I've been searching around and I'd like to know if anyone can
recommend a decent tool to generate a Database Schema Diagram from an
Oracle DB. I have an existing database that is very large and complex
so generating a visual to explain it's current tables and their
relationships would help a lot of people out.

Free and open source tools preferred but I might be willing to use
something else if the tools is good and highly recommended.

Thanks

On Sep 18, 1:58*pm, Spiff McClure <sardonicstuffedti... (AT) gmail (DOT) com>
wrote:
I use Aqua Data Studio as a sql client and it has a useful diagram
generator. They do have a 30 day trial so you can try it out. I've
used this to generate diagrams and works ok. I'm not a picky and heavy
weight user so YMMV.
HTH,
Sashi

Sashi schreef:
Oracle SQL Developer Data Modeler?

Shakespeare

Shakespeare (whatsin (AT) xs4all (DOT) nl) wrote:
: Sashi schreef:
: > On Sep 18, 1:58 pm, Spiff McClure <sardonicstuffedti... (AT) gmail (DOT) com>
: > wrote:
: >> I've been searching around and I'd like to know if anyone can
: >> recommend a decent tool to generate a Database Schema Diagram from an
: >> Oracle DB. I have an existing database that is very large and complex
: >> so generating a visual to explain it's current tables and their
: >> relationships would help a lot of people out.
: >>
: >> Free and open source tools preferred but I might be willing to use
: >> something else if the tools is good and highly recommended.
: >>
: >> Thanks
: >
: > I use Aqua Data Studio as a sql client and it has a useful diagram
: > generator. They do have a 30 day trial so you can try it out. I've
: > used this to generate diagrams and works ok. I'm not a picky and heavy
: > weight user so YMMV.
: > HTH,
: > Sashi

: Oracle SQL Developer Data Modeler?

Graphviz to do the graphing.

The details for the graphing statements can be extracted from tables such
as USER_CONS_COLUMNS. The graphviz dot language is extremely simple, you
can get a basic graph with statements such as
DEPARTMENTS -> EMPLOYEES ;
DEPARTMENTS -> LOCATIONS ;
EMPLOYEES -> DEPARTMENTS ;

The "record" format is more involved, but can make nodes that look pretty
much like a regular ERD.

Shakespeare schreef:
Sorry, correction. That one is not free.. $3000 per seat ;-(
There must be cheaper tools around for just diagramming.

Shakespeare

yf110 (AT) vtn1 (DOT) victoria.tc.ca (Malcolm Dew-Jones) writes:

This is what I tend to use as well. In addition, there is a little
(perl?) script out there called sqlFairy which will generate the
graphviz 'dot' files from the database or from an sql script that
defines the tables (such as the ones some tools will export). I've found
it works pretty well, but some forms that are valid to Oracle are not
picked up by the script. For example

CREATE TABLE taba (
id NOT NULL CONSTRAINT taba_id_fk
REFERENCES parent_a(id)
....
);

won't work, but

CREATE TABLE taba (
id NUMBER(7( NOT NULL CONSTRAINT taba_id_fk
REFERENCES parent_a(id)
....
);

will work, yet both are legal (though possibly questionable) syntax.

The sqlfairy script uses perl DBI to query the database directly, so you
need DBD:Oracle to get it to work if you don't have sql scripts that
define the database structure.

The extent to which you get good rsults with this tool depends a lot on
how good the database design is. If column names are used in a
consistent manner and you have good constraint definitions, its pretty
good. Initial output from graphviz can need a bit of tweaking and you
may need to try the different graphing algorithms it uses to get a
really good diagrom.

My experience however is that nearly all graphing solutions tend to
break down pretty quickly once you have a moderate to complex schema to
work with. However, I find this to be one of the real strengths of
graphviz - you can easily edit the dot files and even break up the
diagrom into smaller 'chunks' that don't require a printer capable of
printing on pages that are larger than some countries!

Tim



--
tcross (at) rapttech dot com dot au

Spiff McClure wrote:
DBDesigner4 ?