RE: New SQL Datatype RECURRINGCHAR
| От | David Bennett | 
|---|---|
| Тема | RE: New SQL Datatype RECURRINGCHAR | 
| Дата | |
| Msg-id | NEBBIHDFALGPGDHNLKBBAEHFCJAA.dbennett@bensoft.com обсуждение исходный текст  | 
		
| Ответ на | Re: New SQL Datatype RECURRINGCHAR (Alex Pilosov <alex@pilosoft.com>) | 
| Список | pgsql-hackers | 
>> It's apparent that there is a lot of duplicate space used in the storage
>> of this information.  The idea is if order.status was stored as a
>> RECURRINGCHAR
>> then the only data stored for the row would be a reference to the value
of
>> the column. The actual values would be stored in a separate lookup table.
>You should instead have another table with two columns, order_status_id
>and order_status_desc, and join with it to get your data.
The idea is to simplify the process of storing and accessing the data.
Joins required
a deeper knowledge of the relational structure.  This also complicates
application
programming,  two tables must be maintained instead of just one.
>>     select distinct {RECURRINGCHAR} from {table}
>>
>>    can be radically optimized
> select distinct order_status_desc from order_status_lookup
Again the idea is to simplify.  Reduce the number of tables required to
represent a business model.
>>  - Eliminates use of joins and extended knowledge of data relationships
>>           for adhoc users.
> For adhoc users, you can create a view so they won't be aware of joins.
Now we have a master table,  a lookup table AND a view?
even more complication....
>> It is often an advantage to actually store an entire word representing a
>> business meaning as the value of a column (as opposed to a reference
>> number or mnemonic abbreviation ).  This helps to make the system
>> 'self documenting' and adds value to users who are performing adhoc
>> queries on the database.
> No, that is against good database design and any database normalization.
I would like to hear your argument on this.  I don't see how optimizing
the storage of reference value breaks a normalization rule.
--Dave
		
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