How to Drop All Databases Starting With Prefix In Postgresql?

To drop all databases starting with a specific prefix in PostgreSQL, you can write a script that connects to the PostgreSQL server, retrieves a list of databases, filters out those with the specified prefix, and drops them one by one using the DROP DATABASE command. You can achieve this by using a scripting language like Bash, Python, or any other language that can interact with PostgreSQL databases. Simply connect to the database server, retrieve a list of databases using SQL queries, filter out databases with the specified prefix, and execute the DROP DATABASE command for each of them. Make sure to backup any important data before executing the script to avoid data loss. Remember that dropping databases is irreversible and cannot be undone, so proceed with caution.

What is the best practice for dropping databases with a shared prefix in PostgreSQL using a script?

One way to drop databases with a shared prefix in PostgreSQL using a script is to query the pg_database system catalog to get a list of databases with the desired prefix, and then drop each database using a loop. Here is an example script that demonstrates this process:

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#!/bin/bash

PREFIX="mydb_"

# Query the pg_database catalog to get a list of databases with the prefix
DB_LIST=$(psql -U postgres -d postgres -t -c "SELECT datname FROM pg_database WHERE datname LIKE '$PREFIX%';")

# Drop each database with the prefix
for DB_NAME in $DB_LIST; do
  psql -U postgres -d postgres -c "DROP DATABASE $DB_NAME;"
done

In this script:

1. Set the PREFIX variable to the desired prefix shared by the databases you want to drop.
2. Use the psql command to query the pg_database catalog and retrieve a list of database names that have the specified prefix.
3. Iterate over the list of database names and use the psql command to drop each database.

Make sure to replace mydb_ with the actual prefix you want to use in the script. Also, ensure that you have the necessary permissions to drop databases before running this script.

What is the most efficient process for deleting several databases in PostgreSQL at once via psql?

The most efficient process for deleting several databases at once in PostgreSQL via psql is to run a single command that drops all the databases you want to delete. Here is the command you can use:

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DROP DATABASE IF EXISTS database1, database2, database3;

Replace database1, database2, database3 with the names of the databases you want to delete. The IF EXISTS clause is used to prevent errors if any of the specified databases do not exist.

Please note that dropping databases is a irreversible action and all data in the databases will be permanently deleted. Make sure you have a backup before running the command.

How to efficiently drop databases that share a prefix in PostgreSQL?

To efficiently drop databases that share a prefix in PostgreSQL, you can use the following steps:

1. Connect to your PostgreSQL database server using a tool such as psql or pgAdmin.
2. Run the following query to list all the databases that share a common prefix:

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SELECT datname FROM pg_database WHERE datname LIKE 'prefix%';

Replace 'prefix' with the common prefix shared by the databases you want to drop.

1. Verify the list of databases returned by the query and ensure that they are the ones you want to drop.
2. Run the following query to drop the databases:

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DO $$ DECLARE
    r RECORD;
BEGIN
    FOR r IN SELECT datname FROM pg_database WHERE datname LIKE 'prefix%' LOOP
        EXECUTE 'DROP DATABASE ' || quote_ident(r.datname);
    END LOOP;
END $$;

Replace 'prefix' with the common prefix shared by the databases you want to drop.

1. Once the query is executed, the databases with the specified prefix will be dropped.

Please note that dropping databases is a permanent action and cannot be undone, so make sure you have backed up any important data before proceeding.

How to drop all databases that match a certain pattern using SQL commands in PostgreSQL?

To drop all databases that match a certain pattern using SQL commands in PostgreSQL, you can use the following steps:

1. First, connect to the PostgreSQL database as a superuser or a user with sufficient privileges to drop databases.
2. Use the following query to generate a list of databases that match the desired pattern:

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SELECT datname FROM pg_database WHERE datname LIKE 'pattern%';

Replace 'pattern%' with the desired pattern that you want to match.

1. Iterate over the result set from the query and for each database, run the following command to drop the database:

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DROP DATABASE database_name;

Replace 'database_name' with the name of the database you want to drop.

1. Repeat step 3 for each database that matched the pattern in step 2.
2. Once you have dropped all the databases that match the desired pattern, you can verify by running the query in step 2 again to ensure no databases remain with that pattern.

Please note that dropping databases is a destructive operation and should be done with caution. Make sure to backup any important data before executing these commands.

What is the quickest way to delete several databases in PostgreSQL at once?

The quickest way to delete several databases in PostgreSQL at once is by using the drop database command with a wildcard to match the databases you want to delete.

For example, if you want to delete databases with names starting with "test_", you can use the following command:

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DROP DATABASE IF EXISTS test_*;

This will delete all databases that match the pattern "test_*". Please make sure to double-check the pattern to avoid accidentally deleting any databases you want to keep.