| From: | PG Doc comments form <noreply(at)postgresql(dot)org> |
|---|---|
| To: | pgsql-docs(at)lists(dot)postgresql(dot)org |
| Cc: | splarv(at)ya(dot)ru |
| Subject: | explanation for random_page_cost is outdated |
| Date: | 2020-02-27 14:48:44 |
| Message-ID: | 158281492445.30439.15446208692175239579@wrigleys.postgresql.org |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-docs |
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/12/runtime-config-query.html
Description:
Explanation for random_page_cost is rather outdated, because it did only for
case of mechanical hdd. But all modern database servers, which I know, made
upon SSD. Do or not do default value for random_page_cost equal to 1 is the
question, but, IMHO, at list in the documentation about random_page_cost
need to add in a speculation about SSD.
It's important because a business programming now is mostly web programming.
Most database is poorly designed by web programmer, tables looked like a
primary key and a huge json (containing all) with large gin index upon it.
Now I am seeing a table with a GIN index 50% of the table size. The database
is on SSD, of cause. With default random_page_cost=4 GIN index don't used
by planner, but with random_page_cost=1 the result may be not excellent, but
acceptable for web programmers.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | PG Doc comments form | 2020-02-27 15:52:36 | thoroughly broken examples on the Dynamic SQL page |
| Previous Message | Laurenz Albe | 2020-02-26 14:03:19 | Re: No docs for interaction of ON DELETE/UPDATE and permissions |