The Penguinlinux.com Blog

The CentOS Team is pleased to announce the official release of CentOS 3.4 for i386.

This release includes all RHEL 3 updates (for U4) and errata up to January 5th, 2005. New ISO images are available as well as an installable DVD edition with source. In addition this release is available via BitTorrent.
Continua”Centos 3.4 release notes”

this is the part that taught me how to change access permissions to my database.

I was able to create 2 users one with full rights and the other with only a few rights.

the users postgres still has access to the database but you have to su -l postgres as root user to access the database as the postgres user.
Continua”How to control access with PostgreSQL”

Another guide to optimize the PostgreSQL server.

In our tests, the default PostgreSQL settings are not optimized. This page outlines many of the optimization steps we and our customers have used to tune PostgreSQL for use with ListManager.
Continua”Simple Tuning PostgreSQL”

PostgreSQL µHowTo
Alexander Krumpholz, 28 February 2002.

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Introduction
PostgreSQL is a relational database management system.
PostgreSQL is free and the complete source is available.
PostgreSQL’s actual version is 7.2. (Feb 2002)
Continua”Quick Dirty Guide to PostgreSQL”

Performance tuning for PostgreSQL database
PostgreSQL can be a very fast database, but its default settings are very conservative. Very simple adjustments can improve its performance dramatically.
Continua”simple Tuning PostgreSQL database tutorial”

PostgreSQL Performance Tuning
By Bruce Momjian on Tue, 2001-07-31 23:00.

Tweak your hardware to get the most from this open-source database.
PostgreSQL is an object-relational database developed on the Internet by a group of developers spread across the globe. It is an open-source alternative to commercial databases like Oracle and Informix.
Continua”PostgreSQL performance Tuning”

I was given the task of installing a PostgreSQL server at the office so we can test it an learn more about it.

I downloaded the sources and wrote this instructions for future reference.

This instructions can apply to redhat 7.3 , 8 or 9.

Right now I am using centos 3.4 for this install but I don’t see why this should not work on another system. This is a work in progress so things can change all the time. This is for personal reference and you are free to use this information if interested.
Continua”Installation of PostgreSQL 8.0.3″

2.10.3. Upgrading from Version 3.23 to 4.0
In general, you should do the following when upgrading to MySQL 4.0 from 3.23:

Check the items in the change list found later in this section to see whether any of them might affect your applications. Note particularly any that are marked Incompatible change; these result in incompatibilities with earlier versions of MySQL.
Continua”Upgrade Mysql 3.2 to 4.0″

by Jeff Hunter, Sr. Database Administrator

Overview

This article presents the commands used to partition and format a second hard drive in Linux using the ext3 file system. For the purpose of this example, I installed a second hard drive in a Red Had Linux system where the drive is recognized as /dev/hdb. I want to make only one partition on this hard drive which will be /dev/hdb1.
fdisk
First, you will need to run the fdisk command in order to partition the disk. For this example, I only want to create one ext3 partition. Here is an example session:
[root@linux2 etc]# fdisk /dev/hdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won’t be recoverable.
Continua”Partitioning and Formatting Second Hard Drive - (ext3)”

I needed to change some text inside a file. Actually multiple files and I did not know an easy way to do it. I searched online and I came accross a little simple one liner.

This is based in this question that was posted on a message board.

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I am trying to do a search on an entire directory, finding all the instances of the text “applicationX” and replacing all instances with the text “applicationY”.

I created the following to find all instances and print the files that contain the search text. But now I don’t know how to replace the text.

find . -type f -exec grep “applicationX” {} \; -print

Please help..thanks

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An here is the reply where I found the one liner.

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or you could just aswell use PERLs inplace replacement (http://www.spiration.co.uk/post/522) as in the following one-liner:

find /path/to/start/from/ -type f | xargs perl -pi -e ’s/applicationX/applicationY/g’

christo

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This is based on this post .

To replace all occurences of the word “hello” with the word “harrow” in files in the current directory, use perl’s in-place substitusion from the command line as follows:

perl -pi -e ’s/hello/harrow/g’ *.txt

note, the ‘g’ at the end makes it match [gredily|globally] - ie it will to multiple matches in a single line. You can add an ‘i’ for case insensitivity.

Full regular expressions can be used, and the *.txt can of course be *.html, *.anything, or just *

christo
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I used that one line and changed to match my settings and I created a simple txt file with the Words March and I wanted to change it to April

I changed the one line to

find -type f | xargs perl -pi -e ’s/March/April/g’

and I ran that one liner inside the folder where I had my text file and it changed all the instances of March to April.

:)

I am keeping this tip on this blog to remind myself if I even need to do this again.