http://datareign.co.uk/ 2010-07-15T08:25:54+01:00 http://datareign.co.uk/ http://datareign.co.uk/lib/images/favicon.ico text/html 2009-01-20T10:29:13+01:00 http://datareign.co.uk/doku.php?id=1978_pertec_pcc-2000&rev=1232447353&do=diff The first mass market usable home computer, well, let's be honest here, the first computer that could be built and used for something by a reasonably determined enthusiast, was the MITS Altair, the design of which was presented in the American magazine Popular Electronics in January 1975. It had been developed by Edward Roberts, William Yates and Jim Bybee over the previous two years and it burst upon the nerdish world rather like a new sun. text/html 2009-01-20T18:52:57+01:00 http://datareign.co.uk/doku.php?id=1979_acorn_system_1&rev=1232477577&do=diff Britain took a little longer to get into the microcomputer revolution than the U.S. but when it did, the large pool of British engineers and entrepreneurs produced a wide variety of designs. With a smaller population and a lower average income, buyers in the U.K. tended to want cheaper and more open designs than their U.S. counterparts, which led to a proliferation of machines that were somewhat more basic than those across the Atlantic. text/html 2009-01-05T12:12:33+01:00 http://datareign.co.uk/doku.php?id=1979_hewlett-packard_hp-85&rev=1231157553&do=diff By the end of the 'seventies, the 'wild west' atmosphere of the early days of personal computing was beginning to dissipate and established companies were getting into the act. Among the most influential of these was Hewlett-Packard, a company with its roots deep in the electronics business and a strong track record of innovation. text/html 2009-01-20T18:43:47+01:00 http://datareign.co.uk/doku.php?id=1979_sharp_mz-80k&rev=1232477027&do=diff By the beginning of 1979, even the least astute observers of the electronics scene were becoming aware of one important fact: the home computer was here to stay. It was, essentially, an idea whose time had come. At this stage, the three big players were Apple, Commodore and Radio Shack with the Apple, Pet and TRS-80 respectively. MITS, the company that had started it all with the Altair, had been absorbed by Pertec and effectively disappeared. There were several other companies in the field but… text/html 2009-01-05T12:29:40+01:00 http://datareign.co.uk/doku.php?id=1983_sharp_mz-80b&rev=1231158580&do=diff In 1981, IBM launched the PC and the world of computing was never the same again. Well, not quite. It actually took some years for the PC architecture to dominate the desktop and, in the interim, many manufacturers presented alternative views of the way things should go. One such manufacturer was the Japanese Sharp Electronics company whose MZ series had already enjoyed considerable success both in Japan and in Europe. The MZ-80K and its successor the MZ-80B had proved that Sharp knew a thing … text/html 2009-01-19T23:07:04+01:00 http://datareign.co.uk/doku.php?id=1984_apple_macintosh&rev=1232406424&do=diff 1984 was the year in which George Orwell's eponymous novel seemed set to come true, at least in the world of computing. The beige tide of IBM PCs was rolling over the desktop and drowning the one-time diversity of computer design. But in December 1983, an advertisement had appeared in cinemas across America featuring an athletic young woman who, bursting into an auditorium full of gray drones, smashed Big Brother's image with a hammer. It was a blow that was to be heard around the world. text/html 2009-01-21T18:02:30+01:00 http://datareign.co.uk/doku.php?id=ab_initio&rev=1232560950&do=diff Ab Initio consists of a run-time (the Co>Operating System) and a range of support tools. The product is aimed at customers who need to process massive amounts of data and is generally run on very large machines with multiple processors. It is pretty well unheard of for Ab Initio to be used as a stand-alone system. A typical installation will consist of the Co>Operating System running on a multi-processor machine with 4 - 64 nodes. The interface to the system is called 'mp' and this is typically… text/html 2009-01-21T18:01:19+01:00 http://datareign.co.uk/doku.php?id=ab_initio_ad-hoc_multifiles&rev=1232560879&do=diff One common problem in dealing with large amounts of data is that it often arrives in several files, perhaps over a period of time. The classic way of dealing with this is to have a programme which can identify all the files that possess a common record format and use this to feed the files to the appropriate processing. text/html 2009-01-21T18:02:49+01:00 http://datareign.co.uk/doku.php?id=ab_initio_lookup_files&rev=1232560969&do=diff A lookup file is any file which you wish to use as a reference in a graph. It's one of the few components which is generally not connected to any other component. There are only two rules which you need to bear in mind when dealing with lookups. Firstly, lookups have to fit into memory. This implies that a lookup file should contain the bare minimum of data required to perform its task. Strip out unwanted fields and duplicate records, especially if it's a big file to begin with. text/html 2009-01-21T17:57:44+01:00 http://datareign.co.uk/doku.php?id=ab_initio_max_core_variable&rev=1232560664&do=diff Sort components possess a parameter called 'max-core', which controls how much memory is allocated to the sort. There's a certain amount of confusion about setting this variable's value but it is, in essence, subject to some simple rules. If you are fairly sure how many records the sort will handle and that number is significantly smaller than available real memory, then you can set max-core according to the simple formula number of bytes in key * number of records. This will give you the fa… text/html 2009-01-21T17:47:45+01:00 http://datareign.co.uk/doku.php?id=ab_initio_shell_commands&rev=1232560065&do=diff There are various commands distributed as part of the Co>Operating system. * m_mkfs creates a multifile system. As part of this process it creates a number of hidden files which are used to control the file system. * m_rmfs removes a multifile system. Always use this command in preference to the operating system's deletion command to ensure that the correct housekeeping is carried out. * m_mkdir creates a multidirectory. A multidirectory can span several different disks or nodes and cont… text/html 2009-01-21T17:49:42+01:00 http://datareign.co.uk/doku.php?id=ab_initio_shell_variables&rev=1232560182&do=diff There are several shell variables which are used by Ab Initio. Unsurprisingly, they all begin with the prefix AB_ and, as is common Unix practice, are all upper case. It is normal to set all of these in the user's abinitio.rc file. * AB_AIR_ROOT The directory where the EME repository resides * AB_ALLOW_PROJECT_OVERVIEW When this is set, the EME will show the relationship between all graphs and datasets in a project. Deprecated as of version 2.14 * AB_HOME The directory where the Air tool… text/html 2009-01-21T17:59:46+01:00 http://datareign.co.uk/doku.php?id=ab_initio_sort_behaviour&rev=1232560786&do=diff The Sort component's default behaviour is to attempt to perform everything in memory, only spilling data to disk when it exceeds MAX_CORE. It follows that, provided you have plenty of available memory, you should set MAX_CORE to a suitably high value. Sort is optimised to work in parallel and to make use of data as and when it falls out of each incoming flow. text/html 2009-01-21T17:55:44+01:00 http://datareign.co.uk/doku.php?id=ab_inition_gde_components&rev=1232560544&do=diff The Organiser is where the building blocks of an Ab Initio 'graph' may be found and is simply a view of the directory 'Components' under the GDE's home directory. Within the Organiser, components are grouped into more or less logical categories, corresponding to the sub-directories of 'Components'. If the user wishes, it's a simple matter to move the components around, rename groups and generally customise the Organiser to his own needs. text/html 2009-01-13T18:21:20+01:00 http://datareign.co.uk/doku.php?id=accounting_and_finance&rev=1231870880&do=diff I.T. professionals working on any form of accounting or financial system should possess at least a rudimentary understanding of how finance and accounting is supposed to work. At a minimum, check out the Wikipedia entry on accounting, which will provide you with a good, if largely U.S. oriented, overview of the basic