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Posted by Lόpher Cypher on 01/03/06 20:45
frizzle wrote:
>>> As you said in the beginning :)
>>>
>>> TABLE Category
>>> ID
>>> ...
>>> ParentID ... REFERENCES Table(ID)
>>>
>>> TABLE Thread
>>> ID
>>> ...
>>>
>>> TABLE Message
>>> ID
>>> ...
>>> ThreadID ... REFERENCES Thread(ID)
>>> ReplyTo ... REFERENCES Message(ID)
>>>
>>> is one possibility coming from
>>>
>>> 1) Category may have subcategories (0..*)
>>> 2) Subcategory must have parent category (1)
>>> 3) Category consists of threads (0..*)
>>> 4) Thread consists of messages (1..*)
>>> 5) Message could either be top-level or a reply to one of the messages
>>> in thread
>>>
>>> Another possibility is a "linear" thread, i.e. posts are simply listed
>>> one after another, in which case there is no ReplyTo field.
>>> I wouldn't say that having a table for each thread is a good design.
>>>
>>> Read some on relational database design :)
>>> Btw, I think this is rather a topic for design or sql group :) Has
>>> nothing to do with PHP :)
>>>
>>>
>> --
>> Scot McConnaughay
>
> Well, thanks for the replies, and continuing the discussion here ...
> It would certainly be a big bunch of duplicate fields, with exact the
> same structure.
>
> I know it would go against normalization, but on the other hand, i
> thought it'd get a big deal faster if it knew in what table to search
> immediately,
I doubt it greatly :)
> without skipping 1000-nds of comments not concerning the current
> thread.
> Maybe i'm just underestimating the power of PlayStat ... erm, mySQL.
Don't forget about indexes :) The primary key is always indexed so,
there is no "skipping" records. Event a binary tree index would get
there fast :) Say, if you have 16 million threads with 16 millions
consequent ids, and you want to retrieve 15.999.999-th record, you won't
have to skip 16 million records to get there :) With binary tree, it'll
only take 32 steps :)
>
> I don't know beforehand how popular this forum will be, and how many
> threads, and comments will be in it. I'm just affraid that it'll get
> slow.
It is more likely that it'll be slow if the server won't be able to
handle the load :)
--
- lΓΌpher
---------------------------------------------
"Man sieht nur das, was man weiΓ" (Goethe)
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