Archive for March, 2010
Meet the ISO
Posted by: | CommentsOur pdCountry database product includes information derived from ISO – International Organization for Standardization – standards and publications. We though you would like to know more about the organization, so meet the ISO:
Founded February 23, 1947, the ISO is a network of the national standards institutes of 159 countries, with one member per country. Its Central Secretariat, which coordinates the system, is headquartered in Geneva, Switzerland, and English and French serve as the official languages.
ISO is not an acronym in either of the organization’s official languages and the letters are not delimited with periods like initials. The short-form name is based on the Greek word ἴσος (isos in English), meaning equal. Fitting, since their mission is to equalize and standardize across nations and cultures.
The ISO is the world’s largest developer and publisher of international standards. While not a government organization, it has strong links to governments, and the ISO’s stature gives it the ability to set standards that often become law, either through treaties or national standards.
The organization’s work helps improve international collaboration and communication and promotes steady and equitable growth of international trade. ISO standards encompass most technical and nontechnical fields and affect aerospace, alphabetization and transliteration, chemistry, design, engineering, fuels, image technology, machines, manufacturing, measurements, medical equipment, methods of testing, production, specifications for parts, shipbuilding and tools, among other areas. Most of the standards are reviewed and optimized every five years.
ISO standards are identified in the format:
ISO nnnnn:yyyy: Title
where nnnnn is the number of the standard, yyyy is the year published and Title describes the subject.
EN ISO nnnnn is the European version of the international standard, and BS EN ISO nnnnn is the British variation. Some standards are issued in collaboration with other organizations and are identified accordingly.
Standards not covered by the ISO include electrical and electronic engineering, which is the responsibility of the International Electrotechnical Commission (IEC).
In addition to standards, the ISO also publishes technical reports, specifications, corrigenda and guides. Their documents are copyrighted and they usually charge for copies, however, the organization does not charge for most draft copies delivered in electronic format. Note that drafts are often substantially modified before they are finalized as standards.
ISO standards supplied with our pdCountry database product include:
- ISO 3166-1 alpha-2 – two-letter country code
- ISO 3166-1 alpha-3 – three-letter country code
- ISO 3166-1 numeric – three-digit country code
- ISO 4217 currency code
The product also provides data from the International Telecommunication Union (ITU) and other information sources.
How to Zip & Unzip Files
Posted by: | CommentsWe receive and send a lot of files as part of our data processing services, and some of our clients are unfamiliar with how to zip and extract files. The following instructions show how to compress and uncompress a file under the Windows, Mac and Linux operating environments. Note than under most systems you can select multiple files as well as folders/directories to zip into the same archive.
Zipping a file creates a compressed version of the file that is usually considerably smaller than the original file. The zipped version of the file has a .zip file extension.
Unzipping a file reverses the zip process and extracts the file from the compressed archive.
IMPORTANT: Please be cautious about opening .zip files from unknown e-mail senders because they can contain viruses. Confirm with known senders before opening a .zip file.
WINDOWS ME, XP, SERVER 2003, VISTA, SERVER 2008 and 7
Compress files (zip files)
- Locate the file you want to compress.
- Right-click the file; then point to Send to and click Compressed (zipped) folder.
A new compressed zip file is created in the same location.
Uncompress files (unzip files)
- Locate the compressed zip file you want to extract.
- Do one of the following:
- To extract a single file or folder, double-click the zip file to open it; then drag the file or folder from the archive to a new location.
- To extract the entire contents of the zip file, right-click the zip file; then click Extract All; then follow the instructions on the screen.
Windows 95, 98, 98SE and 2000 do not have built in zip file support, and it is necessary to utilize third-party software to create and extract zip files.
MAC OS X (10–10.4)
Compress files (zip files)
- Use Finder to locate the file you want to compress.
- Control-click or right-click the file icon; then click Compress [. . .]
A new compressed zip file is created in the same location.
Uncompress files (unzip files)
- Use Finder to locate the compressed zip file you want to extract.
- Double-click the file icon.
The files contained in the archive will be extracted to the same location.
MAC OS X (10.5–SNOW LEOPARD)
Compress files (zip files)
- Use Finder to locate the file you want to compress.
