Logical vs relational

hi,
There are two notations in logical model (Barker and Backman).
The Backman notation in logical model looks like relational model in look and feel.
I want to know the difference between logical and relational in oracle data modeler.
How can i correlate with design theory like (conceptual, logical, physical) ??
regards

It does depend on how you define conceptual and logical.
I always use Barker notation for conceptual and logical as the diagram does not look like the relational/physical model diagram plus it allows me the option of using box-in-box to represent subtypes and to display relationship verbs phrases on the relationship lines. This helps when reviewing with the business.
For me a conceptual model will only have primary entities without attributes (but occasionally with natural keys), and unresolved many-to-many relationships. For a logical data model I will add all attributes, UIDs, datatypes (domains), null/not null flags, resolved intersection entities for the M:M, and reference/lookup entities.
I prefer the Barker notation because it does not show the inherited attributes from the relationships which helps me remember I am doing an entity relationship model not a database or implementation design. I then can forward engineer the logical to a relational model for Oracle or SQL Server (etc). One thing that forward engineering does is to covert the logical data types to the correct physical data types for the selected database. It also creates the PK and FK constraints that can then be generated into DDL to build the tables. You also have options on how to implement the logical subtypes (single table, separate tables, master table with siblings, etc)

Similar Messages

Views always appear as different when engineering from Logical to Relational

I created some views in my logical model. After I engineer them to relational model, they appear in relational with an exclamation mark near the upper left corner. If I try to generate ddl for them, I get an error (-- ERROR: Invalid View VwTest). I realized that I have to "validate selected views", in order for the eclamation mark to disappear, and then I am able to generate ddl for them. After that, when I engineer from logical to relational again, it always shows me that my views are different. The difference is that in logical, my entities are shown between double quotes ("), while in relational, after the validation, the tables are not between double quotes. Is there a way to overcome this?
Thanks

Hi,
Thanks for reporting this problem. It appears that this is happening when the Entity name contains lower-case letters.
David

Engineering (logical to relational) does not do name translation/variable population as expected

I am using OSDDM 3.3.0.747.
I have set up the following template formats, e.g.
Foreign Key: {table}_FK{seq nr}
Unique Constraint: {table}_UK{seq nr}
When I engineer from logical to relational model, I get generated names like the following:
{TABLE}_FK3
TENANTS_UK{SEQ_NR}
TENANTS_UK{SEQ_NR}v1
How do I stop this from happening?

Hi,
thanks for reporting the problem. I logged a bug for problem related to Unique constraint.
For foreign key - there is no variable {table} in template for FK. You can use {child} or {child abbr} instead.
As workaround for Unique constraint - you can apply naming standards for whole relational model - "Apply Naming standards for Keys and Constraint" in context menu for relational model in browser, or at table level - table dialog
Philip

Column Prefix from Logical to Relational Model

Hi,
is there any option, that data modeler append an prefix (table short name) to a column, when the logical model will be transformed to relational model? (Same behavior as Oracle Designer)
Example:
Logical Model
TABLE: PERSON
TABLE-SHORT: PERS
COLUMN-1: ID
COLUMN-1: NAME
Relational-Model
TABLE: PERSON
COLUMN-1: PERS_ID
COLUMN-2: PERS_NAME
Kind Regards,
Stefan

Thanks for your answer!
This Script is not really working for me, because of our foreign keys.
All our Foreign-Keys are named "ID" (for nummeric column) or "INDEX" (for a varchar column). After the transformation form logical to relational all the foreign-keys are named like "ID1", "ID2", "ID3", "INDEX1", "INDEX2" etc.
There is no way to apply this script before the foreign-keys where added in the tables?
The Second Way is to create a new script for this task.
am i the only one with this problem? :-/

Logical to Relational mapping

Is it possible to define mapping between Logical and Relational objects (Entity->Table, Attribute->Column) manually?

no, it's not possible.
Philip

DM3.0 EA2: Logical Model Relation Cardinality:Source Optional mislabeled?

