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* Re: Database Design Question
@ 1970-01-01 00:00 omid omoomi <[email protected]>
0 siblings, 0 replies; 9+ messages in thread
From: omid omoomi @ 1970-01-01 00:00 UTC (permalink / raw)
To: [email protected]; [email protected]; pgsql-general
Hi,
In addition I think, using that integer primary keys would be useful for the
databases which does not support CASCADE ON UPDATE.
Say you would have to change a PartType for any reason,using the integer
format, you will face no problem on tables integrity, updating the
description at the PartTypes table.
But currently PG supports the CASCADE UPDATEs.
Omid
>From: [email protected] (Andre Schnabel)
>To: "Gonzo Rock" <[email protected]>, <[email protected]>
>Subject: Re: [GENERAL] Database Design Question
>Date: Fri, 27 Jul 2001 21:06:50 +0200
>
>Don't really know, if I am a crack .. but ...
>
>Your 1st Design would be faster when joining the tables in a query or view.
>Furthermore an index on the id's (should be integers, right?) would use
>much less storage space than an index on character-fields.
>
>The 2nd design is preferred by theoretical purists. The data are much more
>selfexplaining. If you only have a Parts-record you can see to which
>Parttype an Costumer it belongs without qeurying the other tables. With
>your 1st design you had to.
>
>I think it's a question of performance, storagespace and readability.
>If you need high performace use the 1st Design.
>If you need a design, readable by people who don't work day by day with it,
>use the 2nd method.
>
>It's only my opinion, must not be right.
>
>CU,
>Andre
> ----- Original Message -----
> From: Gonzo Rock
> To: [email protected]
> Sent: Friday, July 27, 2001 8:03 PM
> Subject: [GENERAL] Database Design Question
>
>
> A Question for those of you who consider yourself crack Database
>Designers.
>
> I am currently moving a large database(100+Tables) into pgSQL... with
>the intention of deploying against 'any' SQL database in the future. The
>development side will be rigorously using Standard SQL constructs with no
>unique/proprietary extensions.
>
> My question concerns establishing the relationships.
>
> Currently Relationships between tables are established via a Unique
>Integer ID like this:
>
> *=APrimaryKey
>
> PartTypes Customer Parts
> --------- -------- -----
> PartTypeID CustomerID PartID
> *PartType *Customer PartTypeID
> Address CustomerID
> *PartNumber(2FieldPrimaryKey)
> *PartRevision(2FieldPrimaryKey)
> PartName
>
>
> HOWEVER; I have read lots of texts describing the Relational Design
>should be instead like this:
>
> *=APrimaryKey
>
> PartTypes Customer Parts
> --------- -------- -----
> *PartType *Customer PartType
> Address *PartNumber(2FieldPrimaryKey)
> *PartRevison(2FieldPrimaryKey)
> PartName
> Customer
>
> Both Techniques have a unique foreign key back to the parent tables but
>one uses No.Meaningful.Info.Integer.Data for the ForeignKey while the
>second uses Human.Understandable.ForeignKeys
>
> Is one recommended over the other??? Sure appreciate the commentary
>before I get in too deep with all these tables.
>
> Thanks!
>
>
>
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>
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^ permalink raw reply [nested|flat] 9+ messages in thread
* Database Design Question
@ 2001-07-27 18:03 Gonzo Rock <[email protected]>
0 siblings, 1 reply; 9+ messages in thread
From: Gonzo Rock @ 2001-07-27 18:03 UTC (permalink / raw)
To: pgsql-general
A Question for those of you who consider yourself crack Database Designers.
I am currently moving a large database(100+Tables) into pgSQL... with the intention of deploying against 'any' SQL database in the future. The development side will be rigorously using Standard SQL constructs with no unique/proprietary extensions.
My question concerns establishing the relationships.
