DB Wiki
https://www.dbwiki.co.uk/
2026-11-08T15:50:37+00:00DB Wiki
https://www.dbwiki.co.uk/
https://www.dbwiki.co.uk/_media/wiki/dokuwiki.svgtext/html2026-10-21T14:27:51+00:00Anonymous (anonymous@undisclosed.example.com)syntax - created - external edit
https://www.dbwiki.co.uk/wiki/syntax?rev=1792592871&do=diff
Formatting Syntax
DokuWiki supports some simple markup language, which tries to make the datafiles to be as readable as possible. This page contains all possible syntax you may use when editing the pages. Simply have a look at the source of this page by pressingtext/html2026-04-20T10:24:37+00:00z0hpvk (z0hpvk@undisclosed.example.com)linuxcommands
https://www.dbwiki.co.uk/linuxcommands?rev=1776680677&do=diff
Linux Commands
Memory
dmidecode -t 17 | grep "Size:"
grep Mem /proc/meminfo
grep Swap /proc/meminfo
grep HugePages_ /proc/meminfo
Processor
grep name /proc/cpuinfo | uniq
grep process /proc/cpuinfo | wc -l
Services
journalctl -u <Service_Name> -n 100 -f
systemctl list-unitstext/html2026-04-20T09:57:11+00:00z0hpvk (z0hpvk@undisclosed.example.com)start
https://www.dbwiki.co.uk/start?rev=1776679031&do=diff
Database Wiki
PostgreSQL Articles
PostgreSQL Information
PostgreSQL Replication
PostgreSQL Partitioning
PostgreSQL Barman
PostgreSQL Upgrades
PostgreSQL Extensions
PostgreSQL Vacuum
PostgreSQL pl/pgpsql
PostgreSQL Flexible Server for Azure
Python and PostgreSQL
Terraform and PostgreSQL
Grand National Sweepstake Code
IMDB Database
----------
Oracle Database Articles
Automatic Diagnostic Repository
Character Sets
Cloud Control 12c
Database Auditing
Data Guard
Da…text/html2026-01-22T13:26:03+00:00z0hpvk (z0hpvk@undisclosed.example.com)cybertec_migrator-enterprise-v3.20.3-amd64.tar.gz - removed
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<img src="https://www.dbwiki.co.uk/lib/images/fileicons/svg/gz.svg" alt="cybertec_migrator-enterprise-v3.20.3-amd64.tar.gz" loading="lazy" width="500" height="500" />text/html2025-08-07T09:11:21+00:00z0hpvk (z0hpvk@undisclosed.example.com)usefulscripts
https://www.dbwiki.co.uk/usefulscripts?rev=1754557881&do=diff
Scripts
Tablespaces / Data Files / Blocks
SET PAGESIZE 140 LINESIZE 200
COLUMN used_pct FORMAT A11
COLUMN size_mb FORMAT 9,999,999
COLUMN free_mb FORMAT 9,999,999
COLUMN max_size_mb FORMAT 9,999,999
COLUMN max_free_mb FORMAT 9,999,999
SELECT tablespace_name,
size_mb,
free_mb,
max_size_mb,
max_free_mb,
TRUNC((max_free_mb/max_size_mb) * 100) AS free_pct
FROM (
SELECT a.tablespace_name,
b.size_mb,
a.free_mb,
…text/html2025-06-03T08:11:58+00:00z0hpvk (z0hpvk@undisclosed.example.com)instantclient
https://www.dbwiki.co.uk/instantclient?rev=1748938318&do=diff
Oracle Instant Client
Installation
sudo apt install -y libaio1
mkdir oracle && cd "$_"
wget https://download.oracle.com/otn_software/linux/instantclient/2370000/instantclient-basic-linux.x64-23.7.0.25.01.zip
wget https://download.oracle.com/otn_software/linux/instantclient/2370000/instantclient-sqlplus-linux.x64-23.7.0.25.01.zip
wget https://download.oracle.com/otn_software/linux/instantclient/2370000/instantclient-sdk-linux.x64-23.7.0.25.01.zip
wget https://download.oracle.com/otn_software/…text/html2025-04-17T10:16:53+00:00z0hpvk (z0hpvk@undisclosed.example.com)postgresqlcommands
https://www.dbwiki.co.uk/postgresqlcommands?rev=1744885013&do=diff
Installation
Linux
<https://www.postgresql.org/download/linux/debian/>
<https://www.postgresql.org/download/linux/redhat/>
Create Cluster
The Debian or Ubuntu installation will create a default instance.
Create new instances using the commands below ...
# Debian / Ubuntu
pg_createcluster -d /var/lib/postgresql/17/main 17 main
# Redhat / Fedora
# Default Data Directory: /var/lib/pgsql/17/data
sudo /usr/pgsql-17/bin/postgresql-17-setup initdb
/usr/pgsql-17/bin/initdb -D /var/lib/pgsql…text/html2025-04-01T08:34:31+00:00z0hpvk (z0hpvk@undisclosed.example.com)performancetuning
https://www.dbwiki.co.uk/performancetuning?rev=1743496471&do=diff
Performance Tuning
Simple Explain Plan
EXPLAIN PLAN FOR SELECT * FROM dba_users;
SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY);
Get Active Sessions
SET LINES 2000 TRIMSPOOL ON PAGES 10000
COLUMN EVENT FORMAT A30
COLUMN secw FORMAT 99999
COLUMN username FORMAT A15
COLUMN sqlid_chno FORMAT A20
ACCEPT usr PROMPT 'Username (blank for all): '
SELECT sw.SID,
s.username,
sw.SEQ#,
sw.EVENT,
sw.WAIT_TIME,
sw.SECONDS_IN_WAIT secw,
SQL_ID||' '||SQL_CHILD_NUMBER sqlid_chno,
sw.STATE,…