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Displaying posts with tag: perl (reset)
Understanding the maximum number of columns in a MySQL table

This post was initially going to be two sets of polls: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read on, ponder those questions and come up with your own answers… and see if you’re right or can prove me wrong!

Back in 2009, I finished what seemed an epic task in the Drizzle code base: banishing the FRM file. Why? We felt it was not a good idea to keep arbitrary and obscure limitations from the 1980s alive in the 21st century and instead wanted a modular system where the storage engines themselves owned their own metadata. This was a radical departure from the MySQL philosophy, and one that has truly paid off in the Drizzle code base. However… for those using MySQL, Percona Server, MariaDB or any other of the MySQL branches/forks, you …

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[updated] Free book February returns – Get a copy of the InnoDB Quick Reference Guide

This month is a special month. It’s not because of President’s Day or even the exciting day where we revel in groundhogs. No, this month is special because the free book give-away is happening again. This is where you, the reader, gets to win something free for doing nothing more than posting a comment saying that you want a copy of my recently published book – The InnoDB Quick Reference Guide from Packt Publishing. The book is a great reference for DBAs, PHP, Python, or Perl programmers that integrate with MySQL and want to learn more about the InnoDB database engine.

So, all you have to do is post a comment here saying that you want a copy and write out a single (or more) sentence about how you use InnoDB in your development or production environment. At the end of the month two readers will be chosen via a random list sorting script that …

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The InnoDB Quick Reference Guide is now available

I’m pleased to announce that my first book, the InnoDB Quick Reference Guide, is now available from Packt Publishing and you can download it by clicking here. It covers the most common topics of InnoDB usage in the enterprise, including: general overview of its use and benefits, detailed explanation of seventeen static variables and seven dynamic variables, load testing methodology, maintenance and monitoring, as well as troubleshooting and useful analytics for the engine. The current version of MySQL ships with InnoDB as the default table engine, so whether you program your MySQL enabled applications with PHP, Python, Perl or otherwise, you’ll likely benefit from this concise but comprehensive reference guide for InnoDB databases.

Here are the chapter overviews …

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Connect to MySQL with Perl using DBI

Example of a connection to MySQL with Perl using DBI

 
#! /usr/bin/perl -w
#
#  Example code to connect to MySQL, create a table, fill it with some data and select it again.
#
#  To install DBI using cpan:
#
#  perl -MCPAN -e shell
#  cpan> install DBI
#  cpan> install DBD::mysql
#

use strict;
use DBI;

my $database = "test";
my $user = "user";
my $passwd = "secret";
my $sqlCreate = "CREATE TABLE IF NOT EXISTS test ( pkey int(11) NOT NULL auto_increment, a int, b int, c int, timeEnter timestamp(14), PRIMARY KEY  (pkey) ) ";

my $insert = "insert into test (a,b,c) values (1,2,3),(4,5,6),(7,8,9)"; 
my $select = "select a,b,c from test"; 
my $dsn = "DBI:mysql:host=localhost;database=${database}";
my $dbh = DBI->connect ($dsn, $user, $passwd) or die "Cannot connect to server\n";

# Execute the sql to create the table test
my $stmnt = $dbh->prepare($sqlCreate);
$stmnt->execute();

# Insert the testdata
$stmnt = $dbh->prepare($insert); …
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Retrieving List of MySQL Users and Grants with Perl

Before I upgrade MySQL to the latest and greatest version, one of the first things that I do is export the user and grant information. In the past, I would keep all of my user information (user name, password, grants) in a text file, with the SQL for each user/grant ready to be executed on the upgraded server. I did use my own form of “mental encryption” for my passwords, so the passwords weren’t in plain English. But then I would have to decode my passwords each time before I executed the SQL statements.

When I upgrade, I usually like to dump all of the data and import it into the new version, so I have a fresh copy of the database. The MySQL server that I have is for my personal use and the data size is relatively small, so for my case it doesn’t take long to import the data.

But there were times when I would add a user in the MySQL database and forget to add it to my text file. Then, when it came time to upgrade and I …

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Installing MySQL MHA with Percona Server

MySQL MHA by Oracle ACE Director Yoshinori Matsunobu is an excellent open source tool to help in providing HA with native MySQL replication. The installation however is dependent on some Perl packages and to the untrained eye this may be an issue if you are using Percona Server as your choice of MySQL implementation.

