A/V Geeks Live Stream

transmitted that computer and it comes back laid out for us with four orders which we've placed on that supplier or four high voltage cable all on the same order as it happens but there's four items there but the where clauses can become quite complex because usually whether you've got a database that's got 20 30 50 thousands items on it it's no good just restricting yourself to a single supplier you very likely want to restrict yourself to some particular range of dates list me all the informations where supplier is more than two weeks late on delivery now I'm specifying the dates and things like this it gives you a where clause that perhaps takes a couple of lines far too messy to type in generally so in fact we save whole procedures and we can simply call up a procedure and list some parameters which we require can do this call is the keyword that brings in the cedar cedar I have here is rather peculiar names suit our users as it happens call it's listing items q4x works delivering ticket appeared so we have we got in the call to the procedure got a couple of dates contact number and an area number transmitted there you'll see that the it lists back to us the exactly inquiry that it's actually submitted where you'll see that we've got a format f3 and then a fairly complex where clause so that's qlp a mixture of command words list where etc data names from the sub skimmer and value is used for selection put together they're a simple but powerful facility for interrogating their database but how do users see it John Wilkinson sees it as just another way of using a database on the project size of sullivo there's so much data produced that the nor my normal manual methods it will be almost impossible to check it all out because you would have to check one person schedule against another person schedule and using QoP in fact or any computer database there were one is feeding that data in you therefore are carrying out a checking procedure having gone through that basis you then also have a single project record rather than many different manual schedules which although slightly different are basically using the same information as far as the computer is concerned you have a single record which anybody can look at at any point in time John Bernard sees it as a way of saving time by using qlp on our solemn vow project we were able to get a database system running very quickly indeed we used our application programmers to write the programs which maintain the database and qlp is used for the reporting side Jeff Jones sees it as a way of improving productivity well the main thing about qlp is it's very much quicker to write you can have an applications program might take you know two three days to write it's got very large procedure division and particularly for COBOL very large data division just defining the data in qlp you don't have any of this bother you obviously got less flexibility but you can perhaps only have a couple of lines of qlp to produce really quite complex reports it sounds too good to be true but there must be a compromise somewhere how do you pay for the benefits of qrp request to use an acquire language on a database you have got to provide ways into the database which might not be necessary if you're just using ordinary COBOL programs where the effect of having to provide extra entry points and number of other bits of data which you have to provide the costs of using the query language will often appear not the query language user in his query session but probably in the update programs and in costs of mass storage these additional entry points require storage on the database and particularly they require pointers down at fairly low levels of the database where there are very large numbers of records and of course the update programs have to put in all these links to these extra entry points and this is obviously going to mean more time for the updates but that's not the only price to pay the one two problems related to the way you hold data on the database and the designer has got to get useful sort of fact that he can't do things like compacting data people perhaps get into the habit of saying well we can save a lot of space on dates instead of storing them say the number of days of the 1st of January 1900 this save space on a database but it's absolutely useless if you look at this on a screen see some gobbledygook number doesn't mean anything user friendly form but it's not in London offices that qlp makes its biggest impact it's on site under pressure where information is crucial how does PRP solve next problem if somebody in the field wants to know when a Pacific is a specific piece of equipment I a pump or a vessel or a PA U is being delivered I can punch in a predetermined question a predefined question and hopefully that will give me the correct answer the computer helps us to locate whatever is missing it gives us an idea of whether it's been delivered to site or whether it's still lying in the yard in Scotland or whether in fact anybody else would remember to order it or not the main problems with using of VDU on site here it's a problem of communication with London the gpo system up here leans a lot to be designed especially in this locale we tend to lose the loggers a lot the calls are interrupted the cause the line disconnects crossed lines occur and it can tend to make life extremely frustrating especially when you're halfway through a printer the thing you have to recognize with a query language is that you're putting your database and facilities of the database into the hands of people who are not experienced DP users and who often won't understand the way the database works and perhaps even the problems that are associated with using the database and they could if you don't if you're not careful about the way you structure your sub schema start making inquiries which could go chasing all around all 30,000 records on the database with you know disastrous effects on the machine resources and on their own accounting costs and so in fact we have to design sub schemas that provide them with paths which don't allow them to do this sort of thing and the designer of the database in fact has to spend a lot of time setting the database up just so that the user can't do this sort of thing what matters to cjb is building this process plant the computer has to serve that end not restricted COBOL programming is used when requirements are known in advance but here in Shetland you can't plan everything and that is where qlp has a role to play you all right so that's testing out the the Syntel film scanner which I don't know maybe I'll try to show it to you here yeah [Music] so this allows me to scan film that is more damaged and has also icons 35-millimeter which is kind of great and do- and do a lot of other stuff there's there's some compromises that are taking place but [Music] anyways um so here's a way to bounce things up a little bit and so I'll be screening tomorrow around 8 o'clock so we'll see you then I just let you watch it rewind about that