principles. text/html 2009-01-23T15:24:47+01:00 http://datareign.co.uk/doku.php?id=activestate_perl&rev=1232724287&do=diff The instructions on the [<http://www.activestate.com/Products/activeperl/> ActivePerl] site are pretty detailed but you need to remember to do the following or nothing will work quite as you planned... * Create a local variable called 'path' for each user. * Copy the complete contents of the system variable 'path' to this local variable. text/html 2009-02-18T11:59:28+01:00 http://datareign.co.uk/doku.php?id=alfresco&rev=1234958368&do=diff Alfresco is an open source document management system. Commercial users can purchase a package (Alfresco Enterprise) while those not looking for commercial support can pick up the current development snapshot, known as Alfresco Labs. The difference is that the non-commercial offering is not guaranteed in any way; just as with any other open source package, you use it at your own risk. text/html 2009-02-17T21:55:57+01:00 http://datareign.co.uk/doku.php?id=alfresco_document_handling&rev=1234907757&do=diff You can add a file to any space to which you have write access. You either have write access because you own the space or because the owner of the space has granted you write access. Using the web interface, you simply log in and then navigate to the space that you wish to use. Clicking on the space's icon will show you existing contents. text/html 2009-02-19T13:41:50+01:00 http://datareign.co.uk/doku.php?id=alfresco_import_with_acpgeneratr&rev=1235050910&do=diff ACPGeneratr is a project contributed by the Deloitte PIER team. Its stated purpose is to provide a tool for bulk uploading into an Alfresco repository. The download explodes into the following structure... ACPGeneratr | --acpGeneratr # The .java and .class files that make up the application. | --content # Place the files to be imported here. | --definition_files # Should contain a .tsv category tree definition and a .csv metadata definition file … text/html 2009-02-06T15:18:23+01:00 http://datareign.co.uk/doku.php?id=alfresco_installation&rev=1233933503&do=diff The current Labs version is pointed to from the front page of the Developers Wiki (see the Alfresco main page). There are currently installation kits for Linux, OS-X and Windows, some of which are pre-configured with a Tomcat web server. The full package is around 300MB, so it can take quite a while to pull down. text/html 2009-02-17T14:51:36+01:00 http://datareign.co.uk/doku.php?id=alfresco_searching&rev=1234882296&do=diff Alfresco includes the powerful Lucene engine to power searching. * Quick Search is implemented by a text box, which is generally available at the top right of every Alfresco web page. If you type a word or phrase into this, Alfresco will find every document that satisfies the string and display them ready to be opened, checked out or otherwise dealt with, depending on your and the item's status. text/html 2009-02-17T15:37:43+01:00 http://datareign.co.uk/doku.php?id=alfresco_spaces&rev=1234885063&do=diff A Space is similar to a directory or folder in an operating system. It is a unit that contains other units and it can be manipulated as a whole or parts of it may be manipulated separately. Spaces may contain other spaces, without practical limit. From the access level, a space is the basic module of security. Both users and groups may have access to the contents of a space and the access is defined as one of 5 levels: text/html 2009-02-18T09:04:10+01:00 http://datareign.co.uk/doku.php?id=alfresco_start_and_stop&rev=1234947850&do=diff As a server, it would be normal practice to bring Alfresco up and, thereafter, leave it running, other than for essential maintenance. Of course, this means that, when Alfresco does need to be restarted, everyone has forgotten how to do it! Which is where this page comes in... text/html 2009-02-18T09:10:44+01:00 http://datareign.co.uk/doku.php?id=alfresco_storage&rev=1234948244&do=diff On Linux, the basic storage scheme is very simple... <host path> | --alfresco | -- alf_data | --audit.contentstore | --contentstore | --contentstore.deleted | --derby_data | --lucene-indexes text/html 2009-02-17T13:59:35+01:00 http://datareign.co.uk/doku.php?id=alfresco_tips_and_traps&rev=1234879175&do=diff Alfresco consists of various components, many of which may require some fine tuning to provide the particular functionality you desire. Basic information about configuration of the Alfresco repository is to be found in this page. The entries below are intended only as a supplement to the extensive information to be found throughout the Alfresco Wiki. text/html 2009-02-06T09:21:36+01:00 http://datareign.co.uk/doku.php?id=alfresco_user_facilities&rev=1233912096&do=diff This page describes the facilities available to users and how they can access and add to content in an Alfresco site. Users can log in to Alfresco from any standard browser by pointing it at one of the following URLs... * URL:8080/alfresco will present the user with a guest dashboard * URL:8080/share presents the user with a login screen text/html 2009-11-30T12:34:37+01:00 http://datareign.co.uk/doku.php?id=algorithms&rev=1259584477&do=diff Also known as “how to”. There are more tips on some of the software pages... Sometimes you have a stream of text that has been created with hard carriage returns at the end of each line. If you view such a file through a display that has a shorter line length than the file lines, you get 'hanging' line ends, which look horrible. text/html 2009-09-27T10:47:09+01:00 http://datareign.co.uk/doku.php?id=apache&rev=1254044829&do=diff Apache servers provide 90% or more of the web's content. The first place to look for answers is the Apache home page. The basic layout for an Apache installation changes a little from system to system. This can cause confusion when you wish to make alterations quickly. The following information may be of assistance. text/html 2010-06-02T09:14:01+01:00 http://datareign.co.uk/doku.php?id=apple_os-x&rev=1275466441&do=diff When Apple released OS-X in 1999, it seemed like an even bet as to whether the change from their proprietory, ROM locked Macintosh OS would break the company. In retrospect, the fears seem baseless. OS-X has made the Apple range of computers highly competitive, as the leaders in the Unix desktop marketplace, largely because remarkably few users even realise that they are using a Unix based system. text/html 2010-06-02T19:06:08+01:00 http://datareign.co.uk/doku.php?id=apple_os-x_processes&rev=1275501968&do=diff A brief overview of some of the processes you may expect to find in the Activity Monitor Process List. We only discuss background processes here. All your foreground running applications (Mail, Safari, etc.) will also appear in the list. In the Stopable? column, the following may appear... text/html 2010-06-27T11:34:47+01:00 http://datareign.co.uk/doku.php?id=apple_os-x_tips&rev=1277634887&do=diff Here are some things we've found useful in real life running. Simply hold down COMMAND-V from when the chime sounds until the log starts to appear. Default application to open a particular file Select the file in a Finder window, Ctrl-Click to get the pop-up menu, click on the arrow next to 'Open With:' to show the dialogue, select the application to use from the selection box (you can use the 'other' item right at the bottom to hunt for an application that isn't on the menu). text/html 2010-06-27T11:32:16+01:00 http://datareign.co.uk/doku.php?id=apple_os-x_web_directory&rev=1277634736&do=diff Pages that we've found usefull in the past... * Open Source Downloads at Apple * What Happens at system startup * Format large Fat32 volumes in Panther * Booting Mac OS X * Disable Aqua at boot time * And another method of disabling Aqua at boot time text/html 2009-01-03T19:16:27+01:00 http://datareign.co.uk/doku.php?id=autosys&rev=1231010187&do=diff Autosys is a corporate scheduling tool that stores control information in a third party database. Operators can define and run schedules through browser, command line or graphic desktop interfaces. For using the command line interface, the Computer Associates web sight maintains a usefull Cheat Sheet text/html 2009-12-07T09:52:58+01:00 http://datareign.co.uk/doku.php?id=awk&rev=1260179578&do=diff Awk comes into its own when you need to do something just a little more sophisticated than standard text editing but don't have the time nor inclination to use Perl or another