Re: performace review
От | Alexander Staubo |
---|---|
Тема | Re: performace review |
Дата | |
Msg-id | A94CC970-36F0-4BD2-A37D-DC4777CEDF8F@purefiction.net обсуждение исходный текст |
Ответ на | Re: performace review ("Brandon Aiken" <BAiken@winemantech.com>) |
Список | pgsql-general |
On Oct 7, 2006, at 23:44 , Brandon Aiken wrote: > I download the db source (inside opencrx-1.9.1- > core.postgresql-8.zip) and executed their three schema files, > dbcreate-indexes.sql, dbcreate-views.sql, dbcreate-tables.sql. > Each of the 118 tables has a three-field composite primary key of > 'PRIMARY KEY (object_rid, object_oid, object_idx)'. object_rid and > object_oid are both VARCHAR(200). There are *no* foreign key > constraints. Each table has between 15 and 50 fields, with 25 > looking about average. To be fair, there are a bunch of indexes, but the number of indexes seems low compared to the number of fields. > Gee, why to table joins take so long? Maybe because a blind monkey > created the schema? Normalized databases do tend to perform > better, so I hear. *De*normalization is the traditional hack to speed up queries, because it reduces the need for joins. Alexander.
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