The MHA Node page requires the perl-DBD-MySQL package to be installed. The installation on RedHat/CentOS/Oracle Linux look like this:

$ sudo yum install perl-DBD-MySQL
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirror.anl.gov
* extras: mirror.anl.gov
* updates: mirror.anl.gov
Setting up Install Process
Resolving Dependencies
--> Running transaction check …
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Simple MySQL: Converting ANSI SQL to SQLite3

I was digging through some old project code and found this script. Sometimes one finds oneself in an odd situation and needs to convert regular SQL, say from a MySQL database dump, into SQLite3 format. There’s not too much else to say, but here is a script that helps with the process. It can likely be improved but this handles the items that came up during conversion on initial runs.

#!/bin/sh
####
# NAME: convert-mysql-to-sqlite3.sh
# AUTHOR: Matt Reid
# DATE: 2011-03-22
# LICENSE: BSD
####
if [ "x$1" == "x" ]; then
   echo "Usage: $0 "
   exit 
fi 
cat $1 |
grep -v ' KEY "' |   
grep -v ' UNIQUE KEY "' |
grep -v ' PRIMARY KEY ' |
sed '/^SET/d' |          
sed 's/ unsigned / /g' | 
sed 's/ auto_increment/ primary key autoincrement/g' |
sed 's/ smallint([0-9]*) / integer /g' | 
sed 's/ tinyint([0-9]*) / integer /g' |  
sed 's/ int([0-9]*) / integer /g' |      
sed 's/ character set [^ ]* / /g' |      
sed 's/ enum([^)]*) / varchar(255) /g' | 
sed 's/ on …
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Verifying a Socket w/Perl

Using a lowercase hostname is typical but I got sloppy on a Windows 7 installation, after all Windows is case insensitive, and I used a mixed case hostname. It raised an interesting error when installing Oracle Database 11g Release 2.

Enterprise manager configuration failed due to the following error -

Failed to allocate port(s) in the specified range(s) for the following process(es): JMS
[5540-5559], RMI [5520-5539], Database Control [5500-5519], EM Agent [3938] | [1830-1849]

Refer to the log file at C:\app\McLaughlinM\cfgtoollogs\dbca\orcl\emConfig.log for more details.

You can retry configuring this database with Enterprise Manager later by manually running C:\app\McLaughlinM\product\11.2.0\dbhome_1\bin\emca script.

After verifying the ports …

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Linus on Instantiation and Armadaification

I feel a sense of pride when I think that I was involved in the development and maintenance of what was probably the first piece of software accepted into Debian which then had and still has direct up-stream support from Microsoft. The world is a better place for having Microsoft in it. The first operating system I ever ran on an 08086-based CPU was MS-DOS 2.x. I remember how thrilled I was when we got to see how my friend’s 80286 system ran BBS software that would cause a modem to dial a local system and display the application as if it were running on a local machine. Totally sweet.

When we were living at 6162 NE Middle in the nine-eight 292, we got an 80386 which ran Doom. Yeah, the original one, not the fancy new one with the double barrel shotgun, but it would probably run that one, too. It was also …

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The blog was down yesterday

The brief outage was due to a scheduled move of the servers to a separate rack and subnet dedicated to our work with the Center for Information Assurance & Cybersecurity (ciac) at the University of Washington Bothell (uwb), and a11y.com

I am currently exercising the new (to us) equipment and hope to winnow the less than awesome equipment over the next quarter. I spent the last six months finding the best in breed of the surplussed DL385 and DL380 chassis we (work) were going to have recycled. The team and I were able to find enough equipment to bring up one of each with eight and six gigs of memory, respectively. These will make excellent hypervisors for provisioning embedded instances of Slackware, Fedora, RHEL, CentOS, Debian, FreeBSD, OpenSolaris, OpenIndiana, FreeDOS, etc.

When I initially configured this xen paravirt environment, I failed to plan for integration with libvirt, so I am now re-jiggering the software bridges so …

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