Currently Relationships between tables are established via a Unique Integer ID like this:
*=APrimaryKey
PartTypes Customer Parts
--------- -------- -----
PartTypeID CustomerID PartID
*PartType *Customer PartTypeID
Address CustomerID
*PartNumber(2FieldPrimaryKey)
*PartRevision(2FieldPrimaryKey)
PartName
HOWEVER; I have read lots of texts describing the Relational Design should be instead like this:
*=APrimaryKey
PartTypes Customer Parts
--------- -------- -----
*PartType *Customer PartType
Address *PartNumber(2FieldPrimaryKey)
*PartRevison(2FieldPrimaryKey)
PartName
Customer
Both Techniques have a unique foreign key back to the parent tables but one uses No.Meaningful.Info.Integer.Data for the ForeignKey while the second uses Human.Understandable.ForeignKeys
Is one recommended over the other??? Sure appreciate the commentary before I get in too deep with all these tables.
Thanks!
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Database Design Question
@ 2001-07-27 19:06 Andre Schnabel <[email protected]>
parent: Gonzo Rock <[email protected]>
0 siblings, 1 reply; 9+ messages in thread
From: Andre Schnabel @ 2001-07-27 19:06 UTC (permalink / raw)
To: Gonzo Rock <[email protected]>; pgsql-general
Don't really know, if I am a crack .. but ...
Your 1st Design would be faster when joining the tables in a query or view. Furthermore an index on the id's (should be integers, right?) would use much less storage space than an index on character-fields.
The 2nd design is preferred by theoretical purists. The data are much more selfexplaining. If you only have a Parts-record you can see to which Parttype an Costumer it belongs without qeurying the other tables. With your 1st design you had to.
I think it's a question of performance, storagespace and readability.
If you need high performace use the 1st Design.
If you need a design, readable by people who don't work day by day with it, use the 2nd method.
It's only my opinion, must not be right.
CU,
Andre
----- Original Message -----
From: Gonzo Rock
To: [email protected]
Sent: Friday, July 27, 2001 8:03 PM
Subject: [GENERAL] Database Design Question
A Question for those of you who consider yourself crack Database Designers.
I am currently moving a large database(100+Tables) into pgSQL... with the intention of deploying against 'any' SQL database in the future. The development side will be rigorously using Standard SQL constructs with no unique/proprietary extensions.
My question concerns establishing the relationships.
Currently Relationships between tables are established via a Unique Integer ID like this:
*=APrimaryKey
PartTypes Customer Parts
--------- -------- -----
PartTypeID CustomerID PartID
*PartType *Customer PartTypeID
Address CustomerID
*PartNumber(2FieldPrimaryKey)
*PartRevision(2FieldPrimaryKey)
PartName
HOWEVER; I have read lots of texts describing the Relational Design should be instead like this:
*=APrimaryKey
PartTypes Customer Parts
--------- -------- -----
*PartType *Customer PartType
Address *PartNumber(2FieldPrimaryKey)
*PartRevison(2FieldPrimaryKey)
PartName
Customer
Both Techniques have a unique foreign key back to the parent tables but one uses No.Meaningful.Info.Integer.Data for the ForeignKey while the second uses Human.Understandable.ForeignKeys
Is one recommended over the other??? Sure appreciate the commentary before I get in too deep with all these tables.
Thanks!
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/users-lounge/docs/faq.html
^ permalink raw reply [nested|flat] 9+ messages in thread
* PostgreSQL to Dia program
@ 2001-07-27 20:21 Brent R. Matzelle <[email protected]>
parent: Andre Schnabel <[email protected]>
0 siblings, 1 reply; 9+ messages in thread
From: Brent R. Matzelle @ 2001-07-27 20:21 UTC (permalink / raw)
To: pgsql-general
Someone just posted a PostgreSQL to Dia automatic diagram
creation tool. I have not tested it, but if it works it could
be a huge help.
http://www.zort.ca/postgresql/
Justin, this could definately be a techdocs link.
Brent
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^ permalink raw reply [nested|flat] 9+ messages in thread
* RE: [SQL] Database Design Question
@ 2001-07-27 20:21 Gonzo Rock <[email protected]>
1 sibling, 2 replies; 9+ messages in thread
From: Gonzo Rock @ 2001-07-27 20:21 UTC (permalink / raw)
To: pgsql-general; +Cc: [email protected]
OK... Fair Enough... Good Points indeed y'all.
Well... What about the problem of users trying to Query the Database??
You know... like when using Crystal Reports or something?.
SELECT * from HistoryTable
WHERE PartID = SomeInteger
vs
SELECT * from HistoryTable
WHERE PartNum = 12345636 AND PartRev = C
How are they supposed to know What the PartID is ??
