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What are the disadvantages of normalizing a table in a database?
All databases tend to be normalized to some degree; in fact, a relational database almost must adhere to a minimum of 1NF to be useful. However, the more a database is normalized, the greater the impact of processing time of queries is likely to be. For one thing, higher levels of normalization results in larger numbers of decode tables and the like, requiring more table joins in retrieval queries and more referential integrity overhead.
Normalization is a complex process but it is a factor for successful database design. Justify this statement?
Normalization is the process of efficiently organizing data in a database. There are two goals of the normalization process: eliminating redundant data (for example, storing the same data in more than one table) and ensuring data dependencies make sense (only storing related data in a table). Both of these are worthy goals as they reduce the amount of space a database consumes and ensure that data is logically stored.
What is a one-to-many relationship?
It is a term from computer databases. A relational database can have a one-to-many relationship in its data. For example, if you have a customer order database, one table will contain customer names and another will contain their orders. Each customer will only be listed once, but each customer can make many orders. So one customer can be related to many orders. Incorporating that into a database requires the creation of a one to many relationship.
Is data duplication is a desirable aspect of a database?
No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.No it is not. A well designed database will have no duplication. Duplication of data takes up more space. It can also lead to inconsistencies in the data. If the same data is there more than once, it can sometimes that not all copies of it are changed when they have to be. So for example, you could have a person listed twice in a database. If they got a new phone number and this was only changed in one of the entries for them on the database, you would now have the same person listed twice, but with each having a different phone number. If they are on the system once only, then there cannot be those kinds of inconsistencies.
What is the difference between Dynaset and snapshot in VB?
a dynaset object can be used to retrieve information from a recordset and use the resault of the query to then edit the records and it also can get resaults from more than one table. On the other hand the snaphot gets information from only one table on the query and the data can not be edited or updated
It is possible to have more than one table in a relational database?
You have to have more than one table in a relational database. In a relational database tables are designed to be related to other tables, so there has to be a minimum of two tables. Quite often there are a lot more than two.
What is a file on a database?
More than one record in a Database
What is key in rdbms?
When a database table has a key which consists of more than one field, a partial key refers to any one of those fields.
In a relational database can two or more tables be liked to appear as one table?
Yes. That is how relational database work.
What is the meaning of key in database?
A key is one or more fields in a database table which can be used to help identify a particular row of the table. A primary key is one such that uniquely defines a single given row. A foreign key is a set of one or more fields in one table which is the primary key to a row of another table.
What is partial key in RDBMS?
When a database table has a key which consists of more than one field, a partial key refers to any one of those fields.
How does join operations affect the performance of database?
Joins affect the performance of queries because we are trying to fetch and display data pertaining to more than one table. The more complex the join, the more time the database takes to return the results. Since the database has to consolidate/check the data from multiple tables to return you the output, the performance is not as good as what it does when you are querying a single table.
What does the term record mean in a database?
a record is something that you hold data on one specific field consisting of more and you can have as much records you want
What is RBDMS?
RDBMS stands for Relational Database Management System. RDBMS data is structured in database tables, fields and records. Each RDBMS table consists of database table rows. Each database table row consists of one or more database table fields.RDBMS store the data into collection of tables, which might be related by common fields (database table columns). RDBMS also provide relational operators to manipulate the data stored into the database tables. Most RDBMS use SQL as database query language.
What is multiuser database?
That is a database that can allow simultaneous record entry by more than one person.
Is a table a collection of records for a single object?
A table in a database contains a collection of records (or rows). Each record contains one or more fields (or columns).
Which type of database model is similar to a hierarchical database but allows each child record to have more than one parent record?
Network Database
