restore_pg_database.sh

#!/bin/bash

processors=$(cat /proc/cpuinfo | awk '/^processor/{print $3}' | wc -l)

# Usage information
if [ $# -ne 2 ]
then
        echo "Usage: $0 <source_file> <dbname>"
        echo
        echo "This script will restore the requested database from the given source file."
        exit 1
fi

# Ensure the source file is valid
if [ ! -f "$1" ]
then
        echo "The source file $1 does not exist."
        exit 2
fi

# Close all connections to the requested database
echo "Closing connections to database $2..."
psql -c "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname='$2'"

# Check if database exists
found=$(psql -Altc "SELECT datname FROM pg_database WHERE NOT datistemplate AND datallowconn AND datname != 'postgres' AND datname = '$2';")

# Drop the database if it exists
if [ "${found[0]}" = $2 ]
then
        echo "Dropping database $2..."
        dropdb "$2"
fi

# Create the database
echo "Creating database $2..."
createdb -T template0 "$2"

# Restore the contents of the database
echo "Restoring database $2..."
pg_restore -d "$2" -j $processors -v $1