Re: [HACKERS] Re: ORDBMS
От | Chris Bitmead |
---|---|
Тема | Re: [HACKERS] Re: ORDBMS |
Дата | |
Msg-id | 3894D813.3C2EE1BF@bitmead.com обсуждение исходный текст |
Ответ на | Re: [HACKERS] Re: ORDBMS (The Hermit Hacker <scrappy@hub.org>) |
Список | pgsql-hackers |
The Hermit Hacker wrote: > Not quite an answer to your question, but my guess is that 'address > ADDRESS' would contain a pointer (OID) to the address table ... so the > person table would be realtively small in comparison to the address table I'm 99% sure that this is not the case. Rather the address is embedded inside the person object. I think this is basicly what Oracle has done with 8i too. I think then if you do SELECT * from person it flattens out all the fields. (This might even still work). Not that the idea of relating to oid as another feature is bad. My last message I gave the example of how postquel could do this. I think that design had the advantage that you could construct 1:M relationships this way too. Just a trade off a bit like in C++ class Person {Address address; } vs class Person {Address *address; } vs class Person {List<Address> addresses; } pros and cons for each one. > The way I look at the above, its a 'JOIN' at table create time, based on a > unique value, the OID ... > > How 'dep' can you go with this? ie: > > CREATE TABLE address (street TEXT, number TEXT, suburb TEXT, zip TEXT); > CREATE TABLE telephone ( home TEXT, business TEXT, fax TEXT ); > CREATE TABLE person (name TEXT, address ADDRESS, telephone TELEPHONE); > > Question, if I did an INSERT person VALUES ('myname'); > > What happens to the address table? a row gets created with all NULL? Or? > > The reason I ask is the way it was taught to me was that an RDBMS gains > its benefit through normalization and joins ...with the outer join syntax > coming up, if you had a table of 'person' fully populated, but only > address info for 1/2 of them, you could still get all 'people', while your > 'address' table has 1/2 the tuples of the person one ... space savings ... > > HSorry, rambling thoughts out o fmy head without putting them together > very well :) > > Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy > Systems Administrator @ hub.org > primary: scrappy@hub.org secondary: scrappy@{freebsd|postgresql}.org
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