In logical model, created a 1:N non-identifying relation between 2 entities - Parent and Child. Parent is 1:N with Child. Both entities have a single column primary key - parent_id and child_id respectively. I would like to enforce RI such that a parent may exist with no children, but a child may not exist without a parent.
In the logical model the relation properties, cardinality - I modify the Source Optional and Target Optional checkboxes to achieve my desired result. I first tried checking Target Optional and leaving Source Optional un-checked. I then engineer a physical model and generate DDL for Oracle 11g I get this constraint:
SQL>ALTER TABLE child
2      ADD CONSTRAINT Relation_1 FOREIGN KEY
3      (
4       parent_id
5      )
6      REFERENCES parent
7      (
8       parent_id
9      )
10      ON DELETE SET NULL
11 ;
Table altered.Here's a test case illustrating this isn't quite what I wanted (starting with both tables empty):
SQL>
SQL>
SQL>insert into parent (parent_id) values (1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>insert into child (child_id, parent_id) values (901, 1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>delete from parent;
delete from parent
ERROR at line 1:
ORA-01407: cannot update ("ODS_ETL_OWNER"."CHILD"."PARENT_ID") to NULLIf I have Source Optional checked, and Target Optional not checked, engineer a physical model and generate DDL for Oracle 11g I get this constraint which produces the desired results with my test case:
SQL>ALTER TABLE child
2      ADD CONSTRAINT Relation_1 FOREIGN KEY
3      (
4       parent_id
5      )
6      REFERENCES parent
7      (
8       parent_id
9      )
10 ;
Table altered.
SQL>
SQL>insert into parent (parent_id) values (1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>insert into child (child_id, parent_id) values (901, 1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>delete from parent;
delete from parent
ERROR at line 1:
ORA-02292: integrity constraint (ODS_ETL_OWNER.RELATION_1) violated - child
record foundBut that seems backwards - and the documentation also reads as if it’s backwards. Am I missing something or are the Source Optional and Target Optional checkboxes mislabeled? Should they be Source Manditory and Target Manditory?

I would like to enforce RI such that a parent may exist with no children, but a child may not exist without a parent.You need to set parent as optional and child to be mandatory.
Am I missing something or are the Source Optional and Target Optional checkboxes mislabeled? Should they be Source Manditory and Target Manditory?There is a relationship and two ends of that relationship and you can set for each end whether it's optional or not. And that's seen directly using Barker notations. Source and target optionality place will be swapped on diagram if you use IE notation.
I expected that cardinality part could be more confusing for you because at source end you define cardinality of the target, but it seems you have no problem with that.
Philip

Delete rule from logical to relational model

hello!
I use data modeler Version 3.1.0.700 and I have some problems with delete rule.
I have set delete rule in logical model on every relation (NO ACTION) but when i engineer it to relational there is everything randomized.
How do i change this to be as it is in logical model?
Thank you for your answer in advance!
Grega

as I explained in previous post "delete rule"in logical model is used in only one case:
the setting in logical model is used only when relationship will be transformed into optional foreign key with non mandatory FK columns.Settings in compare/copy options" tab are used to exclude some properties from compare and engineer process.
Philip

New Guy Question about Name Changes from Logical to Relational

Sorry for the "New Guy" question. I am trying to do this the way I wished it worked rather than the way it does.
Lets say I have an Entity named "Current Database" with an Attribute named "Current Database Name". All this is in plan english for the Logical Model. Now when I generate the Relational Model I would like the Table named "CDCD_CURRENT_DB" and the column named "CURRENT_DB_NAME".
I have been working with a Glossary and some other features trying to get this to work. It kind of does but I do not fully get it and I think I am missing out on much of the power of the product. I have been forcing the Nickname "CDCD" (As we call it) and the "Database" to "DB" in the "Preferred Abbreviation" of the Entity.
I am working with v3.3.0.734
Thanks for the help.

Hi Sky13,
it can be done with glossary but it looks to me what you want is not that native to glossary approach.
it's good to look here for basics http://www.oracle.com/technetwork/developer-tools/datamodeler/datamodelernamingstandards-167685.pdf
Example here also could be useful if you want to go with glossary - Re: Data Modeler: Naming
If you want to use preferred abbreviation then it should be CDCD_CURRENT_DB.
For me CDCD_ is just a prefix - you can handle it separately in relational model - on whole model, on subview and in both cases classification types also can be used to determine how objects are prefixed.
You don't want Current to be abbreviated then do not put it in glossary however you need to check "Incomplete modifiers" check box in glossary.
Entity property "Short name" goes to table abbreviation during engineering. There is a transformation script which will prefix table columns with table abbreviation if you need it. And another one can remove the prefix.
You can define plural name in glossary and if entity name is a single word then plural will be used during name translation.
Philip

Propagate a deleted attribute from Logical to Relational

SQL Developer Data Modeler 4.0.0.825
Hi. From what I gather from the manual, when we delete an attribute from an entity in the Logical model, then Engineer the Relational model, the change should be detected and allow up to decide how the chage is handled in the "Synchronization of Deleted Objects" table of the Engineer to Relational wizard.
But the deletion is not showing in "Synchronization of Deleted Objects" and it does not get deleted in the Relational Model.
Here's what I am doing.
Create the "Library" model in the SQL Developer Data Modeler tutorial
Engineer a Relational Model
Add a new attribute "Date of Birth" to the Patrons entity in the Logical
Re-Engineer the Relational (new column is created)
Delete "Date of Birth" from Patrons in the Logical model
Re-engineer Relational
There are no little "change" icons in the comparison screen - it looks like there are no changes at all
Nothing appears in the Synchronization of Deleted Objects tab
When I click "Engineer", there Date_of_Birth column is not deleted from the Relational model
Am I doing something wrong?
If I reverse engineer from Relational back to Logical, it DOES identify the Date_of_Birth column as a difference and it wants to copy it back to the Logical.

