Contents

• PostgreSQL Workload Analyzer detailled installation guide
  • Download powa-archivist from the website
  • Unpack the downloaded file
  • Compile and install the software
  • Create a PoWA database and create required extensions
  • Modify the configuration files
  • Restart PostgreSQL
  • Upgrading from a previous version of PoWA

PostgreSQL Workload Analyzer detailled installation guide

Read README.md and the official documentation for further details about PoWA.

PoWA requires PostgreSQL 9.5 or more. This documentation assumes you’re using the version 15 of PostgreSQL.

The following documentation describes the detailed installation steps to install PoWA.

Download powa-archivist from the website

The latest stable version should be used. It can be downloaded from github.

This documentation assumes that the version is 4.2.2, and you downloaded the .zip file.

Unpack the downloaded file

cd /usr/src
unzip powa-REL_4_2_2.zip

Compile and install the software

Before proceeding, be sure to have a compiler installed and the appropriate PostgreSQL development packages. Something like

apt-get install postgresql-server-dev-15

or

yum install postgresql94-devel

Then:

cd /usr/src/powa-REL_4_2_2
make

If everything goes fine, you will have this kind of output :

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -fpic -I. [...]   -c -o powa.o powa.c
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -fpic [...] -shared -o powa.so powa.o

Install the software :

• This step has to be made with the user that has installed PostgreSQL. If you have used a package, it will be certainly be root. If so:

sudo make install

Else, sudo into the user that owns your PostgreSQL executables, and

make install

It should output something like the following :

/bin/mkdir -p '/usr/pgsql-15/share/extension'
/bin/mkdir -p '/usr/pgsql-15/share/extension'
/bin/mkdir -p '/usr/pgsql-15/lib'
/bin/mkdir -p '/usr/pgsql-15/share/doc/extension'
/usr/bin/install -c -m 644 ./powa.control '/usr/pgsql-15/share/extension/'
/usr/bin/install -c -m 644 ./powa--2.0.1.sql ./powa--2.0-2.0.1.sql ./powa--3.0.0.sql '/usr/pgsql-15/share/extension/'
/usr/bin/install -c -m 755  powa.so '/usr/pgsql-15/postgresql-15.7/lib/'
/usr/bin/install -c -m 644 ./README.md '/usr/pgsql-15/share/doc/extension/'

Create a PoWA database and create required extensions

Note: if you are upgrading from a previous PoWA release, please consult the upgrading section at the end of this file.

First, connect to PostgreSQL as administrator :

bash-4.1$ psql
psql (9.3.5)
Type "help" for help.
postgres=# create database powa;
CREATE DATABASE
postgres=# \c powa
You are now connected to database "powa" as user "postgres".
powa=# create extension pg_stat_statements ;
CREATE EXTENSION
powa=# create extension btree_gist ;
CREATE EXTENSION
powa=# create extension powa;
CREATE EXTENSION
powa=# \dt
                          List of relations
 Schema |              Name               | Type  |  Owner
--------+---------------------------------+-------+----------
 public | powa_functions                  | table | postgres
 public | powa_last_aggregation           | table | postgres
 public | powa_last_purge                 | table | postgres
 public | powa_statements                 | table | postgres
 public | powa_statements_history         | table | postgres
 public | powa_statements_history_current | table | postgres
 [...]

Modify the configuration files

In postgresql.conf:

Change the shared_preload_libraries appropriately :

shared_preload_libraries = 'powa,pg_stat_statements'# (change requires restart)

If possible (check with pg_test_timing), activate track_io_timing on your instance, in postgresql.conf:

track_io_timing = on

Other GUC variables are available. Read README.md for further details.

In pg_hba.conf:

Add an entry if needed for the PostgreSQL user(s) that need to connect on the GUI. For instance, assuming a local connection on database powa, allowing any user:

host powa all 127.0.0.1/32 md5

Restart PostgreSQL

As root, run the following command :

service postgresql-9.3 restart

PostgreSQL should output the following messages in the log files :

2014-07-25 03:48:20 IST LOG:  registering background worker "powa"
2014-07-25 03:48:20 IST LOG:  loaded library "powa"
2014-07-25 03:48:20 IST LOG:  loaded library "pg_stat_statements"

Upgrading from a previous version of PoWA

If you already have an older PoWA installation, you can simply upgrade PoWA with the following steps :

First, connect to PostgreSQL as administrator and update the extension :

bash-4.1$ psql powa
psql (9.3.5)
Type "help" for help.
powa=# ALTER EXTENSION powa UPDATE ;
ALTER EXTENSION

However, due to a lot of changes in the data storage, it’s not possible to update to PoWA 3.0.0. In this case, you need to drop and create the extension.

Next, you will need to restart PostgreSQL in order to take account of the updated background worker. As root, run the following command :

service postgresql-15 restart