Re: Oracle Contractor's Estimate Too High ?

The person who originally designed the database could probably do it in a day because, presumably, she already has the business knowledge necessary for the task. It is not reasonable to expect an outside person to complete the task in the same amount of time. Databases are designed with an eye to future growth and to current and future performance, among other things. Because of this, knowledge of the data and its use is critical.

I'm guessing it would probably take a few days to acquire the necessary business knowledge, assuming reasonable access to the necessary personnel (they're not on vacation, tied up in meetings, etc.). After that, the actual design can probably be done in a day. Total design time - about a week, given good conditions. One of the most critical factors, given the apparent lack of documentation, is the presence of someone who can explain the thinking behind the current design and how the tables relate to each other.

It seems to me that 120 hours is a bit much for just the design, but probably not too much (maybe not even enough) if the contractor is going to help set up, test and document the database, and port the data from the old to the new. That's only three weeks, and it's hard to string all of these tasks together much more quickly, even under optimum conditions.

tim4321_at_my-deja.com wrote:

> Help ! I'm not sure if my contractor's estimate for working on our
> database is accurate. I'm just a humble perl hacker and know just a
> little bit about database design. If any DBA's out there could read my
> dilemma and post a candid opinion, I would really appreciate it. Thanks
> in advance.
>
> Here's my dilemma:
>
> I am working on an internet project ( 24x7 high availability.. you know,
> the usual ) that uses perl scripts to access an Oracle database.
>
> The database currently has tables with names such as WTDCOMM and fields
> with names like WTDPLNT. Needless to say, everything needs to be
> renamed.
>
> The only documentation is a stack of pages that maps the field and table
> names to terse one sentence descriptions of what they mean.
>
> Ex: WTDCOMM - Table of Common Names
>
> There is no documentation about primary, foreign keys etc.
>
> My only other resource is the SQL from the scripts which currently
> access the database. I also work with the person ( my boss ) who created
> the database so I can pick her brains about it when necessary.
>
> The database consists of about 30 tables. Some tables have over tens of
> thousands of records, some only a few ( less than 20 ). The database and
> the tables were all set up using the default values in the Oracle Schema
> Manager.
>
> Some of the fields have colon delimited values in them:
>
> Ex: :these:are:the:values:in:this:field:
>
> The assumption being that the programmer would use a like statement to
> search this field.
>
> At some point, I realized that the database need to be overhauled,
> optimized for speed, made more better in general. I called in a
> contractor who looked at the database and said that just for the initial
> database design and data modeling it would take about 120 hours. At the
> time, I thought this was reasonable.
>
> Today in a meeting, the head of the IT department said the he could do
> all of the design work in 4 hours and that the person who originally
> designed the database and I should be able to do it in a day.
>
> Our in house sys admin gave us the opinion that it shouldn't be that
> hard and shouldn't take that many hours (120) and said most of our
> optimization would be in the SQL statments and not the database anyway.
> And that we could change things as we go if we need to.
>
> So, am I being screwed by the contractor or does 120 hours seem
> reasonable for a contractor to come in, learn how things work, do the
> data modeling and help up set up the new database ? Please be as candid
> as possible. The difference between the 4 hours quoted by the head of
> the IT department and the 120 quoted by the contractor seems immense.
> Who's right ?
>
> Thanks in advance !
>
> Tim
>
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> Share what you know. Learn what you don't.
Received on Wed Sep 01 1999 - 22:43:59 CDT