In this post, I am sharing complete steps for moving main PostgreSQL data directory to any new location in Linux.

When we install PostgreSQL on Linux operating system, by default it stores in “/var/lib/postgresql/[version]/data/”

Always best practice is to store database data on the separate drive instead of the system drives.

Check the current data directory:

postgres=# SHOW data_directory;

        data_directory
------------------------------
 /var/lib/postgresql/9.6/main

Stop the PostgreSQL Service:

sudo systemctl stop postgresql

Create a new directory:

mkdir postgres_data_dir

Give directory ownership to your Linux user:

chown user_name postgres_data_dir

Move existing PostgreSQL data/floder to the new location:

sudo rsync -av /var/lib/postgresql /test/postgres_data_dir/

Move old folder to the backup folder:

sudo mv /var/lib/postgresql/9.6/main /tmp/pg_backup

Change data folder in postgresql.conf file:

data_directory = '/test/postgres_data_dir/postgresql/9.6/main'

Start the service of PostgreSQL:

sudo systemctl start postgresql

Now check the data directory:

postgres=# SHOW data_directory; 

 		  data_directory
--------------------------------------------
/test/postgres_data_dir/postgresql/9.6/main

In this post, I am showing the installation process of MySQL Tuner in Ubuntu 16.04.
MySQL Tuner is a useful tool that will connect to a running MySQL instance and offer suggestions for how it can be configured for your workload.

You can use this tool for running production server as well, and it will give you different types of Performance Metrics and Server statistics like about the Storage, Security, Performance Parameters, Cache Parameters, InnoDB Settings, MyISAM Settings and more.

Install MySQL Tuner in Ubuntu 16.04:

sudo apt-get install mysqltuner

Execute MySQL Tuner:

mysqltuner

Here, I am also sharing the sample result of my test server on which I installed and executed MySQL Tuner.

-------- Storage Engine Statistics -------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MRG_MYISAM
[--] Data in InnoDB tables: 16K (Tables: 1)
[OK] Total fragmented tables: 0

-------- Security Recommendations  -------------------------------------------
[OK] There is no anonymous account in all database users
ERROR 1054 (42S22) at line 1: Unknown column 'password' in 'where clause'
[OK] All database users have passwords assigned
ERROR 1054 (42S22) at line 1: Unknown column 'password' in 'where clause'

-------- Performance Metrics -------------------------------------------------
[--] Up for: 4d 17h 35m 56s (26 q [0.000 qps], 32 conn, TX: 21K, RX: 5K)
[--] Reads / Writes: 100% / 0%
[--] Binary logging is disabled
[--] Total buffers: 192.0M global + 1.1M per thread (151 max threads)
[OK] Maximum reached memory usage: 194.1M (19.60% of installed RAM)
[OK] Maximum possible memory usage: 352.4M (35.58% of installed RAM)
[OK] Slow queries: 0% (0/26)
[OK] Highest usage of available connections: 1% (2/151)
[!!] Aborted connections: 43.75%  (14/32)
[!!] Query cache is disabled
[OK] Temporary tables created on disk: 15% (10 on disk / 64 total)
[OK] Thread cache hit rate: 93% (2 created / 32 connections)
[OK] Table cache hit rate: 25% (28 open / 109 opened)
[OK] Open file limit used: 0% (6/1K)
[OK] Table locks acquired immediately: 100% (100 immediate / 100 locks)

-------- MyISAM Metrics -----------------------------------------------------
[!!] Key buffer used: 18.2% (3M used / 16M cache)
[OK] Key buffer size / total MyISAM indexes: 16.0M/43.0K
[!!] Read Key buffer hit rate: 50.0% (6 cached / 3 reads)

-------- InnoDB Metrics -----------------------------------------------------
[--] InnoDB is enabled.
[OK] InnoDB buffer pool / data size: 128.0M/16.0K
[OK] InnoDB buffer pool instances: 1
[!!] InnoDB Used buffer: 3.55% (291 used/ 8191 total)
[!!] InnoDB Read buffer efficiency: 81.34% (1120 hits/ 1377 total)
[!!] InnoDB Write buffer efficiency: 0.00% (0 hits/ 1 total)
[OK] InnoDB log waits: 0.00% (0 waits / 2 writes)

-------- AriaDB Metrics -----------------------------------------------------
[--] AriaDB is disabled.

