Re: Schema's vs Single Database with prefix on tables

I agree with Evan. Schemas are a great way to stay organized.
Additionally there is lots of flexibility with pgdump creating backups of
schemas to create dev and test environments. I would carefully design and
plan a central schema that has an established reference tables, this will
make your life and developer’s life much easier for doing reporting across
all or a subset of domains. The alias you choose for each domain can be in
a reference table and used when creating public synonyms for individual
schema tables. The sooner you have this standardized the better.
Your central schema can own functions, global views, types and so forth.
When a new domain is added you have a simple to
Add to database without impacting ongoing operations

On Sun, Sep 9, 2018 at 22:13 Evan Bauer <evanbauer(at)mac(dot)com> wrote:

> Joao,
>
> I strongly agree with Tim’s recommendation to create a schema for each
> “domain.” In addition to the reasons below, the prefix model would seem to
> condemn your programs and programmers to using dynamic SQL to construct
> your business logic in a manner that would work for any domain, as the
> table names for each SQL statement would vary based on the domain.
>
> Schemas are a solid approach to multi-domain design, they should work well
> for you.
>
> Cheers,
>
> - Evan
>
> Evan Bauer
> eb(at)evanbauer(dot)com
> +1 646 641 2973
> Skype: evanbauer
>
>
> On Sep 9, 2018, at 18:02, Tim Cross <theophilusx(at)gmail(dot)com> wrote:
>
>
> Joao Ribeiro <joao(dot)ribeiro(at)foursource(dot)pt> writes:
>
> Hello,
>
> We are using Postgres and we are with a issue. We have splited our tables
> by domain and
> each domain has a separated database, but we are trying to change it to a
> single database
> model. We have two options, create the same database in a single schema
> and add a prefix
> on each database domain or create a schema for each database (we have
> about 15
> different models). In this approach we still want to do some joins and
> other queries cross
> schema, but we don’t know what would be the best approach :) Could you
> help us to know
> what would be the best approach ?
>
> * having just one database with one schema and all domain databases with a
> prefix
> * having a schema for each domain (15 domains) with the domain databases
> (+/ 20 tables)
> (knowing that we do cross schema queries)
>
> _____
>
>
> It is probably just a matter of taste to some extent. I personally would
> favour separate schemas over tables in same schema with prefixes because
> I think that gives you more flexibility i.e. easier to select all the
> data associated with a domain as it is all in one schema. I also think
> it is easier to define security roles on a per schema basis rather than
> complex roles in the same schema, especially if you add new objects
> etc. Auditing is also less complex.
>
> There are no issues with cross-schema queries/joins etc apart from
> having to include the schema name in the query. Some people don't like
> this because you have to type more and have a longer search_path, but if
> the alternative is table prefixes, the amount of typing is similar
> anyway.
>
> Essentially, the schema gives you a predefined unit which many
> tools/commands understand. If everything is in the same schema, then you
> will often need to replicate some level of this functionality yourself
> and then ensure it is maintained. Extent to which this has an impact
> really depends on your use case.
>
> Tim
>
> --
> Tim Cross
>
>
>