Advantages for a Logical Data Model
Easy to understand
Logical data models are easy to understand by most users; this basically means that most people can identify what information goes where within the database; this is because all the attributes, entities and relationships are listed clearly, that is why it is easier to understand.
Easy to visualize the activity of the business
Logical Data models also help the user to identify what the activities of the business are. This is an advantage because it is easily identifies of what type of information relates to the business such as:
Customer ID
Address
Name etc.
Construction of LDM and ERD
When constructing the logical data model itself, it is very easy because all the information is laid out clearly; the other use for the construction is that it is not time consuming for small databases, all information is transferred into a diagram with less words.
Disadvantages for a Logical Data Model
Maybe difficult to modify
Logical data models may be hard to change when need modifying, this is because when one set of data needs editing there also may be other related information linked to them, the user will then have to modify all data to make sure the LDM is correct and up to date.
Not easy to spot errors
Spotting errors within a logical data model can become difficult at times as they are not easy to identify. For example if a logical data model is created for a large database then there is a chance of this problem occurring such as inserting the wrong attribute with the wrong sets of data, the user will then have to go back t the start and edit the mistakes made.
Does not have fine details
Logical data models do not consist of fine details, which basically mean that attributes are not described properly or they are not broken down into smaller pieces of data; that is why at times it may be difficult to understand.
Time Consuming
Logical data models are time consuming especially for large database, large databases consist of lots of information and it may cause difficulty when creating a LDM for each of the attribute and entities linked to it. It is important that it is done accurately as it will also be a waste of time when coming back to edit all information again. Diagrams may not be updated but the rest of the information will; this is also time consuming when coming back to the start and linking all information together.
Easy to understand
Logical data models are easy to understand by most users; this basically means that most people can identify what information goes where within the database; this is because all the attributes, entities and relationships are listed clearly, that is why it is easier to understand.
Easy to visualize the activity of the business
Logical Data models also help the user to identify what the activities of the business are. This is an advantage because it is easily identifies of what type of information relates to the business such as:
Customer ID
Address
Name etc.
Construction of LDM and ERD
When constructing the logical data model itself, it is very easy because all the information is laid out clearly; the other use for the construction is that it is not time consuming for small databases, all information is transferred into a diagram with less words.
Disadvantages for a Logical Data Model
Maybe difficult to modify
Logical data models may be hard to change when need modifying, this is because when one set of data needs editing there also may be other related information linked to them, the user will then have to modify all data to make sure the LDM is correct and up to date.
Not easy to spot errors
Spotting errors within a logical data model can become difficult at times as they are not easy to identify. For example if a logical data model is created for a large database then there is a chance of this problem occurring such as inserting the wrong attribute with the wrong sets of data, the user will then have to go back t the start and edit the mistakes made.
Does not have fine details
Logical data models do not consist of fine details, which basically mean that attributes are not described properly or they are not broken down into smaller pieces of data; that is why at times it may be difficult to understand.
Time Consuming
Logical data models are time consuming especially for large database, large databases consist of lots of information and it may cause difficulty when creating a LDM for each of the attribute and entities linked to it. It is important that it is done accurately as it will also be a waste of time when coming back to edit all information again. Diagrams may not be updated but the rest of the information will; this is also time consuming when coming back to the start and linking all information together.
