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Database Programming
Databases are collections of tables that maintain and display information, often collaboratively; this information can be used for interaction with an application or gaining general knowledge. Questions about database engines and modifying or using them belong in this category.
8,803 Questions
What kinds of data are used by a systematist?
Systematists use data taken from fossils, homologous features, and embryologic data.
What is garbage in garbage out in database?
It means if you enter "rubbish" information into a database, you'll only get "rubbish" information out.
So check any data that is going to be inputted into a DB.
Something (x) which can be regarded as forming one single, large:
[e.g. nature: large block of stone, business: firm, etc.], and exists in its own right.
What is the role of normalization?
In broad-spectrum, normal flora are not invasive and do not usually cause disease. They occupy niches that supply their requirements for nutrients, oxygen and space to reproduce. They may provide some benefits in unknown vitamins, or some discomfort as they produce gas from undigested food.
What is the purpose of using joins in database is normalization the only purpose of it?
The purpose of using Normalization is to avoid the data redundancy in tables. The normalized schema is much faster in performance so you can get a quick response from the database.
OLTP database designers follow the Normalization rules but the tables in Data warehousing(OLAP) data bases are in the De normalized form, they won't follow the Normalization technique. For this reason we are using more complex queries in Data warehouses which uses more system resources.
Some one might explain you better way.........
Thanks
Blueberry
What are advantages and disadvantages of circular queue over ordinary queue?
Circular queues are very efficient and work well with low level codes. Ordinary queues are the standard type of queue but they do not maximize memory data well.
What are the three update commands in sql?
The three update commands in SQL are SET, WHERE, AND FROM.
select
What is Attribute in system analysis?
Knowledge of organisation
Knowledge of computers and software
Good interpersonal relations
Ability to communicate
Analytical mind
Breadth of knowledge
What is the difference between a reporting entity and a taxable entity?
the difference between a reporting entity and a taxable entity is, a reporting entity is the company or organization and the taxable entity is the individual.
What four main types of actions involve databases?
self-describing nature of a database system.
insulation between programs and data, and data abstraction.
support of multiple views of the data.
sharing of data and multiuser transaction processing.
What is transaction processing in dbms?
Transaction processing is information processing that is divided into individual, indivisible operations, called transactions. Each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state. Transaction mandatorily requires acknowledgment to get received as a necessary feedback for accomplishment.
Transaction processing is designed to maintain a computer system (typically a database or some modern filesystems) in a known, consistent state, by ensuring that any operations carried out on the system that are interdependent are either all completed successfully or all canceled successfully.
For example, consider a typical banking transaction that involves moving $700 from a customer's savings account to a customer's checking account. This transaction is a single operation in the eyes of the bank, but it involves at least two separate operations in computer terms: debiting the savings account by $700, and crediting the checking account by $700. If the debit operation succeeds but the credit does not (or vice versa), the books of the bank will not balance at the end of the day. There must therefore be a way to ensure that either both operations succeed or both fail, so that there is never any inconsistency in the bank's database as a whole. Transaction processing is designed to provide this.
Transaction processing allows multiple individual operations to be linked together automatically as a single, indivisible transaction. The transaction-processing system ensures that either all operations in a transaction are completed without error, or none of them are. If some of the operations are completed but errors occur when the others are attempted, the transaction-processing system "rolls back" all of the operations of the transaction (including the successful ones), thereby erasing all traces of the transaction and restoring the system to the consistent, known state that it was in before processing of the transaction began. If all operations of a transaction are completed successfully, the transaction is committed by the system, and all changes to the database are made permanent; the transaction cannot be rolled back once this is done.
Transaction processing guards against hardware and software errors that might leave a transaction partially completed, with the system left in an unknown, inconsistent state. If the computer system crashes in the middle of a transaction, the transaction processing system guarantees that all operations in any uncommitted (i.e., not completely processed) transactions are cancelled.
Transactions are processed in a strict chronological order. If transaction n+1 intends to touch the same portion of the database as transaction n, transaction n+1 does not begin until transaction n is committed. Before any transaction is committed, all other transactions affecting the same part of the system must also be committed; there can be no "holes" in the sequence of preceding transactions.
What are the Disadvantages of numerical filing system?
A numerical filing system will need a way to look up a patient's name in order to get their chart number. This can take a little longer than simply finding a file by alphabetical order.
Can database be used for calculations?
No, databases can only do a selective amount of calculations, but you can get the exact same responses but many more detailed calculations by using Spreadsheet software, I recommend using Microsoft Excel.
What are the disadvantages of a paper based diary system?
There can be many
disadvantages of a paper diary as they are sometimes illegible-but this differs
from user to user. The legibility of the diary is very important especially
when other colleagues are in touch with the diary for specific information or dates-as
some people do not have legible handwriting, it becomes harder for other
colleagues to access the information properly. The paper diary can be lost
easily and if an opposing business member gets hold of it many vital
information can be lost. Paper diaries can be damaged very easily if substances
such as water spill on it.
It cannot be edited very easily as it is handwritten whereas if it were on the
electronic diary you could just edit your work by deleting the specific
information and retyping the edited information up. It is not as reusable as
the electronic diary as new diaries will have to be brought every year. Paper
diaries can be very large, massive and stout in size
What advantages does a live system have over an installed system?
what is a live system? what advantages does it have over an installed system?
1. Live System- A computer that runs the Wide Area Progressive games and displays the main system window. Advantages- Customization, cost, free market, stability, and community.
What is the meant by anomaly in database?
Data anamaly means same type of data present in database as a duplication.So while updating or modifying the information in the database we gets the problem of data inconsistency to solve this problem we need to remove the duplicated data
What are anomalies in database?
Anomalies is the data within the database; it is the copy of the original data it needs to be updated in order to avoid problems such as viewing the website. There are four types of anomalies which are Insertion anomaly, Deletion anomaly, Duplicate entry and Modify (Update anomaly).
Insert anomaly is the entity that relates to another entity within the table. If the data doesn't relate to another entity then there is no point of entering it, therefore a unique data is needed to identify a particular data to insert the data that relates with it such as employee ID number.
Example of insert anomaly: If any company's manager need to insert their employee salary to the employee's ID, they then need to make sure that the employee id is correct otherwise, if it's wrong then they will give unfair salary to their employee by which they will have bad name onto their company.