Anyway, that I why I was considering changing... current users always have trouble peering into the database... They don't quite get it.
At 02:31 PM 7/27/01 -0400, Mike Mascari wrote:
>I prefer using unique integer ids generated from sequences rather than
>keys composed of meaningful values.
>
>Advantages:
>
>Client side applications can store/handle the unique integer ids more
>readily than having to deal with composite primary keys composed of
>varying data types. For example, I can stuff the id associated with a
>particular record easily in list boxes, combo boxes, edit controls, etc.
>via SetItemData() or some other appropriate method. Its a bit more
>complicated to track database records via composite keys of something
>like: part no, vendor no, vendor group.
>
>Updating the data doesn't require cascading updates. If you use keys
>with meaning, the referential integrity constraints must support
>cascading updates so if the key changes in the primary table the change
>is cascaded to all referencing tables as well. Earlier versions of most
>databases (Access, Oracle, etc.) only provided cascading deletes under
>the assumption you would be using sequence generated keys.
>
>Downside:
>
>Many queries might require more joins against the primary table to fetch
>the relevant information associated with the numerical id, whereas keys
>composed of solely the values with which they are associated might not
>require the joins, which will speed some applications. I now have some
>queries with 20-way joins. But PostgreSQL provides a way to explicitly
>set the path the planner will choose and so the execution of the query
>is instantaneous. I'm not sure about other databases. In earlier
>versions, I had to denormalize a bit solely for performance reasons.
>
>In the past, I used to use composite keys and switched to the purely
>sequence generated path and don't regret it at all. Of course, you'll
>still have a unique constraint on the what-would-have-been meaningful
>primary key.
>
>Hope that helps,
>
>Mike Mascari
>[email protected]
>
>Gonzo Rock wrote:
>>
>> A Question for those of you who consider yourself crack Database Designers.
>>
>> I am currently moving a large database(100+Tables) into pgSQL... with the intention of deploying against 'any' SQL database in the future. The development side will be rigorously using Standard SQL constructs with no unique/proprietary extensions.
>>
>> My question concerns establishing the relationships.
>>
>> Currently Relationships between tables are established via a Unique Integer ID like this:
>>
>> *=APrimaryKey
>>
>> PartTypes Customer Parts
>> --------- -------- -----
>> PartTypeID CustomerID PartID
>> *PartType *Customer PartTypeID
>> Address CustomerID
>> *PartNumber(2FieldPrimaryKey)
>> *PartRevision(2FieldPrimaryKey)
>> PartName
>>
>>
>> HOWEVER; I have read lots of texts describing the Relational Design should be instead like this:
>>
>> *=APrimaryKey
>>
>> PartTypes Customer Parts
>> --------- -------- -----
>> *PartType *Customer PartType
>> Address *PartNumber(2FieldPrimaryKey)
>> *PartRevison(2FieldPrimaryKey)
>> PartName
>> Customer
>>
>> Both Techniques have a unique foreign key back to the parent tables but one uses No.Meaningful.Info.Integer.Data for the ForeignKey while the second uses Human.Understandable.ForeignKeys
>>
>> Is one recommended over the other??? Sure appreciate the commentary before I get in too deep with all these tables.
>>
>> Thanks!
>
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: RE: [SQL] Database Design Question
@ 2001-07-27 20:24 Ryan Mahoney <[email protected]>
1 sibling, 0 replies; 9+ messages in thread
From: Ryan Mahoney @ 2001-07-27 20:24 UTC (permalink / raw)
To: Gonzo Rock <[email protected]>; pgsql-general; +Cc: [email protected]
SELECT * from HistoryTable
WHERE PartNum = 12345636 AND PartRev = C
Is equal to:
SELECT t1.* from HistoryTable t1, PartTable t2
WHERE t2.PartName = 'airplane' AND t1.PartRev = 'C' AND t2.PartNum = t1.PartNum
You can create these joins for your users, and show them they only need to
swap out the name.
-r
At 01:21 PM 7/27/01 -0700, Gonzo Rock wrote:
>OK... Fair Enough... Good Points indeed y'all.
>
>Well... What about the problem of users trying to Query the Database??
>
>You know... like when using Crystal Reports or something?.