programming language. A colleague needed to find the length of a particular line in a file. He discovered that using 'wc' gave the wrong result (as in “head -2 filename | tail -1 | wc -c”). Here's what he came up with instead. Note the parentheses... text/html 2009-01-03T18:27:21+01:00 http://datareign.co.uk/doku.php?id=awstats&rev=1231007241&do=diff AWStats is a very effective tool for displaying web server performance statistics, originally written by Laurent Destailleur. It is a Perl script with some small pieces of Javascript. * AWStats General Operation A brief description of how it all works. text/html 2009-01-03T18:46:19+01:00 http://datareign.co.uk/doku.php?id=awstats_change_concepts&rev=1231008379&do=diff Some things to think about when changing AWStats. AWStats is a large and fairly complex system. The following description should be considered as only the briefest introduction to how that system works and what you may need to change to amend the system to your own needs. text/html 2009-01-04T09:08:12+01:00 http://datareign.co.uk/doku.php?id=awstats_general_operation&rev=1231060092&do=diff Some of the important components of the main script may be found in the page AWStats General Operation and important variables are described in the page awstats.pl Variables On Windows systems, AWStats is generally installed inside the Apache2.2 folder. The path to Apache is defined by the environment variable %AWSTATSROOT% (e.g. “E:\Apache2.2”) The components are installed inside the Apache hierarchy as follows... text/html 2009-01-03T18:05:17+01:00 http://datareign.co.uk/doku.php?id=awstats_main_script_overview&rev=1231005917&do=diff At the heart of the AWStats suite is the script awstats.pl. The following description, based on version 1.910 (Dated 2008/04/21 21:13:28) is intended to assist in carrying out changes to awstats.pl. You need to be very carefull when making changes as almost everything is handled via anonymous arrays or hashes and it is important to be quite clear what value(s) you are affecting when making a change. In this context, an understanding of Read_History_With_TmpUpdate() and DefinePerlParsingFormat()… text/html 2009-01-03T19:16:28+01:00 http://datareign.co.uk/doku.php?id=awstats_variables&rev=1231010188&do=diff These entries specify the variables that are especially relevant when altering the behaviour of AWStats. Array that holds the values stripped from a line in the source log file. The elements in the array depend on the format supplied in the configuration file. Format code 4, results in the following index variables being set... text/html 2009-11-25T09:29:47+01:00 http://datareign.co.uk/doku.php?id=bash&rev=1259141387&do=diff Created as a replacement for the venerable Unix Bourne Shell, Bash is a flexible tool that supports a rich command set and a powerful command language. The file /etc/profile, if present, is read on start-up, followed by ~/.bash_profile. Some implementations may read ~/.profile if the other two files are NOT present but this behaviour cannot be relied on. text/html 2008-12-29T15:17:53+01:00 http://datareign.co.uk/doku.php?id=c&rev=1230563873&do=diff C is now one of the longest established languages still in general use. Much of its attraction stems from its simplicity and the attendant flexibility this confers. The other side of that coin is that C will happily permit the programmer to do anything, including trash the entire computer. For this reason, sound design and good programming practices are essential to produce maintainable code. text/html 2009-04-04T22:23:21+01:00 http://datareign.co.uk/doku.php?id=c_command_line_calculator&rev=1238880201&do=diff This is a useful little tool. It's a multi-function floating point calculator that can take the first part of its input from the environment, thus you can do something like: user_prompt> calc 349 / 3.45 | calc ^ 7 which will give the result... text/html 2009-04-05T09:38:35+01:00 http://datareign.co.uk/doku.php?id=c_date_arithmetic&rev=1238920715&do=diff I wrote this for a particular case where I needed to find out the number of seconds batch jobs had run for. The jobs produced logs which had the start and stop times in the format... CCYYMMDDhhmmss ...so at least the conversions were straightforward, as can be seen from the code. text/html 2009-01-03T19:16:29+01:00 http://datareign.co.uk/doku.php?id=c_ebcdic_ascii_code_converter&rev=1231010189&do=diff There's still a need to convert data stored in IBM's EBCDIC (Extended Binary-Coded Decimal Interchange Code) format to the more common ASCII (American Standard Code for Information Interchange). Occasionally it's necessary to do the opposite. This little filter converts in either direction. text/html 2009-01-03T19:16:29+01:00 http://datareign.co.uk/doku.php?id=c_file_date_reader&rev=1231010189&do=diff Here's a little programme that gets all the access dates associated with a Unix file. The first date (called 'access' here) is the date that the file was last opened, even for a read. The other two dates show the date the file was last written to and the date it had its status changed, respectively. text/html 2009-01-03T19:16:29+01:00 http://datareign.co.uk/doku.php?id=c_subdirectory_reader&rev=1231010189&do=diff This shows the sub-directories in the current path. It's not a lot different to something like... ls-l | grep ^d | cut xxx Where xxx is the position of the filename but unlike the shell code, it isn't subject to the vagaries of the ls command. /* --------------------------------------------- Name: sdr Purpose: Displays the directories subservient to the current directory. ------------------------------------------ */ #include <stdio.h> #include <dirent.h> #in… text/html 2010-02-06T10:37:40+01:00 http://datareign.co.uk/doku.php?id=codeblocks&rev=1265452660&do=diff Code::Blocks can be used for development with a wide range of languages and libraries. It's in constant development so check the project's site frequently text/html 2009-01-16T12:02:03+01:00 http://datareign.co.uk/doku.php?id=datastage&rev=1232107323&do=diff Datastage, originally sold as Ardent Datastage and now part of the IBM Websphere product group, is a relatively mature ETL tool. * Datastage Palettes A description of the components available for constructing jobs. * Datastage Processing Overview of what a Datastage job looks like and how it works. text/html 2009-01-16T11:50:07+01:00 http://datareign.co.uk/doku.php?id=datastage_job_sequences&rev=1232106607&do=diff Job sequences are created in just the same way as any other Datastage job, by dropping the icons for jobs onto the palette and linking them as appropriate. Many jobs require one task to be complete before the next can start. In such a case, you'll simply want them chained together in the right order. Of course, you'll want to define what needs to happen if things go wrong and, for that purpose, you'll need to define exception handling, typically by linking an Exception component to an Email … text/html 2009-01-14T17:12:46+01:00 http://datareign.co.uk/doku.php?id=datastage_palettes&rev=1231953166&do=diff The palettes contain component templates that are assembled to build a job. Components are simply dragged to the canvass and then linked to form the flow of the finished programme. * Annotation * Container * Description Annotation * Link specifies how data is moved within the job. The terminology is slightly confusing as an Input Link is used to send data into the target database while an Output Link corresponds to a Select statement and extracts data from the attached database. text/html 2009-01-15T10:40:14+01:00 http://datareign.co.uk/doku.php?id=datastage_processing&rev=1232016014&do=diff All Datastage processing may be considered as being a form of Extract, Transform & Load (ETL), although it is possible to develop other processes with the tool. Because Datastage jobs tend to be made up from a large number of sub-jobs, carefull planning beforehand is essential if the process is not to 'get away from' the implementors, with a confusion of roles and a profusion of competing and even conflictiong components. text/html 2010-05-11T15:50:58+01:00 http://datareign.co.uk/doku.php?id=dell_inspiron_1750&rev=1273589458&do=diff The Inspiron 1750 is a low cost but reasonably powerful laptop with an Intel 64 bit processor at its heart. The following tips may be of help to other users but please note that the Inspiron 1750 comes with three possible processors, three possible display