-------- Replication Metrics -------------------------------------------------
[--] No replication slave(s) for this server.
[--] This is a standalone server..

PostgreSQL recently launched the new pgAdmin 4 tool to access the PostgreSQL Database Server.
In this post, I am sharing steps to install pgAdmin 4 desktop mode in Ubuntu 16.04.

First, create a virtual environment:

sudo apt-get install virtualenv python-pip libpq-dev

Create pgadmin4 virtual environment:

cd
virtualenv pgadmin4

Now, go to pgadmin4 and activate it:

cd pgadmin4
source bin/activate

Download the pgadmin4:

wget https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v1.4/pip/pgadmin4-1.4-py2.py3-none-any.whl

Just check the pgadmin4:

ls -ltr
 
postgres@ip-172-31-27-19:~/pgadmin4$ ls -ltr
total 24
drwxrwxr-x 3 postgres postgres 4096 Jul 18 20:07 lib
drwxrwxr-x 2 postgres postgres 4096 Jul 18 20:07 include
drwxrwxr-x 3 postgres postgres 4096 Jul 18 20:07 share
drwxrwxr-x 2 postgres postgres 4096 Jul 18 20:07 local
-rw-rw-r-- 1 postgres postgres   60 Jul 18 20:07 pip-selfcheck.json
drwxrwxr-x 2 postgres postgres 4096 Jul 18 20:07 bin

Now install pgadmin4:

pip install pgadmin4-1.4-py2.py3-none-any.whl

Do activate:

cd ~/pgadmin4
source bin/activate

Execute require python script:

python lib/python2.7/site-packages/pgadmin4/pgAdmin4.py

Check the output:

pgAdmin 4 - Application Initialisation
======================================
The configuration database - '/var/lib/postgresql/.pgadmin/pgadmin4.db' does not exist.
Entering initial setup mode...
NOTE: Configuring authentication for SERVER mode.
 
Enter the email address and password to use for the initial pgAdmin user account:
 
Email address: anveshpatel88@gmail.com
Password:
Retype password:
Password must be at least 6 characters. Please try again.
Password:
Retype password:
 
The configuration database has been created at /var/lib/postgresql/.pgadmin/pgadmin4.db
Starting pgAdmin 4. Please navigate to http://localhost:5050 in your browser.

Access pgadmin4 in a browser:

http://localhost:5050

In this post, I am sharing primary steps to install MySQL 5.7 on Ubuntu 16.04.
Please follow the below steps, and get ready with MySQL 5.7 in few minutes.

Step 1: Update the server package

sudo apt-get update

Step 2: Install latest MySQL Server from updated package

sudo apt-get install mysql-server

Step 3: Ask for Root user password, so enter your Root password and press OK

Step 4: Make sure about default MySQL Security Options

sudo mysql_secure_installation

For testing, I passed below options:

Step 5: Check the MySQL Service Status

systemctl status mysql.service

Step 6: Connect MySQL using root user

mysql -u root -p

Step 7: Final – Check the version details

mysql> select version();
+-------------------------+
| version()               |
+-------------------------+
| 5.7.18-0ubuntu0.16.04.1 |
+-------------------------+

PostgreSQL is a powerful, open source object-relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness.
 
I am going to share few steps to install PostgreSQL 9.6 on Ubuntu 16.04.

First, check the version of Ubuntu:

lsb_release -sc

sudo add-apt-repository "deb https://apt.postgresql.org/pub/repos/apt/ trusty-pgdg main"

sudo apt-get update
sudo apt-get install postgresql-9.6

ubuntu@:~$ sudo passwd postgres
Enter new UNIX password:****
Retype new UNIX password:****
passwd: password updated successfully

sudo service postgresql start

ubuntu@:~$ su postgres
Password:****

createdb database_name

psql -d database_name

create table Test (rno integer);

\q

exit