>
>SELECT * from HistoryTable
>WHERE PartID = SomeInteger
>
>vs
>
>SELECT * from HistoryTable
>WHERE PartNum = 12345636 AND PartRev = C
>
>How are they supposed to know What the PartID is ??
>
>Anyway, that I why I was considering changing... current users always have
>trouble peering into the database... They don't quite get it.
>
>
>
>
>At 02:31 PM 7/27/01 -0400, Mike Mascari wrote:
> >I prefer using unique integer ids generated from sequences rather than
> >keys composed of meaningful values.
> >
> >Advantages:
> >
> >Client side applications can store/handle the unique integer ids more
> >readily than having to deal with composite primary keys composed of
> >varying data types. For example, I can stuff the id associated with a
> >particular record easily in list boxes, combo boxes, edit controls, etc.
> >via SetItemData() or some other appropriate method. Its a bit more
> >complicated to track database records via composite keys of something
> >like: part no, vendor no, vendor group.
> >
> >Updating the data doesn't require cascading updates. If you use keys
> >with meaning, the referential integrity constraints must support
> >cascading updates so if the key changes in the primary table the change
> >is cascaded to all referencing tables as well. Earlier versions of most
> >databases (Access, Oracle, etc.) only provided cascading deletes under
> >the assumption you would be using sequence generated keys.
> >
> >Downside:
> >
> >Many queries might require more joins against the primary table to fetch
> >the relevant information associated with the numerical id, whereas keys
> >composed of solely the values with which they are associated might not
> >require the joins, which will speed some applications. I now have some
> >queries with 20-way joins. But PostgreSQL provides a way to explicitly
> >set the path the planner will choose and so the execution of the query
> >is instantaneous. I'm not sure about other databases. In earlier
> >versions, I had to denormalize a bit solely for performance reasons.
> >
> >In the past, I used to use composite keys and switched to the purely
> >sequence generated path and don't regret it at all. Of course, you'll
> >still have a unique constraint on the what-would-have-been meaningful
> >primary key.
> >
> >Hope that helps,
> >
> >Mike Mascari
> >[email protected]
> >
> >Gonzo Rock wrote:
> >>
> >> A Question for those of you who consider yourself crack Database
> Designers.
> >>
> >> I am currently moving a large database(100+Tables) into pgSQL... with
> the intention of deploying against 'any' SQL database in the future. The
> development side will be rigorously using Standard SQL constructs with no
> unique/proprietary extensions.
> >>
> >> My question concerns establishing the relationships.
> >>
> >> Currently Relationships between tables are established via a Unique
> Integer ID like this:
> >>
> >> *=APrimaryKey
> >>
> >> PartTypes Customer Parts
> >> --------- -------- -----
> >> PartTypeID CustomerID PartID
> >> *PartType *Customer PartTypeID
> >> Address CustomerID
> >> *PartNumber(2FieldPrimaryKey)
> >> *PartRevision(2FieldPrimaryKey)
> >> PartName
> >>
> >>
> >> HOWEVER; I have read lots of texts describing the Relational Design
> should be instead like this:
> >>
> >> *=APrimaryKey
> >>
> >> PartTypes Customer Parts
> >> --------- -------- -----
> >> *PartType *Customer PartType
> >> Address *PartNumber(2FieldPrimaryKey)
> >> *PartRevison(2FieldPrimaryKey)
> >> PartName
> >> Customer
> >>
> >> Both Techniques have a unique foreign key back to the parent tables
> but one uses No.Meaningful.Info.Integer.Data for the ForeignKey while the
> second uses Human.Understandable.ForeignKeys
> >>
> >> Is one recommended over the other??? Sure appreciate the commentary
> before I get in too deep with all these tables.
> >>
> >> Thanks!
> >
>
>---------------------------(end of broadcast)---------------------------
>TIP 5: Have you checked our extensive FAQ?
>
>http://www.postgresql.org/users-lounge/docs/faq.html
>
>
>
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^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: RE: [SQL] Database Design Question
@ 2001-07-27 20:39 Mike Mascari <[email protected]>
parent: Gonzo Rock <[email protected]>
1 sibling, 0 replies; 9+ messages in thread
From: Mike Mascari @ 2001-07-27 20:39 UTC (permalink / raw)
To: Gonzo Rock <[email protected]>; +Cc: pgsql-general
Gonzo Rock wrote:
>
> OK... Fair Enough... Good Points indeed y'all.