- Control-click or right-click the file icon; then click Create Archive of [. . .]
A new compressed zip file is created in the same location.
Uncompress files (unzip files)
- Use Finder to locate the compressed zip file you want to extract.
- Double-click the file icon.
The files contained in the archive will be extracted to the same location.
LINUX
Compress files (zip files)
- Open a shell prompt.
- Enter the following:
zip -r filename.zip filedirA new compressed zip file is created in the selected location.
Uncompress files (unzip files)
- Open a shell prompt.
- Enter the following:
unzip filename.zipThe files contained in the archive will be extracted to the same location as the zip file.
Making a Data Dictionary
Posted by: | CommentsA data dictionary is a document that catalogs the organization, contents and conventions of a database or collection of databases. It lists in written form all the databases, tables, views, fields and data definitions and often information about the table layouts, the relationships between tables and other details about the database schema.
It does not contain the actual data from the database system, only information necessary to manage and utilize it. It is also not an instruction manual, though a data dictionary is often included as part of an instruction manual.
There is no universal standard as to the level of detail in a data dictionary. What is included is dependent on the audience and the complexity of the database infrastructure. System administrators and programmers will usually have a highly detailed document, sometimes complete with visual depictions, while end users may only have the basics.
Below is an example of a data dictionary for a bookkeeping database with three tables. It shows the kinds of information typically included in a data dictionary, however, it is not meant to be all-inclusive. Other columns that might be provided could show if a field takes null values and the precise points where each field begins and ends. If scientific or technical information is involved, a column indicating normative ranges may be useful. The possibilities are myriad.
A data dictionary is an important part of database system documentation. Devoting the resources needed for a quality document will help insure fewer problems and significantly aid in productivity.
EXAMPLE DATA DICTIONARY FOR A BOOKKEEPING DATABASE
Number of Tables: 3
Table: name of the table. Field: name of the field. Rel: Table relationship key (if any); PK = primary key, FK = foreign key; see Foreign Key Relationships. Type: field data type. Width: field width. Dec: number of decimal points (if any). Description: data definition of the field contents.
Foreign Key Relationships: (1) points to Customers table Id field. (2) points to Sales table Invoice field.
| Table | Field | Rel | Type | Width | Dec | Description |
|---|---|---|---|---|---|---|
| CUSTOMERS | ID | PK | Character | 10 | Customer ID number | |
| NAME | Character | 25 | Customer name | |||
| CUST_TYPE | Character | 1 |
Customer type (key):
A = Active
I = Inactive P = Prospect |
|||
| TERMS | Character | 1 |
Payment terms (key):
N = Net Due
P = Prepaid |
|||
| SALES | INVOICE | PK | Character | 4 | Invoice number | |
| CUST_ID | FK (1) | Character | 10 | Customer ID number | ||
| SAL_DATE | Date | 8 | Date of sale | |||
| SAL_AMOUNT | Numeric | 10 | 2 | Amount of sale | ||
| RECEIPTS | ID | PK | Character | 10 | Unique ID number | |
| INV_NUM | FK (2) | Character | 4 | Invoice number | ||
| REC_DATE | Date | 8 | Date of receipt | |||
| REC_AMOUNT | Numeric | 10 | 2 | Amount of receipt |
CASS vs. DSF2
Posted by: | CommentsOne of the questions we are most often asked concerns the difference between CASS and DSF2 address/mail processing. These services have grown more similar in recent years, but there are still important differences.
CASS
CASS – Coding Accuracy Support System – standardizes addresses and improves the accuracy of carrier route, five-digit ZIP, ZIP+4 and delivery point codes that appear on mail pieces. When mailers CASS certify their lists, they can become eligible for bulk mail discounts from the U.S. Postal Service (USPS).
In the past, applying these codes only required that mailing address fall within a valid address range. The address itself was not necessarily accurate. For example, ZIP+4 codes typically represent a range of 100 or fewer house numbers on a given street. While 100-199 Rollins Road may be assigned to ZIP+4 code 91311-7007, not all those house numbers are actual delivery points.
