Databases Reference
In-Depth Information
Although there are many different
Database Management Systems (DBMS)
out
there, we can, for our purposes, group them into three different categories:
• Those that provide connectivity via ODBC/OLE DB drivers (we'll talk about
what these are in a moment).
• Those that use proprietary systems with no standard connectivity.
• Those that are not necessarily DBMSs, but rather have tables stored in plain
files, such as Excel, CSV, TXT, XML, and the like.
We'll discuss some key points in each of these categories so we have a general
understanding of the implications we must consider.
Using ODBC and OLE DB drivers
First, what the acronyms mean:
•
Open Database Connectivity (ODBC)
•
Object Linking and Embedding Database (OLE DB)
You may already know what these are, and we will not go into detail about how
these drivers work on the inside but, in general terms, we can think of them as
"query translators", which enable the communication between an application (such
as QlikView) and the DBMS. Since they have been in use for a long time, almost all
major DBMS vendors provide access via ODBC and/or OLE DB drivers.
Installing the drivers
When you use a printer, it requires you to install a driver on your computer so the
documents you send to print can be received and printed properly. The same is true
with the DBMS drivers. You need to install the corresponding driver on the machine
you will be sending queries from in order for them to be accurately translated and
properly processed by the DBMS, which will, in time, respond to it by sending the
requested set of data.
Some common drivers will be installed along with the Windows
installation. So, depending on the driver, you might not need to
install any additional drivers.
