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Home -> Community -> Mailing Lists -> Oracle-L -> (Fwd) RE: object tables
Sean / Ed,
I have worked some with object tables and have found them to be better in most cases. For normal select, update, etc. operations, they work the same as ordinary tables. I am assuming you are referring to the ability to REF a row in an object table. A lot of it comes down to design. The three most important things to remember about developing object-relational schemas is design, design, design. There is little room for error. If you want to change the base type of something, you have to drop and recreate the objects. This is really a pain with tables. I think that versioning is due with 8.2. Something to remember is that you can still implement normal relational referential integrity between an object table and other tables. You just need to design the referential columns into the type. Where I have seen the biggest payoff with object tables is in java with web apps.
This is a high-level description of a simple demonstration I used to present some of the benefits of using Oracle's object-relational features to some java developers.
I have a contact table that is an object table created off of my contact_type object. I then create a contact_ref_type that is a REF of contact_type. Next is a contact_ref_nt_type that is a nested table type of the reference type. I then create a customer table that contains a column called contacts that is of the nested table type. In java, I then can populate a customer object that contains a list of oracle.sql.REF contact elements. While iterating through the list, I can use the getValue() function and return the contact object without ever having to join to the contact table. Theoretically, you can take this model and make it as complex as you want and provide the capability to navigate through your entire database with only one select against one table. That makes object tables an incredibly powerful asset to an application design.
Dealing with and manipulating the data in an object-relational schema requires a slight learning curve with PL/SQL and SQL. However, I believe it offers a panacea of benefits to application design.
Hope this helps,
Glen
-----Original Message-----
Sent: Friday, November 03, 2000 5:10 AM
To: Multiple recipients of list ORACLE-L
Hi Folks,
Ed, I must have been reading your mind as I was creating this post when digest arrived!. I've also got the same curiosity as Ed. Whilst recognition of objects in Oracle, make developers life easier I'm curious too about performance. I suspect Oracle jumped on the Object backwagon and provide the functionality but I wonder if there is a genuine practical application in use out there. Anyone seen any papers on this subject?. I believe Oracle does not support Inheritance for Objects, can anyone confirm this to me please.
Sean :)
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>------------------------------------------------------------ > > From: "Shevtsov, Eduard" < E S h e v t s o v @ f l a g s h i p . r u > > Date: Thu, 2 Nov 2000 11:04:06 +0300 > Subject: object tables > >Hello List
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