circuits, three possible wireless networks and a variety of hard disk options. text/html 2009-01-11T14:38:27+01:00 http://datareign.co.uk/doku.php?id=dimensional_modelling&rev=1231684707&do=diff It used to be called 'normalisation' but, whatever the name, the game's the same: keeping data organised as efficiently as possible, while retaining speed of access and ease of maintenance. Let's take a common requirement: maintaining invoices. In the days before computers, the process was quite simple... text/html 2009-01-18T22:35:51+01:00 http://datareign.co.uk/doku.php?id=documentation&rev=1232318151&do=diff This page is aimed at working programmers in large organisations but much of it applies to anyone producing code that will be viewed by and maintained by programmers other than themselves. There is no excuse for poor documentation in any programme. All modern languages provide a mechanism for commenting and it should be used. What little extra effort it takes is more than amply repaid by the time saved in maintenance. It is possible to go further and state that any programmer who fails to provi… text/html 2009-02-01T11:41:24+01:00 http://datareign.co.uk/doku.php?id=dokuwiki&rev=1233488484&do=diff Dokuwiki is a wiki implementation that uses plain text files to store data, rather than a database management system. The most important benefit this provides, is that the entire wiki is easily duplicated and distributed. One example of where this would be an advantage: an organisation that, for security reasons, does not wish laptop users to access the Web from outside the company firewall but does require that those users have access to the company's knowledge base. Because the entire wiki … text/html 2009-01-18T15:27:11+01:00 http://datareign.co.uk/doku.php?id=dokuwiki_styles&rev=1232292431&do=diff A brief introduction to the files that control the the appearance of the output. Template authors vary as to how much information they provide towards editing the component files. All, or nearly all, templates will provide these basic files and you can do a lot of customisation without touching any others. text/html 2010-07-11T11:48:59+01:00 http://datareign.co.uk/doku.php?id=edup_wireless_lan_pcmcia_adapter&rev=1278845339&do=diff The EDUP PCMCIA WiFi card is commonly sold on eBay for an extremely attractive price that makes it ideal for resurrecting old hardware. Unfortunately, the software supplied with it (if any) does not appear to function. The card itself seems to come in more than one flavour. The commonest is Broadcom based, but there are, apparently, other chip sets in use. The one we acquired was a Broadcom version and what follows is predicated on that. text/html 2009-09-13T09:32:01+01:00 http://datareign.co.uk/doku.php?id=flvtool2&rev=1252830721&do=diff Flash has become the de facto standard for delivering video and other animated graphic material across the internet. There are many tools for working with flash and video but some are more useful than others. flvtool2 is an especially good example for high end use, particularly because it is command line driven and therefor appropriate for intensive use. You can visit its home page here. text/html 2010-05-22T09:33:18+01:00 http://datareign.co.uk/doku.php?id=freebsd&rev=1274517198&do=diff If you're looking for an open source operating system that isn't Linux, then FreeBSD may be the right choice. It's a long established project with a strong support group. text/html 2010-05-23T17:58:34+01:00 http://datareign.co.uk/doku.php?id=hardware&rev=1274633914&do=diff * Linksys NSLU2 Pocket sized network attached storage controller with many other uses. * Hardware Troubleshooting Tips * Palm Handheld Computers * Dell Inspiron 1750 * EDUP Wireless LAN PCMCIA Adapter text/html 2009-01-04T18:45:50+01:00 http://datareign.co.uk/doku.php?id=hardware_troubleshooting_tips&rev=1231094750&do=diff Modern computer equipment is remarkably reliable. When things do go wrong, they can often be solved by very simple procedures. Before calling out the service engineers, take the trouble to run through the procedures shown here. They may just save you both expense and embarrasment. text/html 2009-08-22T09:55:47+01:00 http://datareign.co.uk/doku.php?id=java&rev=1250931347&do=diff Java is now one of the most widely used languages across most, if not all, IT sectors. A major part of its attraction has to be that it is free. That's right, most implementations cost nothing! Yet it's supported by a major American corporation: Sun Systems. text/html 2009-01-14T15:36:23+01:00 http://datareign.co.uk/doku.php?id=joomla&rev=1231947383&do=diff Joomla is a fairly mature content management system, written in PHP and largely intended to work with Apache and MySQL. * Joomla Structure What's behind a Joomla website. * Joomla 1.5 Installation Some tips that may save you trouble. * Joomla first steps Some notes on how to get started. text/html 2009-01-02T14:16:40+01:00 http://datareign.co.uk/doku.php?id=joomla_1.5_installation&rev=1230905800&do=diff The Joomla installation process is pretty straightforward, using a script that will automatically fire off when you point your browser at the new site, but there are some points where things can go wrong. If you get a message saying that your PHP installation may be faulty or that you haven't allowed your browser to accept cookies, the problem may well be that your PHP session save path isn't correct. text/html 2009-01-09T18:21:20+01:00 http://datareign.co.uk/doku.php?id=joomla_first_steps&rev=1231525280&do=diff Once you have the sample site up (you did follow the advice to install the sample site, didn't you?) you can get the feel of how Joomla goes together by enabling and disabling components until you get something approximating what you want your site to look like. text/html 2009-01-20T21:23:02+01:00 http://datareign.co.uk/doku.php?id=joomla_index.php&rev=1232486582&do=diff index.php is the only file that Joomla insists is present in a template. It is where all the main logic of a template is stored and has to specify all the module and component display code. Although any JavaScript code would also be referenced here, it is probably a bad idea to include formatting and layout directives in this file. text/html 2009-01-13T11:32:54+01:00 http://datareign.co.uk/doku.php?id=joomla_migration_process&rev=1231846374&do=diff Once your Joomla based website is working the way you wish it to, you'll need to migrate it from your development server to your live server. Remember that a Joomla-based website consists of the Joomla files and templates plus the data stored in your RDBMS, which is usually MySql. text/html 2009-01-21T16:52:38+01:00 http://datareign.co.uk/doku.php?id=joomla_structure&rev=1232556758&do=diff Joomla is not a single application but an amalgamation of several technologies. This is, of course, true of much modern software. In Joomla, understanding the way in which the various technologies interact will be very helpfull in building and maintaining reliable websites. As the various components within Joomla interact with their underlying technologies, data passes back and forth. These data flows are what Joomla is mainly concerned with. text/html 2009-01-20T21:27:56+01:00 http://datareign.co.uk/doku.php?id=joomla_template.css&rev=1232486876&do=diff template.css holds the formatting information for a Joomla installation. Ideally, you would provide, in this one place, everything required to define your page layouts. Some, but not all, of the definitions in the .css file are... * font styles * font colours * positioning * template image definitions * column specifications * list formatting * etc., etc. text/html 2010-01-09T11:36:27+01:00 http://datareign.co.uk/doku.php?id=linksys_nslu2&rev=1263036987&do=diff The NSLU2, known affectionately as the Slug, is a cheap simple device that can do many things beside its original designed function as a NAS. * Unslung The simplest alternative to the Slug's default Linux installation. * thttpd A tiny web server, used for the Slug's default intranet interface. text/html 2009-01-31T09:40:03+01:00 http://datareign.co.uk/doku.php?id=math_for_programmers&rev=1233394803&do=diff At one time, there was a widely held belief that all programmers were mathematicians. Of course, we know that this ”ain't necessarily so”. However, some understanding of math is a valuable tool for any programmer. It is probably useful to define what we mean by the term “mathemetics”. Let's