Pages 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 16938 result(s) returned

Conclusion

Relational database systems underpin the majority of the managed data storage in computer systems. In this course we have considered database development as an instance of the waterfall model of the software development life cycle. We have seen that the same activities are required to develop and maintain databases that meet user requirements.


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1.6.4 Supporting data management strategies

Most of the development we've covered so far in this course has focused on meeting specific user requirements – that is, ensuring the right data are constrained correctly and made available to the right user processes. However, other questions must also be addressed in order to support a data management strategy: How frequently should data be backed-up? What auditing mechanisms are required? Which users will be permitted to perform which functions? Which database tools and user processes w
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1.6.3 Supporting users and user processes

Use of a database involves user processes (either application programs or database tools) which must be developed outside of the database development. In terms of the three-schema architecture we now need to address the development of the external schema. This will define the data accessible to each user process or group of user processes. In reality, most DBMSs, and SQL itself, do not have many facilities to support the explicit definition of the external schema. However, by using built-in q
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1.6.2 Populating the database

After a database has been created, there are two ways of populating the tables – either from existing data, or through the use of the user applications developed for the database.

For some tables, there may be existing data from another database or data files. For example, in establishing a database for a hospital you would expect that there are already some records of all the staff that have to be included in the database. Data might also be bought in from an outside agency (address
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1.4 Analysis

Data analysis begins with the statement of data requirements and then produces a conceptual data model. The aim of analysis is to obtain a detailed description of the data that will suit user requirements so that both high and low level properties of data and their use are dealt with. These include properties such as the possible range of values that can be permitted for attributes such as, in the Open University example for instance, the course code, course title and credit points.
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1.3 Requirements gathering

Here we are concerned only with the requirements that relate specifically to the data. Establishing requirements involves consultation with, and agreement among, all the users as to what persistent data they want to store along with an agreement as to the meaning and interpretation of the data elements. The data administrator plays a key role in this process as they overview the business, legal and ethical issues within the organisation that impact on the data requirements.

The data req
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6.2.2 Database servers

To be able to search a website like Lakeland's requires not only a web server but a database server. Like a web server, a database server is a computer that responds to requests from other computers. Its task is to find and extract data from a database.

The web and database servers form part of a distributed system. This means that separate computers exchange data and information across a network (in this case the internet) to produce results for a user. For
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5.2.1 Transforming the natural to the designed

The artist Christine Martell lives in Oregon in the United States and works with beads and visual images. I asked her to describe how she makes use of a computer to create her visual images of flowers and trees. She writes of her work:

I start by finding flowers that are compelling in some way, most often in form and colour. I take photographs with a 35 mm camera having a macro lens.

I'm usually looking for a
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5.1.2 The human genome

All life is ‘encoded’ chemically in genes. What this means is that the structure of an organism, the organs it possesses, its colouring, and so on are all determined by different genes. A very simple organism may have just a few genes, and a complex one tens of thousands. The ‘map’ of an organism's genes is referred to as its genome. It shows, in essence, which genes give rise to which characteristics or traits of the organism. The word ‘template’ would describe the
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5.1.1 What is DNA?

DNA (deoxyribonucleic acid) is frequently in the news for four main reasons.

  1. DNA can be used in crime detection to eliminate innocent suspects from enquiries or, conversely, to identify with a very high degree of probability the guilty.

  2. DNA is now used in medicine to detect the possibility that diseases having a genetic origin may occur in an individual. This enables doctors to prescribe preventative treatments.

  3. It is hope
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4.1.2 Geographical data

Modern maps are now mostly assembled by computers using very large collections of geographical data, such as latitude, longitude, altitude, roads and towns. Collections of data like this (stored in databases) aim to eliminate the need to duplicate data. The data in databases is described in symbols that the computer can handle, i.e. numbers. Even the names of features are symbolised using numbers.

If I were trying to tell you the way to a particular street in a town, using only t
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Sharing power and transforming educational practice
This free course, Sharing power and transforming educational practice, explores the notion of a life of learning and interrogates 'common-sense' assumptions about schooling. It considers what is the research process and how becoming a co-researcher with the people with whom you work can transform your expectations and practice.Author(s): Creator not set

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Except for third party materials and otherwise stated (see http://www.open.ac.uk/conditions terms and conditions), this content is made available under a http://creativecommons.org/licenses/by-nc-sa/2

Learning to teach: Making sense of learning to teach
This free course, Making sense of learning to teach, is the first of four courses which comprise the course Learning to teach. It draws on what we know about how people learn to become teachers. It explores the different approaches to teacher education and the different routes into teaching. It will help you to understand the philosophical and practical differences between the different approaches. It draws on research about students' experiences of learning to teach and considers the implicatio
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Learning to learn: Learning can mean change
This free course, Learning to learn: Learning can mean change, starts to explore what it takes to learn and change. Through the use of activities and introducing academic skills and evaluating websites, it will give you the opportunity to start to think about what change and learning means to you. First published on Tue, 29 Mar 2016 as Author(s): Creator not set

Acknowledgements

The content acknowledged below is Proprietary (see terms and conditions) and is used under licence.

Course image: woodleywonderworks in Flickr made available under Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence.

All materials included in th
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7 Logarithms

The equation 23 = 8 means that 3 is the index of the power to which we raise the number 2 to produce 8.

A logarithm is an index, and in this example, 3 is the logarithm of 8 to the base 2. We write this as

Log2 8 = 3

These two equations are identical: 23 = 8 and log2 8 = 3

They express the same fact in the language of logarithms.


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4.1.1 Getting off to a good start

You may find it useful to plan the way you will start your exam. Having a routine can be calming when under pressure. This is from a student who recommends a checklist:

I have a mental checklist of what I need to do once I've turned over the paper. I do this because I used to rush in and answer the fir
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3.1.1 First find a place to revise

Other than the obvious suggestions of having a warm, well-lit and comfortable place to work, we also suggest that you think about choosing a revision place where you can spread out your materials and leave them as they are, without having to pack anything away. This means that you can pick up and put down your revision whenever you find time to revise. This will help you to make the most of your revision time.

On the other hand, you may find that you concentrate better away from the dis
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7.3 Review the whole process

Before you file away your assignment and return to your current study, spend a little time reviewing the whole process of preparing, exploring, implementing and reviewing your assignment. Review what you did and how you did it in each of the four phases. Trying to identify just one thing that went well and one thing that you could have done differently can help you in your future study. Remember that your review should focus on the process of the preparation
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4.1 Preparing

In the preparation phase you should pause before starting a new section of work and think about it as a whole. What needs to be covered? What are the various components of this block of work? What are the learning objectives or outcomes? What will you need to know and be able to do at the end of it? What is required in the assignment?

There are two main activities during this phase, both directly related to your course work and assignment:

  • analysing
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