I am going to make a continuos backup for a PostgreSQL database, incremantal backup, indeed. In this regard, I have a main postgres database (database A) that data are continuously injecting and another database (database B) that it expects to receive the backup data from the main database.
I have already made a "basebackup" for the main database A and the incremental wal files are creating correctly. How can I import these basebackup and wal files in the database B?
Related
It is know fact that backup and restore is a slow in Postgres
I'd like to deploy database to PostgreSQL server as fast as posible (Like it is possible in MS SQL just file copy and attach).
So If I:
backup and restore schema only.
And than copy database oid folder (data files) in to the appropriate oid ?
Will it work?
of not what I also need to be consider.
No, that won't work.
A database backup and restore can never be faster than copying the files is. So stop the database, copy the complete cluster and start PostgreSQL again. It won't get any faster.
I'm working in Teradata Database Express 14.04
I took the particular database build( backup the database) in Teradata Database.
The Archived file is stored in /roor/Documents/TD_BUILD. The file extension of TD_BUILD is (.File).
Now, how to import that file into new Database in Teradata?
To restore to a different system and/or database or to restore a dropped table you need a COPY instead of a RESTORE:
copy data tables(xyz),release lock,file=test;
Caution, restoring on database level drops all objects within first, i.e. ARCMAIN submits a DELETE DATABASE.
If you restore to a different database:
copy data tables(newdb) (from (xyz)),release lock,file=test;
I have got 2 postgresql servers on 2 different computers that are not connected.
Each server holds a database with the same schema.
I would like one of the server to be the master server: this server should store all data that are inserted on both databases.
For that I would like to import regularly (on a daily basis for example) data from one database to the second database.
It implies that I should be able to :
"dump" into file(s) all data that have been stored in the first database since a given date.
import the exported data to the second database
I haven't seen any time/date option in pg_dump/pg_restore commands.
So how could I do that ?
NB: data are inserted in the database and never updated.
I haven't seen any time/date option in pg_dump/pg_restore commands.
There isn't any, and you can't do it that way. You'd have to dump and restore the whole database.
Alternatives are:
Use WAL based replication. Have the master write WAL to an archive location, using an archive_command. When you want to sync, copy all the new WAL from the master to the replica, which must be made as a pg_basebackup of the master and must have a suitable recovery.conf. The replica will replay the master's WAL to get all the master's recent changes.
Use a custom trigger-based system to record all changes to log tables. COPY those log tables to external files, then copy them to the replica. Use a custom script to apply the log table change records to the main tables.
Add a timestamp column to all your tables. Keep a record of when you last synced changes. Do a \COPY (SELECT * FROM sometable WHERE insert_timestamp > 'last_sync_timestamp') TO 'somefile' for each table, probably scripted. Copy the files to the secondary server. There, automate the process of doing a \copy sometable FROM 'somefile' to load the changes from the export files.
In your situation I'd probably do the WAL-based replication. It does mean that the secondary database must be absolutely read-only though.
I'm using pgAdmin to restore PostgreSQL database. To restore the database I need to delete, drop and remake it. How to restore the database without deleting and remaking it?
This cannot be done in pgAdmin or with any database tools. Regular backup files cannot be restored without deleting the data first because they consist of normal COPY statements which will fail if you have rows in the database (primary keys collide etc).
For a simple way to get back to an earlier snapshot in a testing environment take a look at PostgreSQL documentation - 24.2. File System Level Backup:
For backup:
Shut down your database
copy all the files from your data directory
For restore:
Shut down your database
replace your data directory with the backup directory
Note:
the size of the data might be significantly larger than with a regular backup especially if you have a lot of indexes
this is a server wide backup so you can't do this on individual databases
don't attempt to use it on a different version of PostgreSQL
this really deletes the data too - by replacing it with the backup
Also with regular backups you don't have to do a DROP TABLE if you do a data-only restore with pg_restore --data-only for example. You still have to delete the data though.
I have two databases on Amazon RDS, both Postgres. Database 1 and 2
I need to restore an instance from a snapshot of Database 1 for my Staging environment. (Database 2 is my current Staging DB).
However, I want the data from a few of the tables in Database 2 to overwrite the tables in the newly restored snapshot. What is the best way to do this?
When restoring RDS from a Snapshot, a new database instance is created. If you only wish to copy a portion of the snapshot:
Restore the snapshot to a new (temporary) database
Connect to the new database and dump the desired tables using pg_dump
Connect to your staging server and restore the tables using pg_restore (most probably deleting any matching existing tables first)
Delete the temporary database
pg_dump actually outputs SQL commands that are then used to recreate tables and restore data. Look at the content of a dump to understand how the restore process actually works.
I hope this still works for someone else.
With my team we faced a similar issue. We also had 2 Postgres databases and we also just needed to backup some tables from db1 to db2.
What we did is to use a lambda function using Python (from AWS lambda ofc) that connected to both databases and validates if db1.table1 has the same data as db2.table1, if not, then the lambda function should write the missing data from db1.table1 into db2.table1. The approach of using lambda was because we wanted to automate the process due to the main db (let's say db1) is constantly being updated. In addition, it allowed us to only backup our desired tables (let's say 3 tables out of 10), instead of backing up the whole database.
Note: Maybe you want to do these writes using temporary tables to avoid issues with any constraints you have in your tables.