Horton

Re: Add A Glossary

Jürgen Purtz <juergen@purtz.de>

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From: Jürgen Purtz <juergen@purtz.de>
To: Corey Huinker <corey.huinker@gmail.com>
Cc: Roger Harkavy <rogerharkavy@gmail.com>, pgsql-hackers@postgresql.org, Fabien COELHO <coelho@cri.ensmp.fr>, Michael Paquier <michael@paquier.xyz>
Date: 2020-03-13T04:18:40Z
Lists: pgsql-hackers, pgsql-docs 
> The statement that names of schema objects are unique isn't 
> /strictly/ true, just /mostly/ true. Take the case of a unique 
> constraints. 

Concerning CONSTRAINTS you are right. Constraints seems to be an exception:

  * Their name belongs to a schema, but are not necessarily unique
    within this context:
    https://www.postgresql.org/docs/current/catalog-pg-constraint.html.
  * There is a UNIQUE index within the system catalog pg_constraints:
    "pg_constraint_conrelid_contypid_conname_index" UNIQUE, btree
    (conrelid, contypid, conname), which expresses that names are unique
    within the context of a table/constraint-type. Nevertheless tests
    have shown that some stronger restrictions exists across
    table-boarders (,which seems to be implemented in CREATE statements
    - or as a consequence of your mentioned correlation between
    constraint and index ?).

I hope that there are no more such exception to the global rule 'object 
names in a schema are unique': 
https://www.postgresql.org/docs/current/sql-createschema.html

This facts must be mentioned as a short note in glossary and in more 
detail in the later patch about the architecture.

J. Purtz

Commits

  1. Glossary: Add term "base backup"

  2. Minor glossary tweaks

  3. Adjust some glossary terms

  4. Fix more typos and grammar problems in the glossary

  5. Review of the glossary

  6. Add a glossary to the documentation