start with how Wikipedia defines it: text/html 2009-01-08T13:49:45+01:00 http://datareign.co.uk/doku.php?id=methodologies&rev=1231422585&do=diff * Documentation Some thoughts on commercial standards in software development. * Dimensional Modelling text/html 2009-04-14T10:42:54+01:00 http://datareign.co.uk/doku.php?id=microsoft_dos&rev=1239702174&do=diff Before there was Windows, there was MS-DOS, a command line operating system that inherited much from the first widely used microcomputer operating system: CP/M. DOS is still available under Windows but in a classic case of the tail wagging the dog, it now runs as a client service, hosted by the Windows kernel, instead of itself hosting Windows, as was the case originally. text/html 2010-05-12T09:22:55+01:00 http://datareign.co.uk/doku.php?id=microsoft_windows&rev=1273652575&do=diff There is so much information on Windows that more would seem superfluous. However, these are tips that aren't so easy to find when you need them in a hurry. Open the Control Panel; Double Click Scheduled Tasks; Double Click Add Scheduled Task; follow the Wizard through. All you need to remember is to click the When my computer starts radio button and to assign a user with the right privileges to run the task. text/html 2009-12-07T09:00:13+01:00 http://datareign.co.uk/doku.php?id=mysql&rev=1260176413&do=diff MySQL is currently the front runner in the open source relational database manager stakes. Some tips on how to install MySQL: * MySQL installation * MySQL root password * MySQL database creation * MySQL Adding a user * mysqldump * MySQL scripts * MySQL date handling text/html 2009-01-23T15:29:34+01:00 http://datareign.co.uk/doku.php?id=mysql_database_creation&rev=1232724574&do=diff Provided that the mysqld service is running, creating a database is simply a matter of logging in as a user with sufficient privileges... $> mysql -U root -P Enter password: xxxxxxxxxxxx mysql> create database customers; Query OK, 1 row affected (0.01 sec) Then create a database owner and give it full privileges: text/html 2009-12-07T09:21:11+01:00 http://datareign.co.uk/doku.php?id=mysql_date_handling&rev=1260177671&do=diff MySQL has some useful facilities for handling Unix style dates and times You can create Unix epoch dates on the fly and you can compare them with 'real' dates... select count(*) from watchdog where timestamp >= UNIX_TIMESTAMP('2009-11-01 00:00:00') and timestamp <= UNIX_TIMESTAMP('2009-11-31 23:59:59'); text/html 2009-10-19T14:25:16+01:00 http://datareign.co.uk/doku.php?id=mysql_installation&rev=1255958716&do=diff You can obtain MySQL from the download site. * Locate and select the appropriate package for your platform. * If prompted, specify a location on your system in which to download and install MySQL. * Browse to where you downloaded MySQL, and double-click the installer file. The MySQL Server Setup wizard guides you through the MySQL installation, followed by the Configuration wizard. text/html 2009-01-02T11:34:09+01:00 http://datareign.co.uk/doku.php?id=mysql_root_password&rev=1230896049&do=diff MySQL comes with the root user set up by default but without a password. Hence, with a brand new installation you can do this: Unix>mysql -u root Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1 Server version: 5.0.51b Source distribution Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql> Yep, you're into the database manager as the boss user without having to go through any security. As the root user can do anything he wis… text/html 2009-11-09T09:30:44+01:00 http://datareign.co.uk/doku.php?id=mysql_scripts&rev=1257759044&do=diff There are two basic ways to run MySQL scripts: Just pipe the script into your command line, as in... $> mysql -u root -p targetdatabase <scriptname.sql The components of this (simplified) line are: * -u introduces the user name. The user must have sufficient privileges for all the tables that the script addresses. * -p invokes a password prompt. If you want to invoke the session without having to enter a password (as in a 'cron' job) you can use the syntax --password=anystring, but t… text/html 2009-11-06T15:07:17+01:00 http://datareign.co.uk/doku.php?id=mysqldump&rev=1257520037&do=diff This is the replacement for saving and restoring databases or single tables. To save a single table... /Applications/XAMPP/xamppfiles/bin/mysqldump \ -u root -p \ --single-transaction SalesDatabase \ --tables SalesPeopleTable \ >/Data/GlobalData/Projects/Sales/SalesPeopleTable.sql We've broken this up into lines for clarity but you would probably enter it as a single line in most cases. text/html 2009-01-30T10:06:21+01:00 http://datareign.co.uk/doku.php?id=old_computers&rev=1233309981&do=diff There is a proverb, ancient in many cultures, which can be stated as: * “if you don't know where you came from, you cannot know where you are going”. The process, far from complete, that is the information revolution, has many roots and those of us who have lived through the second half of the twentieth century, have been privileged to witness an amazing transformation. text/html 2010-05-21T08:50:41+01:00 http://datareign.co.uk/doku.php?id=openssl&rev=1274428241&do=diff The first place to look for information is the OpenSSL project page. The following are some practical uses we've found for the program... Here are two scripts that use DES3 to encrypt and decrypt files. Note that you could easily change the encryption model simply by altering the call to openssl. text/html 2009-01-07T11:53:45+01:00 http://datareign.co.uk/doku.php?id=oracle&rev=1231329225&do=diff Oracle is a heavy duty system in every way, the full set of documentation for Oracle running to a complete dead tree and then some. Here are just some tips we've found useful. * Oracle SQL Plus The Swiss Army Knife. * Oracle Replication Keeping things synchronised. text/html 2009-01-07T11:54:34+01:00 http://datareign.co.uk/doku.php?id=oracle_replication&rev=1231329274&do=diff For the nuts and bolts of Oracle Replication, see the entry on PL/SQL Streams. text/html 2009-01-03T19:16:30+01:00 http://datareign.co.uk/doku.php?id=oracle_sql_plus&rev=1231010190&do=diff For a very long time, Oracle has shipped with the SQL*Plus application as standard. This provides command line access to the database engine, meaning that you can write Unix shell scripts or DOS batch files that can run unattended and without the overhead of communicating with a GUI front end application. text/html 2010-05-18T09:38:14+01:00 http://datareign.co.uk/doku.php?id=palm_handheld_computers&rev=1274171894&do=diff These are still, in my opinion, the most user friendly PDAs. In addition to Palm themselves, companies like Alphasmart and Sony have produced devices which use the Palm Operating System (also known as PalmOS). PalmOS provides an effective and well debugged process for storing an image of the PDA's memory on a host computer's disk. Called 'Hotsync', this stores all the basic data held in the PDA to a user directory on the host. text/html 2009-02-01T10:51:01+01:00 http://datareign.co.uk/doku.php?id=pdftotext&rev=1233485461&do=diff The pdftotext command is a very useful utility that reads a PDF file and dumps its contents to a text file. if you issue the command without arguments, you'll get a helpful synopsis... $> pdftotext pdftotext version 3.01 Copyright 1996-2005 Glyph & Cog, LLC Usage: pdftotext [options] <PDF-file> [<text-file>] -f <int> : first page to convert -l <int> : last page to convert -layout : maintain original physical layout -raw : keep strings… text/html 2009-04-13T10:18:22+01:00 http://datareign.co.uk/doku.php?id=perl&rev=1239614302&do=diff Created originally by Larry Wall, Perl is available for almost every operating system. It has evolved from a simple report scripting language to one of the most effective general purpose computer languages while still retaining the strengths of its scripting origins. text/html 2009-01-03T19:16:31+01:00 http://datareign.co.uk/doku.php?id=perl_and_external_processes&rev=1231010191&do=diff Under Unix, Perl plays very nicely with external processes. Suppose you want to run a process and retrieve its return value. All you need to do is something like... $Result = `ls *.sql` The problem is that this doesn't work at all on Windows so, if you want your programme to be fully portable, you need a workaround. My solution is to use the one common feature on both Windows and Unix, the redirection character (>). text/html 2009-04-13T12:32:22+01:00 