Assingment2
ITC 6000 Class 2 ‐ Assignment
1. List at least four advantages of indexing. Mention some indexing tips that would be of particular help to a database designer. Also, discuss indexing practices that can adversely affect the performance of a database. In your discussion, include information on how a designer should decide on how many indexes to provide per table.
Indexes are used to boost performance in a database. Finding an individual record or set of records most efficiently done by Index. Index key is the reference point where an index is an ordered arrangement of keys and pointers. Each key is appointed to the location of the data recognized by the key. For example: when we print out at the NEU library we have given our User ID so when we print out we can easily find the documents.
If no index exists on a table, a table scan must be performed for each table referenced in a database query. The larger the table, the longer a table scan takes because a table scan requires each table row to be accessed sequentially. Although a table scan might be more efficient for a complex query that requires most of the rows in a table, for a query that returns only some table rows an index scan can access table rows more efficiently. Although indexes can reduce access time significantly, they can also have adverse effects on performance.
A designer have to determine whether the maintaining the index and the additional space consumed by the index is worth in order for the performance gain you get from the queries that use the index.
2. List at least four basic rules for identifying primary keys in a relational database. Mention how you would go about identifying the foreign keys in your design. Briefly discuss foreign key ownership and how to indicate a foreign key in your relational database model.
A primary key is a field or group of fields in a database that make a unique identifier for each row of information. Primary keys are particularly important because they can
1. List at least four advantages of indexing. Mention some indexing tips that would be of particular help to a database designer. Also, discuss indexing practices that can adversely affect the performance of a database. In your discussion, include information on how a designer should decide on how many indexes to provide per table.
Indexes are used to boost performance in a database. Finding an individual record or set of records most efficiently done by Index. Index key is the reference point where an index is an ordered arrangement of keys and pointers. Each key is appointed to the location of the data recognized by the key. For example: when we print out at the NEU library we have given our User ID so when we print out we can easily find the documents.
If no index exists on a table, a table scan must be performed for each table referenced in a database query. The larger the table, the longer a table scan takes because a table scan requires each table row to be accessed sequentially. Although a table scan might be more efficient for a complex query that requires most of the rows in a table, for a query that returns only some table rows an index scan can access table rows more efficiently. Although indexes can reduce access time significantly, they can also have adverse effects on performance.
A designer have to determine whether the maintaining the index and the additional space consumed by the index is worth in order for the performance gain you get from the queries that use the index.
2. List at least four basic rules for identifying primary keys in a relational database. Mention how you would go about identifying the foreign keys in your design. Briefly discuss foreign key ownership and how to indicate a foreign key in your relational database model.
A primary key is a field or group of fields in a database that make a unique identifier for each row of information. Primary keys are particularly important because they can