- Да и да;
- Йерархия на раздели в база знания (една от реализациите);
- Да;
Дефиницията на една от въпросните таблици:
Table "knowledgebase.section"
Column | Type | Modifiers
----------------------------+--------------------------+-----------------------------------------------------------------------------
section_sid | integer | not null default nextval('knowledgebase.section_section_sid_seq'::regclass)
section | character varying | not null
description | character varying |
path | ltree | not null
is_active | boolean | not null default true
role_sid | integer | not null
last_modified_by | integer | not null
creation_datetime | timestamp with time zone | not null default now()
last_modification_datetime | timestamp with time zone | not null default now()
is_expanded | boolean | not null default false
section_idx | tsvector |
Indexes:
"section_sid_pkey" PRIMARY KEY, btree (section_sid)
"section_section_key" UNIQUE, btree (section)
"idxsection_idx" gist (section_idx)
"path_gist_idx" gist (path)
Foreign-key constraints:
"last_modified_by_fkey" FOREIGN KEY (last_modified_by) REFERENCES "user"."role"(role_sid) ON UPDATE CASCADE ON DELETE RESTRICT
"role_sid_fkey" FOREIGN KEY (role_sid) REFERENCES "user"."role"(role_sid) ON UPDATE CASCADE ON DELETE RESTRICT
Triggers:
section_idx_update BEFORE INSERT OR UPDATE ON knowledgebase.section FOR EACH ROW EXECUTE PROCEDURE tsearch2('section_idx', 'section')
Колоната "път" използва първичния ключ като етикет.
Извадка от текущото съдържание на тази таблица (по отношение на първичния ключ и колоната „path“):
section_sid | path
-------------+-------
53 | 34.53
56 | 56
55 | 29.55
35 | 35
54 | 34.54
37 | 30.37
... | ...