http://datareign.co.uk/doku.php?id=perl_and_object_orientated_programming&rev=1239622342&do=diff Perl's approach to object oriented programming is evolutionary, rather than revolutionary. It makes use of existing keywords and paradigms to implement a simplistic form of object oriented programming, which, nevertheless, provides a usefull addition to the already large range of programming possibilities in the language. text/html 2009-03-23T16:44:36+01:00 http://datareign.co.uk/doku.php?id=perl_anomalies&rev=1237826676&do=diff These are issues that we have come across for which we can find no obvious solutions. We record them here in the hope that, if nothing else, others experiencing the same behaviour will, at least, be re-assured that they are not suffering alone. :-) This is not to say that these anomalies represent bugs in Perl, they may simply be straightforward failings on our part. If you can spot a solution, we'll be very grateful for your input! text/html 2009-04-04T22:14:54+01:00 http://datareign.co.uk/doku.php?id=perl_associative_arrays&rev=1238879694&do=diff Also known as 'hashes' or 'keyed arrays', associative arrays provide a way to link two pieces of data together in a simple yet surprisingly efective data structure. One piece of data, called the key is the index into the array. The second item, the value, is the data to be retrieved when the key is provided. text/html 2009-01-03T19:16:31+01:00 http://datareign.co.uk/doku.php?id=perl_dates_and_times&rev=1231010191&do=diff Dates in Perl are a pretty big subject but the essence can be reduced to two simple rules: use 'localtime' to retrieve Perl's internal date block and then use 'sprintf' to format the retrieved date. The following subroutine returns the current date and time in the format 'dd-MMM-yy hh:mm' (e.g. 23-DEC-05 15:35)... text/html 2009-03-24T14:15:16+01:00 http://datareign.co.uk/doku.php?id=perl_debugger&rev=1237904116&do=diff Perl's debugger sometimes seems like the language's best kept secret, yet it is the one tool that every programmer should use. The best place to start is the Perl debuuger page at perl.org. * c (Continue to). You specify either a line number or a named subroutine and the debugger will initiate the run, halting when the target is reached. This is one of the most usefull commands because Perl never throws away anything and especially not line numbers. Decide where things are going wrong, and… text/html 2009-01-23T15:27:10+01:00 http://datareign.co.uk/doku.php?id=perl_execution_tracing&rev=1232724430&do=diff Programmes run from the command line sometimes need to run silently and sometimes need to provide varying levels of of information. This simple sub-routine, plus a global variable, provides just one approach to achieving this end... sub TraceScript { my $P_REPORT_LEVEL = $_[0]; my $P_CALLER = sprintf("%25s", $_[1]); my $P_MESSAGE = $_[2]; my $V_CALL_ID = $P_CALLER . "==> "; my $V_COMMAND; # -------------------------------------------------- # If the pass… text/html 2009-02-27T18:03:27+01:00 http://datareign.co.uk/doku.php?id=perl_file_handling&rev=1235757807&do=diff You often want to know when a file was last modified, say, in order to decide if this version is newer than the version it's being compared with. Perl provides a very convenient stat() function that includes this, along with a variety of other information. text/html 2009-01-03T19:16:31+01:00 http://datareign.co.uk/doku.php?id=perl_help_file_display_subsystem&rev=1231010191&do=diff Perl can be used in GUIs with the appropriate libraries but it's far more often used from the command line. That being the case, a method of providing on-line help is a useful card to hide up your sleeve. The following two sub-routines (NextHelpSection and ShowHelp) are all that's required to provide a reasonably comprehensive online manual. Additions, such as a string search facility, I leave as an excercise for the reader. text/html 2009-01-03T19:16:31+01:00 http://datareign.co.uk/doku.php?id=perl_libraries_and_search_paths&rev=1231010191&do=diff Understanding Perl's include mechanism is a key to getting reliable results with little fuss. Perl, like all modern languages, has mechanisms for adding pre-written pieces of code into your scripts. Indeed, almost all of the standard Perl libraries are themselves scripts. These libraries are generally added to a script by way of the use and require commands... text/html 2009-01-03T19:16:31+01:00 http://datareign.co.uk/doku.php?id=perl_or_pipe_syntax&rev=1231010191&do=diff At first glance, the or operator seems to work the same as the || operator and, in many cases, it does. However, there is a hidden gotcha waiting to trap you. Consider the following piece of code... $result = 'a' || 'b' || 'c'; print "Result from \'||\' strings is $result \n"; $result = 'a' or 'b' or 'c'; print "Result from \'or\' strings is $result \n"; $result = 0 || 3 || 4 ; print"Result from \'||\' numbers is $result \n"; $result = 0 or 3 or 4 ; print"Result from \'or\' numbers is … text/html 2009-01-03T19:16:31+01:00 http://datareign.co.uk/doku.php?id=perl_progress_spinner&rev=1231010191&do=diff I always find 'silent' programmes especially irritating. There's nothing worse than starting a process and then watching a frozen screen in the hope of seeing some sign of progress. This is especially irritating with CLI programmes - you just don't know if it's busy, crashed or plain confused. text/html 2009-01-03T21:51:37+01:00 http://datareign.co.uk/doku.php?id=perl_regular_expressions&rev=1231019497&do=diff Regular expressions (often abreviated to regexes) are a huge subject. This page just deals with the ones that we have found useful. Basically, a regular expression looks like this: a/t/r/s where... * a is the operation to be performed * / is the delimiter * t is the target of the operation * r is the replacement value for the operation * s is the scope over which the operation is to be performed text/html 2009-01-03T19:16:32+01:00 http://datareign.co.uk/doku.php?id=perl_string_handling&rev=1231010192&do=diff split returns an array formed from the value but broken at each point where the subject of the regular expression appears. Say, for example, you wrote ... @Result = split(/:/, "apples:oranges:pears" then @Result would contain the elements apples oranges pears with the dividing ':' discarded. The following real example is for extracting the required item from a comma-delimited list, such as a line in a CSV file... text/html 2009-01-05T16:46:29+01:00 http://datareign.co.uk/doku.php?id=php&rev=1231173989&do=diff PHP has become the default language of the web. * PHP problems text/html 2009-01-05T16:47:42+01:00 http://datareign.co.uk/doku.php?id=php_problems&rev=1231174062&do=diff The session save path is one of the settings in the php.ini file. Faults with this setting can appear as a variety of symptoms, such as a complaint that the user's browser is blocking cookies, when it is not. The commonest fault is that the path is not defined: text/html 2009-01-05T16:45:23+01:00 http://datareign.co.uk/doku.php?id=php_session_save_path&rev=1231173923&do=diff text/html 2009-01-07T11:51:06+01:00 http://datareign.co.uk/doku.php?id=pl_sql&rev=1231329066&do=diff * PL/SQL Procedure Overview * PL/SQL Decode a different approach to 'case' functionality. * PL/SQL Merge Inserts and updates in one neat package. * PL/SQL Streams text/html 2009-01-07T11:46:57+01:00 http://datareign.co.uk/doku.php?id=pl_sql_decode&rev=1231328817&do=diff At first blush, PL/SQL appears to lack anything remotely like a case statement, so that the only way to make complex decisions is by means of ugly chains of if statements. In fact though, Oracle has an extremely powerfull equivalent of the case statement which has the additional advantage of being available for use in standard queries. text/html 2009-01-07T11:49:59+01:00 http://datareign.co.uk/doku.php?id=pl_sql_merge&rev=1231328999&do=diff New in Oracle's 9i release was the PL/SQL merge command which has a syntax rather like this... MERGE INTO TargetTable T USING SourceTable S ON (S.Column1 = T.Column2 AND S.Column3 = T.Column4) WHEN MATCHED THEN UPDATE SET T.Column5 = S.Column6, T.Column7 = S.Column8 WHEN NOT MATCHED THEN INSERT (T.Column9, T.Column10) VALUES (S.Column11, S.Column12) This is much nicer t… text/html 2009-01-07T11:42:06+01:00 http://datareign.co.uk/doku.php?id=pl_sql_procedure_overview&rev=1231328526&do=diff PL/SQL has many endearing features for the programmer