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31

Can age be a composite attribute? No. age is a function of birthdate and now. age = now - birthdate So, what about birthdate? Can it be a composite attribute? Yes, it can, but it only makes sense to store dates as a composite in data warehousing situations. Often, when warehousing data, you would store year, month, and day as separate things to make it ...


6

Yes, you can store Age as a composite of year, month, date, hour, minute, second in the database if you want to. However this is probably not a good idea in most cases, because Age can be derived from other values that are usually preferable to have stored in the database. The main reason is that it is better to store birthdate rather than Age; because ...


3

An E-R diagram simply displays the objects (entities) and how they relate to one another. So, to draw your diagram, first identify your objects. These are often identified by nouns (people, places, things - and objects are things). We'll start with the following: Bus Reservation From there, each object has certain attributes that help describe them (...


2

SQL servers will offer specific products such as DTS or SSIS for importing data. These can be pretty optimised and run very quickly. However!! If you have programming skills I highly recomend you write your own importing software. The reason for this is that although the Sql server may be able to run an import process faster in a best case senario, it is ...


2

A schema is collection of database objects that are logically grouped together. These can be anything, tables, views, stored procedure etc. Schemas are typically used to logically group objects in a database. For example, an application that has reporting and auditing components may have 2 schemas called reporting and auditing with a collection of tables, ...


2

If your application is local (doesn't support remote access) you could use an embedded DB engine. It gives you the easy installation and independence from other installed programs. So you need to choose the appropriate library. What to look for when choosing? As I said, the library should be embedded. It lets you create the single executable file without ...


2

In layman's terms: Usually age is not stored since it's such a volatile attribute. It changes by the second. So storing it is an universally recognized bad idea. Usually date of birth is stored instead. What you want is a representational requirement that can be easily calculated at presentation time or in a database view by writing a rather trivial ...


1

The benefit and problem with triggers are two sides of one coin. Once defined they will always be executed. This means future application code will always have notifications baked in and the programmer, no matter how new, will not forget to add it. Conversely some future requirement that does not need notification cannot avoid it. You know your application ...


1

Not sure if you've resolved this by now. I agree the SQL route is probably the way to go, but I think your primary question is the best way in T-SQL to compare the staging data to the target table and insert/update as necessary, right? I think looping would end up being relatively slow for this scenario. I'd use a MERGE for the students, as Keith Miller said,...


1

The Distributed Relational Database Architecture (DRDA) Version 5 standard is available online as a free PDF download from The Open Group's Publications Catalog. It comprises 3 volumes: C112 DRDA V5 Vol. 1: Distributed Relational Database Architecture (806 pages) https://www2.opengroup.org/ogsys/jsp/publications/PublicationDetails.jsp?publicationid=12360 ...


1

First of all, where you see hierarchy, a database expert sees relations. Take some time understanding the relational database model and make a simple model that fits your data. This classical model is tried and tested, based on mathematical foundations and is the basis for virtually every large system out there. Do not be misled by people claiming a graph ...


1

First of all. Do not bother much about it. When you separate your concerns well, retrieve data, from processing and displaying it, you will always have the chance to switch to a "better" system. Sizes of about 10,000 entries is nothing a database will complain about, even million sets aren't a big deal. Your database will have to grow as your application/...


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