>
> Well... What about the problem of users trying to Query the Database??
>
> You know... like when using Crystal Reports or something?.
>
> SELECT * from HistoryTable
> WHERE PartID = SomeInteger
>
> vs
>
> SELECT * from HistoryTable
> WHERE PartNum = 12345636 AND PartRev = C
>
> How are they supposed to know What the PartID is ??
>
> Anyway, that I why I was considering changing... current users always have trouble peering into the database... They don't quite get it.
Depending upon the sophistication of your users, you might want to
consider constructing a number of views where the data is pre-joined
(totally denormalized). We essentially do the same thing for both the
reasons you provide as well as for security purposes (row security)
based upon the value of CURRENT_USER.
Hope that helps,
Mike Mascari
[email protected]
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Database Design Question
@ 2001-07-27 20:51 James Orr <[email protected]>
parent: Gonzo Rock <[email protected]>
1 sibling, 0 replies; 9+ messages in thread
From: James Orr @ 2001-07-27 20:51 UTC (permalink / raw)
To: Gonzo Rock <[email protected]>; pgsql-general; +Cc: [email protected]
----- Original Message -----
From: "Gonzo Rock" <[email protected]>
To: <[email protected]>
Cc: <[email protected]>
Sent: Friday, July 27, 2001 4:21 PM
Subject: RE: [SQL] Database Design Question
> OK... Fair Enough... Good Points indeed y'all.
>
> Well... What about the problem of users trying to Query the Database??
>
> You know... like when using Crystal Reports or something?.
>
> SELECT * from HistoryTable
> WHERE PartID = SomeInteger
>
> vs
>
> SELECT * from HistoryTable
> WHERE PartNum = 12345636 AND PartRev = C
>
> How are they supposed to know What the PartID is ??
>
> Anyway, that I why I was considering changing... current users always have
trouble peering into the database... They don't quite get it.
Search conditions don't HAVE to be indexes. And you can have more than one
index. So you could have your primary index on PartID, which would be used
by your applications and another index on PartNum and PartRev if those are
frequently searched fields for crystal reports etc.
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: PostgreSQL to Dia program
@ 2001-07-28 03:14 Justin Clift <[email protected]>
parent: Brent R. Matzelle <[email protected]>
0 siblings, 0 replies; 9+ messages in thread
From: Justin Clift @ 2001-07-28 03:14 UTC (permalink / raw)
To: Brent R. Matzelle <[email protected]>; pgsql-general
Hi Brent,
Thanks for this! I'll put it on my ToDo list for adding.
Good thing I came across your email, about 2/3 to 3/4 of all the
pgsql-general emails I never even get time to read. :(
If you REALLY want to make sure I read something, please CC it to me of
course!
:-)
Regards and best wishes,
Justin Clift
"Brent R. Matzelle" wrote:
>
> Someone just posted a PostgreSQL to Dia automatic diagram
> creation tool. I have not tested it, but if it works it could
> be a huge help.
>
> http://www.zort.ca/postgresql/
>
> Justin, this could definately be a techdocs link.
>
> Brent
>
> __________________________________________________
> Do You Yahoo!?
> Make international calls for as low as $.04/minute with Yahoo! Messenger
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>
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^ permalink raw reply [nested|flat] 9+ messages in thread
end of thread, other threads:[~2001-07-28 03:14 UTC | newest]
Thread overview: 9+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
1970-01-01 00:00 Re: Database Design Question omid omoomi <[email protected]>
2001-07-27 18:03 Database Design Question Gonzo Rock <[email protected]>
2001-07-27 19:06 ` Andre Schnabel <[email protected]>
2001-07-27 20:21 ` PostgreSQL to Dia program Brent R. Matzelle <[email protected]>
2001-07-28 03:14 ` Re: PostgreSQL to Dia program Justin Clift <[email protected]>
2001-07-27 20:21 ` Gonzo Rock <[email protected]>
2001-07-27 20:39 ` Mike Mascari <[email protected]>
2001-07-27 20:51 ` James Orr <[email protected]>
2001-07-27 20:24 ` Ryan Mahoney <[email protected]>
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