Skip to main content

Interactive PostgreSQL Script

Do you want an input from end user, while running PostgreSQL script.

No Problem, here is the one of the solution for you.

In the following example, i am taking the confirmation from an end user, before dropping an existing database called "sample".

-- When any exception raised from this script, the complete script execution is going to fail.

-- We will be raising a custom exception, when the Drop DB != 'y|Y';

-- Take input from the user.
\prompt 'Are you sure to drop ' Do_You_Want_To_Drop_Db

-- Get the user input.
\set Do_Drop_Db '\'' :Do_You_Want_To_Drop_Db '\''

-- Creating a temp table to store the value of the user confirmation.
-- This will be dropped when the session got closed.
CREATE TEMP TABLE Drop_Db AS SELECT :Do_Drop_Db::text AS confirm;

RAISE EXCEPTION 'Database won''t drop. Hence closing this session';
RAISE NOTICE 'Database will be droped. Please make sure the connection of this databases get closed.';


Testing the Script
bash-4.1$ ../bin/psql -U postgres -f /tmp/Interactive_Sql.Sql postgres
Are you sure to drop N
psql:/tmp/Interactive_Sql.Sql:28: ERROR:  Database won't drop. Hence closing this session
bash-4.1$ ../bin/psql -U postgres -f /tmp/Interactive_Sql.Sql postgres
Are you sure to drop Y
psql:/tmp/Interactive_Sql.Sql:28: NOTICE:  Database will be droped. Please make sure the connection of this databases get closed.

దినేష్ కుమార్ 
Dinesh Kumar


  1. Thank u for the useful script and I was searching for this style of script in postgres.

  2. You don't know how long have I been looking for a way to get interactive input. Thank you!


Post a Comment

Popular posts from this blog

Pgpool Configuration & Failback

I would like to share the pgpool configuration, and it's failback mechanism in this post.

Hope it will be helpful to you in creating pgpool and it's failback setup.

Pgpool Installation & Configuration

1. Download the pgpool from below link(Latest version is 3.2.1).

2. Untart the pgpool-II-3.2.1.tar.gz and goto pgpool-II-3.2.1 directory.

3. Install the pgpool by executing the below commands:

./configure ­­prefix=/opt/PostgreSQL92/ ­­--with­-pgsql­-includedir=/opt/PostgreSQL92/include/ --with­-pgsql­-libdir=/opt/PostgreSQL92/lib/ make make install 4. You can see the pgpool files in /opt/PostgreSQL92/bin location.
/opt/PostgreSQL92/bin $ ls clusterdb   droplang  pcp_attach_node  pcp_proc_count pcp_systemdb_info  pg_controldata  pgpool pg_test_fsync pltcl_loadmod  reindexdb createdb    dropuser  pcp_detach_node  pcp_proc_info createlang  ecpg      pcp_node_count   pcp_promote_node oid2name  pcp_pool_status  pcp_stop_pgpool  …

pgBucket - A new concurrent job scheduler

Hi All,

I'm so excited to announce about my first contribution tool for postgresql. I have been working with PostgreSQL from 2011 and I'm really impressed with such a nice database.

I started few projects in last 2 years like pgHawk[A beautiful report generator for Openwatch] , pgOwlt [CUI monitoring. It is still under development, incase you are interested to see what it is, attaching the image here for you ],

pgBucket [Which I'm gonna talk about] and learned a lot and lot about PostgreSQL/Linux internals.

Using pgBucket we can schedule jobs easily and we can also maintain them using it's CLI options. We can update/insert/delete jobs at online. And here is its architecture which gives you a basic idea about how it works.

Yeah, I know there are other good job schedulers available for PostgreSQL. I haven't tested them and not comparing them with this, as I implemented it in my way.
Features are: OS/DB jobsCron style sytaxOnline job modificationsRequired cli options

N-Node Mutlimaster Replication With Bucardo...!

Our team recently got  a problem, which is to solve the N-Node multi master replication in PostgreSQL.

We all know that, there are some other db engines like Postgres-XC which works in this way. But, we don't have any tool available in PostgreSQL, except Bucardo.

Bucardo is the nice solution for 2-Nodes. Is there a way we can exceed this limitation from 2 to N..?

As an initial step on this, I have done with 3 Nodes, which I believe, we can extend this upto N. { I might be wrong here.}

Please follow the below steps to set up the 1 - 1 multi master replication.

1. Follow the below steps to get all the pre-requisites for the Bucardo.

yum install perl-DBIx-Safe or apt-get install libdbix-safe-perl Install the below components from CPAN. DBI DBD::Pg Test::Simple boolean (Bucardo 5.0 and higher) Download the latest tarball from here. tar xvfz Bucardo-4.4.8.tar.gz cd Bucardo-4.4.8 perl Makefile.PL make sudo make install 2. We need to create plperl extension in db. For this, download…