I accidentally dropped original postgres database after installing postgreSQL software. Postgres user is still there, \du superuser. How to recover or recreate original postgres database?
https://www.postgresql.org/docs/current/static/sql-createdatabase.html
just run
create database postgres;
it will create db with default template (which is "template1"). If you did not modify it - it will be same is previous "postgres" db
You can only recover it if you have some previous backup of that database, by restoring that backup and then applying WAL files upto the time when drop database statement was issued.
There is no other way to recover a dropped database.
Related
I accidentally restored another database as the default postgres database, how do I correct this?
postgres v10 on ubuntu.
To be specific. Log into a database other then postgres.
Then:
DROP DATABASE postgres;
CREATE DATABASE postgres; --You don't need to specify template1 it is the default.
Then do your restore. If you are using pg_restore make sure you use -C to have the database CREATEd properly.
I have accidentally deleted the default "postgres" database from my postgres. I've read that:
Most Postgres servers have three databases defined by default: template0 , template1 and postgres . template0 and template1 are skeleton databases that are or can be used by the CREATE DATABASE command. postgres is the default database you will connect to before you have created any other databases.
I have now created again a postgres database by running CREATE DATABASE postgres.
Do I need to do anything else to basically redo deleting the "postgres" database? Or the current one is basically the same?
Thanks
The database postgres is in no way special. You should use the bootstrap superuser (normally postgres) as the database owner, then the database will be just as good as the original postgres database.
The only difference is that the new database will have an OID ≥ 16384, which identifies it as an object created after cluster initialization. However, a quick look through the source code makes me believe that we don't use that anywhere.
I have server1 and server2 in my environment, both have db2 v11.1 installed.
I have already done an online tablespaces (TS1, TS2, TS3) incremental backup of my database GS_DB and obtained the below 3 images.
Image1 at timestamp1: 20190215162151 (full online backup of TS1,TS2,TS3)
Image2 at timestamp2: 20190215162254 (incremental online backup of TS1,TS2,TS3)
Image3 at timestamp3: 20190215162725 (incremental online backup of TS1,TS2,TS3)
In server1, suppose I want to restore my db to image2 (20190215162254), I can do:
db2ckrst -d GS_DB -t 20190215162254 -r tablespace
Suggested restore order of images using timestamp 20190215162254 for database gs_db.
====================================================================
restore db gs_db tablespace ( TS1, TS2, TS3 ) incremental taken at 20190215162254
restore db gs_db incremental taken at 20190215162151
restore db gs_db incremental taken at 20190215162254
====================================================================
If I follow the order and restore to the existing GS_DB in server1, it is working fine.
Now I transferred 3 images to server2 and created an empty database GS_DB in server2, then try to use the above command to restore tablespaces TS1,TS2,TS3 to GS_DB in server2:
db2 restore db gs_db2 tablespace ( TS1, TS2, TS3 ) incremental taken at 20190215162254
SQL2560N The table space restore operation failed because the target database is not identical to the source database.
Already stuck at the first command, does it mean we cannot restore tablespace backup image across two different db? Any way I can do it?
Thanks in advance!
Every database has an unique internal identifier called Seed. You can't create another database with the same Seed as the existing one, even you create it with the same name. These databases are different from the DB2's point of view.
Citation from the Restoring to an existing database article:
The database manager assigns the seed when you create the database.
Db2® always uses the seed from the backup image.
You can restore a table space into an existing database only if the table space exists and if the table spaces are the same, meaning that you did not drop
the table space and then re-create it between the backup and the
restore operations.
The database on disk and in the backup image must
be the same.
So, yes, you are not able to restore tablespace backup image across two different db in the way you try.
Read about the Database schema transporting feature.
I have restored a snapshot from an existing RDS PostgreSQL database. Now I want to rename that database but can't find how to do it anywhere in the AWS documentation.
Nor can I find how to use the master password (which I expect let's me do it).
Logging in with postgres into template1 database and then ALTER DATABASE foo RENAME TO bar; worked
I'm having some trouble backing up and restoring a database in pgAdmin.
With pgAdmin, the backup is pretty simple.
If I try to restore the data to my live database, I get all kinds of foreign key errors and duplicate data. So the only way for me now is to drop all constraints, drop all tables and run the restore.
Is there a simpler way to restore a live database? My systems are not directly connected, I'm using file transfer to copy over the backed up db dump.