and one or two which are less so. One of its nicer features is the ability to define procedures, which can then be used as if they were a part of the language. Procedures may define and use variables that are local to the procedure. text/html 2009-01-07T18:17:33+01:00 http://datareign.co.uk/doku.php?id=pl_sql_streams&rev=1231352253&do=diff Oracle's PL/SQL streams toolset is a powerfull database replication tool, which allows you to synchronise multiple databases or sites selectively or 'en masse'. Streams deal with events and you can imagine them as a set of three processes... * Capture records an event, typically an insertion into, update of or deletion from a table. text/html 2009-01-14T11:48:50+01:00 http://datareign.co.uk/doku.php?id=python&rev=1231933730&do=diff The best place to start is with the Python web site. This offers considerable documentation and help, although it can be a little daunting until you start to find your way around. Python was strongly influenced by the ABC teaching language and also includes elements of C, Lisp and the Bourne shell. text/html 2010-05-21T08:30:06+01:00 http://datareign.co.uk/doku.php?id=software&rev=1274427006&do=diff Some of the software that we've used over the last 25+ years. The information here is based on our own experience in a wide variety of industries and on a very large range of platforms. It's very important to keep in mind that, not only does software evolve very rapidly but differences in platforms can affect its use. text/html 2009-03-03T09:42:42+01:00 http://datareign.co.uk/doku.php?id=sql_server_backups&rev=1236073362&do=diff The following information applies to SQL Server 2005, some of this may be invalid for later versions. * Expand the Object Explorer Tree View to show the database you wish to back up. * Right click on the database heading and select Tasks|Back up... * Make sure that the Database: entry is for your selected database and the Backup Type: is Full. * The Radio button for Backup component: | Database must be selected. * Fill in the Name: and Description fields as required. * By default… text/html 2009-03-03T09:12:46+01:00 http://datareign.co.uk/doku.php?id=sql_server_microsoft&rev=1236071566&do=diff Microsoft's SQL Server product is a fork of Sybase. As a result, much of what you can find on the Sybase pages is directly applicable to MS-SQL. There are differences, however. MS-SQL has several functions not found in Sybase and is, understandably, aimed entirely at the Microsoft Windows environment, unlike Sybase, which is available on Linux, Windows and various flavours of Unix. text/html 2010-03-10T09:55:35+01:00 http://datareign.co.uk/doku.php?id=start&rev=1268214935&do=diff First, an apology: * This is always going to be a work in progress and some pages you look at may have an “unfinished” feel to them. Often, such pages are placeholders, to remind us that we need to add that information, and we only have a limited amount of time to work on them. Please bear with us on this! text/html 2009-02-01T11:32:28+01:00 http://datareign.co.uk/doku.php?id=subversion&rev=1233487948&do=diff Subversion is a powerful, open source and cross platform version control system that supports all file formats and is rapidly gaining acceptance in the commercial sector, in addition to the open source community. There's a useful overview on Wikipedia, which is worth reading before diving in, especially if you're new to version control systems. text/html 2009-01-07T11:22:43+01:00 http://datareign.co.uk/doku.php?id=sybase&rev=1231327363&do=diff Sybase introduced the first client/server online relational database product in 1987. In the 'nineties, it spawned SQL Server, Microsoft's RDBM, which still retains strong similarities to the parent product, although the technologies have diverged somewhat. text/html 2009-01-03T19:16:32+01:00 http://datareign.co.uk/doku.php?id=sybase_ase_user_settings&rev=1231010192&do=diff On a Unix or Linux machine, each user will need some shell variables set up and their path variable extended to access Sybase easily. These values are set up in the user's shell start script. For Korn shell this is '.profile' and for Bash it is '.bashrc'. text/html 2009-01-01T17:59:55+01:00 http://datareign.co.uk/doku.php?id=sybase_central&rev=1230832795&do=diff Sybase Central is the utility for managing Sybase servers. It's a graphical interface written in Java so you need to make sure your Java runtime is installed and ready to use. Start by logging in as the sybase user... $ su - sybase Password: xxxxx and then run scjview (usually found in /opt/sybase/sybcent41/bin (where 41 is the version number). This should bring up the main Sybase Central window... text/html 2009-01-03T19:16:33+01:00 http://datareign.co.uk/doku.php?id=sybase_installation_issues&rev=1231010193&do=diff Sybase can be installed on Unix, Linux, Apple OS-X and Windows NT/2000/XP. Like Oracle, Sybase makes a development/evaluation version available free of charge for many platforms. Do a web search for '<OS> sybase download' to find a version suitable for your needs. text/html 2009-01-03T19:16:33+01:00 http://datareign.co.uk/doku.php?id=sybase_start_and_stop&rev=1231010193&do=diff The default installations of Sybase don't do anything about including entries in the start script directories, so you need to start the servers yourself. One way of running servers is to log in as the sybase user and just start the servers from the /opt/sybase/ASE-12_5/install directory. In this directory, you'll find the following scripts... text/html 2009-01-07T11:35:08+01:00 http://datareign.co.uk/doku.php?id=t-sql&rev=1231328108&do=diff * T-SQL Language Overview - Brief introduction to the Transactional Structured Query Language. * T-SQL Joins - Putting things together. * T-SQL String Manipulation - wiring up text. * T-SQL Date Manipulation - Calendar working. * T-SQL Aggregates - summing things up. text/html 2009-01-07T11:30:31+01:00 http://datareign.co.uk/doku.php?id=t-sql_aggregates&rev=1231327831&do=diff Unlike many dialects of SQL, Transact SQL allows you to reference columns which are NOT part of a Group By clause in an aggregate query. Thus the following is permissable... select salesman, office, avg(invoice) from turnover group by salesman which might produce something like... text/html 2009-01-07T11:34:26+01:00 http://datareign.co.uk/doku.php?id=t-sql_batch_segmentor&rev=1231328066&do=diff When running very large queries, particularly updates or deletions, it is helpfull to give feedback on the status of the process. One way of doing this is to run the query within a while loop and set ROWCOUNT to control the number of rows processed on each pass. text/html 2009-01-07T11:31:58+01:00 http://datareign.co.uk/doku.php?id=t-sql_compute_clauses&rev=1231327918&do=diff T-SQL possesses one extension which is marvellous when you need a sub-totalled report in a hurry. Look at this... select salesman, office, invoice from turnover order by salesman compute sum(invoice), avg(invoice) by salesman which produces something like... text/html 2009-01-07T11:36:31+01:00 http://datareign.co.uk/doku.php?id=t-sql_cursors&rev=1231328191&do=diff T-SQL is a set based language. This is excellent for many things but sometimes you want to step through a table processing one row at a time. An example would be if you were updating two or more tables, conditionally, from a single table. It might be possible to come up with acceptable set queries to perform the task but doing it in a linear manner gives far more control, albeit at the cost of greater processing time for the job. text/html 2009-01-07T11:27:41+01:00 http://datareign.co.uk/doku.php?id=t-sql_date_manipulation&rev=1231327661&do=diff Sybase provides the following built in date functions... * getdate() * datename(Part, Date) * datepart(RequiredPart, Date) * datediff(PartToCompare, FirstDate, SecondDate) * dateadd(PartToAdd, NumberOfParts, Date) You can use these functions anywhere BUT if you use them in a WHERE clause you'll generally force a table scan. Much better to store the result of a manipulation if you'll need to search on it regularly. text/html 2009-01-07T11:19:56+01:00 http://datareign.co.uk/doku.php?id=t-sql_joins&rev=1231327196&do=diff In SQL, a join is how you connect two or more tables to create a single result. You should be aware that T-SQL join syntax is slightly different for Oracle's PL/SQL syntax, which can be a source of frustration when you are using both at the same time. text/html 