the database. Your backup copy is also important evidence that may help figure out what caused the problem, allowing you to prevent it from happening again. Repair efforts usually destroy that evidence.
Is there an AM extension for PostgreSQL 10?
As of PostgreSQL 10, there is am extension called amcheck. Although it only verifies the integrity of B-Tree indexes, it is reasonably well suited for use as a general purpose corruption smoke test, especially because the indexes can be verified against the heap with the “heapallindexed” verification option (later versions only).