what would a database system look like if it were NOT relational

problems
1) a lot of repeated data
2) inconsistent data

related tables

CustID on the Customer Table is a primary key
uniquely identifies a record

OrderID on the Orders Table is a primary key
uniquely identifies a record

benefits of a relational database:
1) smaller database, no repeated data
2) consistent data

BillCustId and ShipCustID are foreign keys
match up with primary key of another table

Indexing
What if I have 1 million records and I want to search for "Josh Waxman" as the name? How long will it take, on average, to find that record?

Why will it take 5 minutes? Sequential search.
(n+1)*(n/2)
(n^2 +n)/2
divide by n to get average
(n+1)/2 is the average

with 1 million records, sequential search will take (n+1)/2, or 500,000 time units, on average

within the CS department, there is a course called Analysis of Algorithms. Algorithm: a recipe for solving a problem.

Binary search would be much faster. But needs items to be in sorted order.

It is like the high-low game.
mid = (top + bottom)/2
if num looking for is more:
  top = mid + 1

if num looking for is less:
  bottom = mid - 1

we can either have a sorted list Or we can have Binary Search Tree. Course in CS dept called Data Structures. considers how to store collections of data.

if indexed, instead of O(n), it will take O(log n), or 20 searches for a million records.

we are skipping ch 1 hands on 2. we are on page 581, ch 1 hands on 3.

Quiz next time we meet; also Excel exam

The quiz on Ch4 in lecture book.
from SUNDAY, OCTOBER 23, 2011 until
SUNDAY, NOVEMBER 13, 2011

Read, do quickchecks of Ch 6

lecture

Goal Seek
within the PMT function

I can fiddle with some numbers

Solver -- more advanced -- goal seek on steroids

Solver can fiddle with multiple cells
Solver can solve for a maximum or minimum
Solver can work within constraints

Pivot Table
Pivot Chart

CSV file = comma separated value

difference between raw data and information
PivotTables and PivtoChartsCharts are more dynamic than Subtotal

Filtering and Advanced Filtering

in advanced filtering, within same row, it means AND
within diff rows, means OR

Financial Formulas

1) What function should I use?
FV, PV, PMT, RATE, NPER

2) Once I determine that, what should be the parameters

Wildcards:
*
?

J*sh
______
Josh
Jish
Jash
Joosh
Jsh

but not
Joshua

What about J?sh
____
Josh
Jish
Jash
Not Joosh
Not Jsh


Microsoft Access requires an actual file to work against. diff from word and excel

Many changes to your Access file cannot be undone.
Many changed to your Access file are automatically saved.

RDBS - relational database system
store your data, has ways of processing, viewing, asking questions about your data

Database: collection of Tables
Table: collection of records
Record: collection of fields
Field: one unit of information

Web Page Assignment

The web page assignment is due the day of the final exam.


But, all the files and directories making up your web pages assignment must end up in the public_html directory of your UNIX account. The filename of your main web page must be called index.html and located directly in the public_html directory of your UNIX account. Your web page assignment has to have at least the following:

• Pictures - Create a directory called pictures in your public_html directory. Don't forget to set the proper permissions for the pictures directory. Place all of the image files (pictures) you are using in all of your web pages in the pictures directory.
• About me - Create a web page (html file), in your public_html directory, describing yourself. Include a "photo", real or imagined, of yourself on this web page. Create a link to this web page in your main web page (index.html).
• My family - Create a web page (html file), in your public_html directory, describing your family. You can link to their web pages from there or include scanned pictures if you like! Create a link to this web page in your main web page (index.html). This web page should use CSS, referring to the external style sheet.
• My friends - Create a web page (html file), in your public_html directory, describing your friends. You can link to their web pages from there or include scanned pictures if you like! Create a link to this web page in your main web page (index.html). This web page should use CSS, referring to the external style sheet.
• My hobbies - Create a directory called hobbies in your public_html directory. Don't forget to set the proper permissions for the hobbies directory. Create a web page (html file), in the hobbies directory, that describes your hobby. Provide links to at least 2 web sites that deal with your hobby and you can put pictures there too. Create a link to this web page in your main web page (index.html).
• Queens College - Create a link to the college's main web page in your main web page (index.html).

Be Creative!!!

Experiment!!!

Make it look nice!!!

Practice Excel Exam 1.
Practice Excel Exam 2.
Practice Excel Exam 3.
Practice Excel Exam 4.
Practice Excel Exam 5.
Excel Review Presentation.


Download for Excel practice examsExam 1

HW:
Read through Ch 6, do the quickchecks


What needs to be done:
better review of financial functions
Goal Seek
Solver
Pivot Tables

HW: Do practice exercises for this chapter (excel ch 3 and 4)