2009-01-07T11:24:34+01:00 http://datareign.co.uk/doku.php?id=t-sql_language_overview&rev=1231327474&do=diff Transact SQL is a very neat language which provides a simple and elegant way of splitting jobs into maneagable chunks (batching), local variable declaration and simple but effective programme control constructs. So far as Sybase is concerned, anything that preceeds the word 'go' in a script is part of the same batch. If there is anything wrong in any part of the batch, the whole thing is rejected and no changes take place on the server. text/html 2009-01-07T11:26:36+01:00 http://datareign.co.uk/doku.php?id=t-sql_string_manipulation&rev=1231327596&do=diff Sybase provides the following built in string functions... * datalength(String) * substring(String, Start, Length) * right(String, Length) * upper(String) * lower(String) * space(Length) * replicate(Character, Count) * stuff(String, Start, Length, ReplacementString) * reverse(String) * ltrim(String) * rtrim(String) * ascii(Character) * char(ASCII Code) * str(Number [, Length [, Decimals]]) * soundex(String) * difference(String1, String2) * charindex(StringToFi… text/html 2009-02-10T16:20:58+01:00 http://datareign.co.uk/doku.php?id=talend&rev=1234282858&do=diff Talend Open Studio is one of a new breed of ETLs being made available under the GPL open source licence. You can purchase support, making the experience very much more like using a commercial product. On the whole, Talend is as useable and as useful as most commercial ETLs, with the advantage that you can maintain and extend it yourself, if you wish. text/html 2009-09-13T09:35:54+01:00 http://datareign.co.uk/doku.php?id=talend_and_odbc&rev=1252830954&do=diff Talend will work with ODBC but it isn't entirely obvious how to set this up. The following notes may help. Don't forget, you must have a valid ODBC driver installed before you can connect to it. Most drivers are installed as part of the client software for a datasource, so look there first. text/html 2009-02-10T16:17:08+01:00 http://datareign.co.uk/doku.php?id=talend_debuggery&rev=1234282628&do=diff Before deployment, you should test your code thoroughly from within the Talend Workbench, which offers some very powerful tools for removing problems from your programmes. When you run a job from the Run tab of the control panel, any errors are directed to the panel's display. With Perl code, the error line numbers will fit neatly with the contents of the Code tab of the job editor. Just find the offending line and look for the problem. text/html 2009-02-10T16:56:01+01:00 http://datareign.co.uk/doku.php?id=talend_gotchas&rev=1234284961&do=diff Like all software, Talend is a work in progress and it reflects the tastes and decisions of its authors. These aren't always to everyone's liking but, as Talend is an Open Source project, you can always change anything that you really can't live with. text/html 2009-01-28T09:54:55+01:00 http://datareign.co.uk/doku.php?id=thttpd&rev=1233136495&do=diff thttpd is a lightweight alternative to Apache, very useful if you wish to run a web server on slower computers such as the Linksys NSLU2 (aka “the Slug”) thttpd generates a log that shows every request it receives. Using the default Unslung / ipkg installation for thttpd, the log will be generated as /opt/var/log/thttpd.log. In the time honoured Unix tradition, the way to view this as a live report is simply to run... text/html 2010-05-22T09:25:08+01:00 http://datareign.co.uk/doku.php?id=unix_and_linux&rev=1274516708&do=diff Information on the world's most common server operating system and, every day, more used on the desktop as well. * Unslung Minimal space Linux for use with the Linksys NLSU2 * FreeBSD Low footprint high performance alternative to Linux * Bash the 'B'ourne 'a'gain 'sh'ell. text/html 2009-12-07T09:20:03+01:00 http://datareign.co.uk/doku.php?id=unix_epoch_dates&rev=1260177603&do=diff Unix has a simple way to treat dates as ordered lists, by referring to them as the number of seconds since a fixed point in time. The fixed point is '00:00:00 1970-01-01 UTC' (with an epoch of '0') and dates after this are represented by positive numbers while dates prior to this are held as negative numbers. You can find a lot more about this on this Wikipedia page. text/html 2009-01-17T13:49:59+01:00 http://datareign.co.uk/doku.php?id=unslung&rev=1232200199&do=diff Unslung Linux is one of several implementations on the NLSU2 and the one closest to the Linux supplied in firmware. DokuWiki on Unslung If you install Dokuwiki on an Unslung NSLU2 using the ipkg command, you may not see the install.php file through your browser. This is because ipkg installs to /opt/share/www/dokuwiki/install.php and it's pretty unlikely that your browser is looking there. text/html 2009-01-04T18:47:58+01:00 http://datareign.co.uk/doku.php?id=vi&rev=1231094878&do=diff Tips and tricks for using vi. Note that most people these days use Vim which comes in both command line and graphical flavours. You can find a lot more information on the Vim tips wiki. There are a number of names and locations for this file. The safest way to find out where your particular installation expects to find it is to issue the command ”:version” during a vi session. You'll see a fair amount of useful data but in this case you're looking for lines like: text/html 2010-05-12T09:44:43+01:00 http://datareign.co.uk/doku.php?id=vmware&rev=1273653883&do=diff VMware is an Intel-only virtual machine manager. It provides relatively good performance by using a 'pass through' scheme, which executes guest code directly on the host. This avoids the performance hit suffered by VMMs that use emulation techniques to enable cross-platform virtualisation, such as running Intel guests on PowerPC hosts. text/html 2009-09-19T11:37:16+01:00 http://datareign.co.uk/doku.php?id=web_analytics&rev=1253356636&do=diff The analysis of web traffic is now a major requirement for organisations who use the internet to promote their products and/or deliver their services. It's still a relatively new field and products appear daily. * AWStats Web server event reporting tool. text/html 2009-09-13T09:20:10+01:00 http://datareign.co.uk/doku.php?id=web_publishing&rev=1252830010&do=diff Web publishing is no longer a black art performed by wizards in the depths of the night. Anyone can author web pages and now the art is to choose the tool that's best for your needs from a bewildering variety. * Dokuwiki Simple content management system using a text file back end. text/html 2009-09-19T11:55:06+01:00 http://datareign.co.uk/doku.php?id=wireshark&rev=1253357706&do=diff The project's home page is, of course, the best place to start. For use on a Mac, you can start by looking at Bernard Ehler's installation page. text/html 2010-02-06T10:49:04+01:00 http://datareign.co.uk/doku.php?id=wxformbuilder&rev=1265453344&do=diff wxFormBuilder is still evolving and it's worth paying regular visits to the project's home page. As of February 2010, the project recommends that the generated code should not be edited to add functionality outside of wxFormBuilder, as the generated code is replaced at each pass. Instead, the form builder's “generate inherited class” functionality should be used. text/html 2009-01-23T15:22:56+01:00 http://datareign.co.uk/doku.php?id=wxperl&rev=1232724176&do=diff This brings together Perl and wxWindows, the cross-platform GUI development library. The result is that you can programme sophisticated and responsive GUI applications that will run with little or no modification across Windows, Apple OS-X and Linux. text/html 2008-12-31T11:17:02+01:00 http://datareign.co.uk/doku.php?id=wxperl_setup_on_windows&rev=1230722222&do=diff (Before doing this, you MUST have done the wxPerl ActiveState Installation on Windows). You can download the latest version of the wxPerl package from the [<http://wxperl.sourceforge.net/download.html> project's home site]. The folowing is the correct way to install wxPerl on Windows (based on having spent some time using the incorrect method!)... text/html 2010-02-06T10:35:15+01:00 http://datareign.co.uk/doku.php?id=wxwidgets&rev=1265452515&do=diff wxWidgets, originally known as wxWindows, is a mature, open source system for building cross platform GUI applications. * wxFormBuilder is a cross platform visual windows builder for wxWidgets. * CodeBlocks is a cross-platform, multi language, graphical IDE that is especially good for wxWidgets development.