Help with Database choice
simonko...@gmail.com
I am relatively new to delphi database programming, i do however have
a reasonable knowledge of database principals etc. The problem...
We currently have our proprietary Inspection software which records
data for the offshore oil industry. It records things like positional
data, user inputted data and geosurvey data, every second. There will
only ever be one or two machines that would be committing/retreiving
data from the database at once. The amount of data could escalate
quite quickly, with data captured every second for periods of up to
three months.
The software (not written by myself) currently uses a local paradox
database, and i am wanting to change to a different database. I have
built some smaller applications in delphi using an access database
through ADO, and i found this to be quite easy to learn and simple to
program. I understand that access has limited abilities, an although
it was fine with my smaller apps, I can see this becoming problematic
with more data.I have a feeling that using an access database for the
inspection software is going to be a hassle bacause i think that there
is a limit to the amount of data access can store.
The database would ideally be located on another 'local' machine,
however this is not a requirement ( it can be the same machine).
Someone has suggested to use Oracle as a database server (which we
have), however after looking at it for a few days, i am stuck and a
bit overwhelmed wioth the complexity of oracle. I had trouble even
connecting to the database.
I have done a bit of reading on thses groups and some people have
suggested MSSQL or Interbase for similar situations to mine. Interbase
i can see comes with delphi, and i would 'think' (any comments?) that
this would be quite similar to using access within delphi.
Anybody with relevant input is welcomed to post. If Oracle is going to
be too complicated to manage (there is going to be no support while
gathering data offshore) i need to consider other databases.
Any help greatly appreciated
Simon
Jerry Von Korff
Have you a basic understanding of SQL?
What operating systems are available?
I've been migrating my Dbase application to MySql. There are going to be
all sorts of people who are experts in the questions you are asking,
perhaps I can offer a couple of thoughts from a sympathetic point of
view as one just now going through the learning process.
I looked at Interbase; I looked at Foxfire--the open source version, and
I settled on MySql. I was looking for a low cost solution. Before you
make the leap, you have to become really familiar with SQL. Working with
an SQL server like MySql is not near as hard as it appears to be at
first. But it takes some months of patient learning. The first step, at
least for me, was to create a replica of some of your tables on your SQL
server, and then to run some SQL queries on those tables, to get a feel
for the difference between retrieving data from a flat file database and
sql server. It is pointless to try to make the transition until you
have a feel for what an SQL server does.
The second step is to choose the connection system. Again, there are
oodles of folks on this forum who can help you with that. I'm using
MyDac, purchased from CoreLabs. They are a VCL based system that
connects to MySQL as seemlessly as the BDE components connect to the
BDE. Instead of Ttable you get TMyTable and instead of TQuery you get
TMyQuery. Other tools work the same way. You can connect them to the
same display components on your form (dbgrid, dbedit...). So your GUI
runs just the same way. You are just collecting data for your dataset
using SQL instead of opening the whole dang Ttable and navigating records.
Now you have to get used to displaying the data that your user wants via
SQL instead of the old way. It takes a couple of weeks of doodling
until a light-bulb goes off, and then you are on your way.
I transitioned my program form by form--or I should say am
transitioning, by saving out the project form with SQL in the name:
WpMain becomes WPSqlMain, and so on. Its a big job, but not impossible.
You are going to need to develop a method of importing your data from
the old program to the new. There are utilities, or you can write your
own procedures to accomplish that objective.
Good luck.