Hi Ross,
you need to download DM 4.0 production release (4.0.0.833) - it should work there.
Philip

Unable to forward engineer logical to relational (no apparent error)

SQL Developer 3.0.03, rpm install onto Fedora 13 using the embedded data modeling feature.
The logical model has engineered before, but I messed around with the relational (closed it, opened it, deleted, and recreated "relational_1") model and now when I press ">>" button, nothing appears to happen. I see no errors in the messages (and the Preferences log stuff doesn't appear to work properly as I never get a log in the specified location) nor does editing logging.conf appear to alter what is shown anywhere.
Anyone have this issue and know how to resolve it?

Hi,
Check this Re: Engineer to Relational does nothing DM3 Production
It might help you.
For the log file try to set path in Preferences to /sqldeveloper/sqldeveloper/extensions/oracle.datamodeler/log
That's the default directory.

Engineering to and from logical and relational models

I have tried to modify a logical model entity by adding an attribute or two, tried to engineer to the associated relational model, only to have the engineering process create a brand new table rather than adding the new column or two to the existing table.
Creating the column in the table first and engineering back to the logical model didn't appear to do anything, although I might have missed a new logical entity.
Is this how the product is supposed to work?

Hello,
I'm sorry but your steps are not evident for me.How it works - you can start from table or entity, it doesn't matter which one is first you should be able to synchronize changes.
Let's assume you have two relational models RM1 and RM2 and table TABLE_1 in RM1. if you engineer RM1 to logical model then entity will be created that corresponds to TABLE_1 in RM1 (and it will be named TABLE_1 if you don't use glossary that provides replacement of TABLE with something else).
You can add attribute to entity and engineer logical model to other relational model (RM2) - new table will be created in RM2.
Add one more attribute to entity and engineer to RM1 - two attributes will appear showing that two new columns can be created - they are not selected and you have to select them if you want columns to be created.
You'll get only one new attribute (column) if you engineer to RM2 - the first added attributed is already there as column.
Of course you can add columns in tables and can synchronize them with entity in logical model.
Philip

SQL Datamodeler: Logical datamodel: Relation transferable

Hello,
Is it possible to define a relationship in the logcal model as being (non )transferable?
Regards Erik

Hello Erik,
such property is supported for foreign keys in relational model. Enhancement request is created to support it in logical model.
Best regards,
Philip

Data Modeler 3.0 EA1 - Logical= Attributes & Relational= Columns missing

Hi,
I imported Modeler 2.0 design into Modeler 3.0 EA1 and discovered that LOGICAL=>ATTRIBUTES and RELATIONAL=>COLUMNS options are no longer displayed.
Were these options removed from this new version or is my installation broken?
Thanks
Chiedu

Hi Chiedu,
they are removed. Your version is ok - at least for that :).
Philip

Pb to create a logical component related to note 1505281

Hello,
I would like to create a new logical component in order to implement Note 1505281.
When I do smsy -> System group and logical component -> create logical component,
I set:
Logical Component: SAP ERP 6.0
Product: SAP ECC
Product version: SAP ECC 6
Main instance: SAP ECC Server
Name: SAP ERP 6.0
When I click on the green tick I get: Do not use any special characters.
Would you know why?
Thanks in advance for your answer.

Hello,
I have succeded by changing my old ERP (2004) logical component.
Regards,

Anyone got a 3ghz yet? (Logic Pro Related)

Greetings all,
Has anyone got a 3ghz Mac Pro yet? and if so, how's Logic Pro, Reason and Audio Interfaces behaving with you?
Getting ready to order one of them bad boys, just want to know if there's anything I should be aware of before I take the plunge. Thanks in advance.
LGK
Power Mac G5 DP 2.5Ghz Mac OS X (10.4.7) 5GB RAM - 500GB HD

Hey LGK yes me! & it does burn! mind you i have to admit I've had about 5 crashes in logic only when rewired to LIVE 5.2 UB
and I just had to trash logic prefrence file as wouldent load! (1st time)
the CPU distrubition is not perfect (waiting.... and waiting... 10.5)
havent got reason intstalled yet
and dont forget about Universal Audio Units.... theres not too many (espcially free ones) I have a copy of NI Komplete 3 & it runs great under rosetta BUT I want it all in logic as AU plugins! where the heck is the converter hahaha
If anyone has any info on universal AUs pleeeasee let me know!!!
Waiting on the mac pro over the Quad G5 was hard but i only have more waiting.
good luck!
sam

Logical vs relational

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