Since November 2, 2006, the USPS has determined that CASS-related discounts will only apply when the agency’s Delivery Point Validation (DPV) process confirms the primary number—or the first line—of the addresses. If the primary street number of an address cannot be confirmed with DPV, then no ZIP+4 code is assigned to the mail. Without a ZIP+4 code, the mail ceases to qualify for postal discounts. DPV is therefore now included with CASS processing.
CASS also integrates Locatable Address Conversion System service (LACSLink) which converts some PO Box and rural route addresses to city-style addresses and updates addresses that have been renumbered or renamed.
CASS processing software is graded by the USPS National Customer Support Center (NCSC), located in Memphis, Tennessee, by processing a test file. To be certified a 98.5% accuracy rate is required.
DSF2
Prior to the November 2006 requirements added to CASS processing, DSF2 – Delivery Sequence File Second Generation – was the only fail-safe method of checking the accuracy of mailing addresses since CASS only determined if the address fell within a valid address range. But DSF2 continues to offer advantages that can make it a good choice.
In addition to all the processing and validation supplied with CASS, DSF2 also provides mailers with other important address attributes. It classifies an address as residential or business, identifies the delivery type—curb-side, door-slot, Neighborhood Delivery and Collection Box Unit (NDCBU) or central delivery—and flags seasonal and vacant addresses.
This information allows for more targeted mailings. For example, a company may want to send out a sample box of laundry detergent—with DSF2 they can target their mailing to residential addresses that do not have a door-slot mailbox since the sample would not fit through the slot.
DSF2 also appends codes that can be used to qualify for USPS Enhanced Carrier Route (ECR) Basic, High Density and Saturation postal discounts. These include Pseudo Delivery Sequence Numbers for walk sequence postal presort discounts and Enhanced Line of Travel codes (eLOT).
• • CASS and DSF2 have similarities and important differences. The choice is determined by the targeting required and the postal discounts that can be qualify for. In both cases, however, users will typically benefit from a significant reduction in undeliverable mail, speedier delivery and lower costs.
Regularly Review Database Systems
Posted by: | Comments
Maintaining a successful database infrastructure requires regular review to establish what is going right and where problems may be lurking. This should consist of close consideration of all aspects of the database system, including: hardware & software, administration & input, documentation, staff & training and disaster recovery.
The frequency of database system reviews is dependent on the size of a company or organization and the complexity of the system. At a minimum, we recommend quarterly reviews, but many situations warrant more frequent action.
Prior to conducting any database system review it is important to establish a set of benchmarks and checklists to compare against the findings.
HARDWARE & SOFTWARE: A database system review should begin with an assessment of the applications, computers, workstations, network servers and other devices that underlie and run the system. Decide if they are meeting the expectations and requirements of end users and if they are doing so efficiently. Needs change and technologies grow rapidly, and keeping on top of the machinery is essential in a competitive environment.
ADMINISTRATION & INPUT: Take a long look at how the database system is administered and the input into the tables. Determine if there has been unauthorized augmentation of a database, particularly rogue changes, or if unapproved or non-standard practices and tools are utilized. This will help maintain the system’s physical and logical models as well as prevent costly downtime and gaps in performance.
DOCUMENTATION: The fun often stops for tech people when they have to hang up their programming tools and put their work down on paper. Consequently, documentation is often lacking for database systems. Make sure this is not the case because end use of the system is highly affected. Documentation should include a data dictionary and reflect the current physical and logical state of the infrastructure as well as be understandable to the less tech savvy.
STAFF & TRAINING: The people part of the review is very important because a database system is only as good as those that run and use it. It is important to align duties properly, and the staff needs to have the necessary expertise and training to adequately leverage the technology and be equipped to handle new complexities in the infrastructure. Investment in this area can reap large rewards.
DISASTER RECOVERY: Last but definitely not least, asses the database system in terms of its ability to recover from a disaster. Backups need to be performed regularly and properly stored, and it is vital this includes offsite backup. Additionally, make sure there is an adequate plan for unforeseen complications and worst-case scenarios and that the system’s immunization against viruses, worms and other web-based attacks is at full strength. This is particularly important when there are substantial changes to the database infrastructure.
• • Database management can become overwhelming as requirements escalate and the volume of data mushrooms. Regular review of a database system is essential to preserve the return on investment, meet objectives and insure long-term success.
