How to backup and restore PostgreSQL programmatically without using pg_dump and psql? - postgresql

I have a kubernetes space where the PostgreSQL DB is on a different POD than the executor where my Typescrtipt code is being executed, which means that I do not have access to pg_dump and psql. Is there a typescript npm library which can backup and restore the DB programmatically and remotely or a special client which I can install in project so that I can use? I could not find such an mpm library or client on the internet.
Another thing that I can think of is some "universal" SQL script, which makes the backup and another one for the restore, if there is such a thing at all.

Related

PGAdmin restore remote database [duplicate]

This question already has answers here:
Export and import table dump (.sql) using pgAdmin
(6 answers)
Closed 1 year ago.
Let I first state that I am not a DBA-guy but I do have a question regarding restoring remote databases using PG Admin.
I have this PG Admin tool (v4.27) running in a Docker container and I use this portal to maintain two separate Postgress databases, both running in a Docker container as well. I installed PG Agent in both database containers and run scheduled daily backup's, defined via PG Admin and stored in the container of each corresponding databases. So far so good.
Now I want to restore one of these databases by using the latest daily backup file (*.sql), but the Restore Dialog of PG Admin only looks for files stored locally (the PG Admin container)?
Whatever I tried or searched for on the internet, to me it seems not possible to show a list of remote backup files in PG Admin or run manually a remote SQL file. Is this even possible in PG Admin? Running psql in the query editor is not possible (duh ...) and due to not finding the remote SQL-restore file I have no clue how to run this code within PG Admin on the remote corresponding database container.
The one and only solution so far I can think of, is scheduling a restore which has no calendar and should be triggered manually when needed, but it's not the prettiest solution.
Do I miss something or did I overlook the right documentation or have I created a silly, unmaintainable solution?
Thanks in advance for thinking along and kind regards,
Aad Dijksman
You cannot restore a plain format dump (an SQL script) with pgAdmin. You will have to use psql, the command line client.
COPY statements and data are mixed in such a dump, and that would make pgAdmin choke.
The solution by #Laurenz Albe points out that it is best to use the command line psql here, and that would be my first go-to.
However, if for whatever reason you don't have access to the command line and are only able to connect to this database via pgadmin, there is another solution which you can find here:
Export and import table dump (.sql) using pgAdmin
I recommend looking at the solution by Tomas Greif.

How to use PoWA at a backup database?

I'm giving a try on PoWA, but I've got a little problem.
My Postgres database is running on AWS RDS.
PoWA needs HypoPG in order to suggest indexes.
But RDS doesn't support HypoPG extension. So I had to install PoWA at my backup database (outside RDS).
The problem is: PoWA isn't analyzing the restored database. It can't recognizes any data. If I execute some SQL queries manually it works though.
Is there something that I can be missing?
And, when I tried Ankane Dexter, I could show it the log files path (dumped at the backup database in parallel). Is there a way to do so in PoWA?
Thanks.

How to load data from S3 to PostgreSQL RDS

I have a need to load data from S3 to Postgres RDS (around 50-100 GB) I don't have the option to use AWS Data Pipeline and I am looking for something similar to using the COPY command to load data in S3 into Amazon Redshift.
I would appreciate any suggestions on how I can accomplish this.
Originally, this answer was trying to use the S3 to Postgres RDS Functionality. That whole enterprise failed (see below).
The way I have finally been able to do this is:
Set-up an EC2 instance with psql installed (see below near end of post)
Copy the relevant CSVs to import from S3 to the local instance
Use the psql /copy command to import the files up
This last part is really, really important. If you use the SQL COPY command the entire RDS Postgres role structure will frustrate you to no end. It has a wonky SUPERRDSADMIN role which is not very super at all. However, if you use the psql /copy commany you apparently can do anything. I have confirmed this be the case and have started my uploads succesfully. I will come back and re-edit this post (time permitting) to add relevant documentation steps for the above.
Caveat Emptor: The post below was all the original work I had done trying to get this implemented. I don't want to bury the lead despite multiple efforts (including what can only be described as pathetic tech support from AWS) I don't believe that this feature is ready for prime time. Despite a very simple test environment, easy to replicate, AWS has not provided an effective way to not get the copy statement to crap out as follows:
The actual call to aws_s3.table_import_from_s3(...) is reporting a permission problem between RDS and S3. From my research work with psql this appears to be a C library, probably installed by AWS.
NOTICE: CURL error code: 28 when attempting to validate pre-signed URL, 1 attempt(s) remaining
NOTICE: HINT: make sure your instance is able to connect with S3.
S3 to Postgres RDS Functionality Now Added
On 2019-04-24 AWS released functionality allowing a Postgres RDS to load directly from S3. You can read the announcement here, and see the documentation page here.
I am sharing with the OP because this appears to be the AWS supported way of solving the question posed.
Key summary points:
Requires Postgres 11.1 or greater
Need access to psql and the ability to connect it to the RDS instance
Need to install the aws_s3 extension which pulls in aws_commons.
You can get to the S3 bucket by specifying credentials or by assigning IAM roles to RDS
It advertises supporting all of the same data formats as the postgres COPY command
It currently only appears to support a single file at a time (ie no regex)
The instructions are fairly detailed and provide a variety of paths to configuring (AWS CLI scripts, Console instructions, etc). Additionally, the option to use your IAM keys rather than have to set-up roles is nice.
I did not find a way to download just psql, so I had to bring down a full postgres install down to my mac, but that was no big deal with brew:
brew install postgres
and since the DB service does not get activated it is the quickest way to get psql.
Update: Decided that having psql on my mac was a security hole, port forwarding, etc. I found that there is a simple Postgres install available for AMI Linux 2 under the AMI Extras rubric. The install command is fairly simple on your ami instance type.
sudo amazon-linux-extras install postgresql10
psql is fairly easy to use, however, important to keep in mind that any instructions to psql itself are escaped by a \. Documentation on psql can be found here. Recommend going through it at least once before executing the AWS recommended scripts.
To the extent you run tight security and have access to your RDS instances seriously restricted (which I do) don't forget to open up the ports from your AMI instance running Postgres to your RDS instance.
If your preference is a GUI then you can try to use PGAdmin4. It is the AWS recommended way of connecting to RDS Postgres instances according to the docs. I was unable to get any of the SSH tunneling features to work (which is why I ended up doing the localhost SSH mapping that I used for psql). I also found it to be rather buggy in other ways. Reading reviews of the product it seems that version 4 may not be the stablest of releases.
http://docs.aws.amazon.com/redshift/latest/dg/t_loading-tables-from-s3.html
Use the COPY command to load a table in parallel from data files on
Amazon S3. You can specify the files to be loaded by using an Amazon
S3 object prefix or by using a manifest file.
The syntax to specify the files to be loaded by using a prefix is as
follows:
copy <table_name> from 's3://<bucket_name>/<object_prefix>'
authorization;
update
Another option is to mount s3 and use direct path to the csv with COPY command. I'm not sure If it will hold 100GB effectively, but worth of trying. Here is some list of options on software.
Yet another option would be "parsing" s3 file part by part with something described here to a file and COPY from named pipe, described here
And the most obvious option to just download file to local storage and use COPY I don't cover at all
Also worth of mentioning would be s3_fdw (status unstable). Readme is very laconic, but I assume you could create a foreign table leading to s3 file. Which itself means you can load data to other relation...

