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Thread: What does 'schema' mean ?

What does 'schema' mean ?

From
Joao Miguel Ferreira
Date:
Hello again,

thx very much for all the previous feedback....

here's another one: what do database people mean by 'schema' ?

jmf

Re: What does 'schema' mean ?

From
Neil Saunders
Date:
http://www.webopedia.com/TERM/S/schema.html:

Pronounce skee-ma, the structure of a database system, described in a
formal language supported by the database management system (DBMS). In
a relational database, the schema defines the tables, the fields in
each table, and the relationships between fields and tables.

Schemas are generally stored in a data dictionary. Although a schema
is defined in text database language, the term is often used to refer
to a graphical depiction of the database structure.

So basically, the design of your database.

HTH,

Neil.

On 1/9/06, Joao Miguel Ferreira <jmf@estg.ipvc.pt> wrote:
> Hello again,
>
> thx very much for all the previous feedback....
>
> here's another one: what do database people mean by 'schema' ?
>
> jmf
>
>
>
>
> ---------------------------(end of broadcast)---------------------------
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Re: What does 'schema' mean ?

From
"A. Kretschmer"
Date:
am  09.01.2006, um 15:39:03 -0500 mailte Joao Miguel Ferreira folgendes:
> Hello again,
>
> thx very much for all the previous feedback....
>
> here's another one: what do database people mean by 'schema' ?

practical that, what in MySQL called 'Database'. You should use schemas
to separate different applications.


HTH, Andreas
--
Andreas Kretschmer    (Kontakt: siehe Header)
Heynitz:  035242/47212,      D1: 0160/7141639
GnuPG-ID 0x3FFF606C http://wwwkeys.de.pgp.net
 ===    Schollglas Unternehmensgruppe    ===

Re: What does 'schema' mean ?

From
Tom Lane
Date:
Neil Saunders <n.j.saunders@gmail.com> writes:
>> here's another one: what do database people mean by 'schema' ?

> So basically, the design of your database.

Just to confuse matters, the SQL language also uses SCHEMA to mean
a specific kind of database entity, which probably would have been
better called NAMESPACE.

Q: What does your database schema look like?
A: There are forty-two tables in four schemas, containing ...

People also speak of the schema of an individual table, for example,
meaning the set of columns it has, what indexes it has, and so on
(more or less the info that psql's "\d table" command shows).

The word's a tad overloaded, but all of these usages seem to be
pretty firmly established.

            regards, tom lane

Re: What does 'schema' mean ?

From
Frank Bax
Date:
At 03:39 PM 1/9/06, Joao Miguel Ferreira wrote:
>here's another one: what do database people mean by 'schema' ?


I was thinking about asking the same question, because PGSQL appears to
have two things called 'schema'.  The pg_dump (ver 7.4.3) man page says:
         -n (--schema) appears to say 'namespace' and 'schema' are
synonymous - "Dump contents of 'schema'".
         -s option appears to say 'data definition' and 'schema' are
synonymous - "dump only the schema (data definitions), no data".

So, in summary, a schema (namespace) contains a schema (data definitions)?

Frank

Re: What does 'schema' mean ?

From
Date:
>> thx very much for all the previous feedback....
>>
>> here's another one: what do database people mean by 'schema' ?
>
> practical that, what in MySQL called 'Database'. You should use schemas
> to separate different applications.

huh? i rather use different dbs on pgsql for different applications, and
different schemas for grouping the various tables/functionalities for
specific parts of the database...

- thomas