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RE: [sfmysql] Database Design help needed by a beginner

From: James R.
Sent on: Saturday, February 25, 2012 10:55 PM
Hey Tom, would you ever consider in that diagram storing everything as a varchar, with a separate type enum...almost like storing a single java object? I'm not sure if any databases do that...maybe oracle. I also did something similar in one of my systems, but put value_integer, value_varchar, etc all in one table, and had a valueType of 1-6, where 5 of the values would always be null, and the last would either be null or a value. I mention this because it seems like once per year or two, I keep wondering if everything everywhere could be a string (or char bytes). If you happen to call a numerical method on it, it would happen to do that to the best of its ability (almost perl-like). I'd personally like to see this fully proved as not-useful so I can stop making some custom system of my own every 2 years I delete immediately. I suspect it is both too dangerous (not type-safe) and does in the end always hamper performance.

Another comment I have on the EAV diagram is, if you know the data value types are going to be evenly distributed, and you know you will often just want one set...you automatically have a useful database partitioning.  If those conditions are not met...it looks like the correct normalization, but you could start to argue that it is in 4th normal form instead of 3rd (you couldn't argue well, but you could).  And, one typical problem with that 4th form is there are usually too many one-to-ones...but there might be others.  A mapped object in the application level will have to do 6 join links instead of one.  There's always the updateable view, but I'm personally trying to not want to use those.
 

Subject: Re: [sfmysql] Database Design help needed by a beginner
From: [address removed]
To: [address removed]
Date: Fri, 24 Feb[masked]:15:47 -0500

My Zend Framework 2 EAV sparse data matrix engine database diagram is a good learn:

https://github.com/toma42/Stuki/raw/master/documentation/eav_schema.png

Tom

On Fri, Feb 24, 2012 at 1:14 PM, Kieran <[address removed]> wrote:
My rate is $90 per hour.


From: Tendekai Muchenje <[address removed]>;
To: <[address removed]>;
Subject: [sfmysql] Database Design help needed by a beginner
Sent: Fri, Feb 24,[masked]:26:05 PM

I am looking for anyone who can help me with database design. i am trying to create an admin panel for a helpdesk system and need assistance with relational databases and stuff. 

--

Tendi





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