Remote trigger a postgres database backup

I would like to backup my production database before and after running a database migration from my deploy server (not the database server) I've got a Postgresql 8.4 server sitting on a CentOS 5 machine. The website accessing the database is on a Windows 2008 server running an MVC.Net application, it checks out changes in the source code, compiles the project, runs any DB Changes, then deploys to IIS.
I have the DB server set up to do a crontab job backup for daily backups, but I also want a way of calling a backup from the deploy server during the deploy process. From what I can figure out, there isn't a way to tell the database from a client connection to back itself up. If I call pg_dump from the web server as part of the deploy script it will create the backup on the web server (not desirable). I've looked at the COPY command, and it probably won't give me what I want. MS SQLServer lets you call the BACKUP command from within a DB Connection which will put the backups on the database machine.
I found this post about MySQL, and that it's not a supported feature in MySQL. Is Postgres the same? Remote backup of MySQL database
What would be the best way to accomplish this? I thought about creating a small application that makes an SSH connection to the DB Server, then calls pg_dump? This would mean I'm storing SSH connection information on the server, which I'd really rather not do if possible.
Create a database user pgbackup and assign him read-only privileges to all your database tables.
Setup a new OS user pgbackup on CentOS server with a /bin/bash shell.
Login as pgbackup and create a pair of ssh authentication keys without passphrase, and allow this user to login using generated private key:
su - pgbackup
ssh-keygen -q -t rsa -f ~/.ssh/id_rsa -N ""
cp -a ~/.ssh/.id_rsa.pub ~/.ssh/authorized_keys
Create a file ~pgbackup/.bash_profile:
exec pg_dump databasename --file=`date +databasename-%F-%H-%M-%S-%N.sql`
Setup your script on Windows to connect using ssh and authorize using primary key. It will not be able to do anything besides creating a database backup, so it would be reasonably safe.
I think this could be possible if you create a trigger that uses the PostgreSQL module dblink to make a remote database connection from within PL/pgSQL.
I'm not sure what you mean but I think you can just use pg_dump from your Windows computer:
pg_dump --host=centos-server-name > backup.sql
You'd need to install Windows version of PostgreSQL there, so pg_dump.exe would be installed, but you don't need to start PostgreSQL service or even create a tablespace there.
Hi Mike you are correct,
Using the pg_dump we can save the backup only on the local system. In our case we have created a script on the db server for taking the base backup. We have created a expect script on another server which run the script on database server.
All our servers are linux servers , we have done this using the shell script.

Postgresql cluster initialization

SQL distributes pre-initialized catalog cluster but for postgresql we need initialize cluster using initdb and a network service account. It fails in few cases and causing bit of misery!
Can initialize cluster ourselves and distribute pre-initialized cluster?
Thanks
The "cluster" (or data directory) depends on the operating system and the architecture. So a data directory that was initialized with initdb on a 32bit Linux will not work on a 64bit Windows.
But you don't need to do that. A service account is only necessary if you want to run PostgreSQL as a service.
You can easily use the ZIP distribution to install and start Postgres without the need for a full-fledge installation or a service account.
The steps to do so are:
Unzip the binaries
Run initdb pointing it to the directory where the database cluster should be created.
Run pg_ctl to start the server.
Note that the steps 2) and 3) must be run using the same user, otherwise the server will have no priviliges to write to the data directory.
These steps can easily be put into a batch file or shell script.
Hard to understand your question, but I think you are talking about the Windows installer for PostgreSQL. Right? What version, what installer, what about error messages, loggings, etc. ?
The installer can be found here.
SQL = database language, SQL Server =
Microsoft database product