increase full table scan time in docs Explain tutorial

[awoods187]

Andy Woods (awoods187) commented:

@rytaft and I were talking about the Explain guide

The full table scan query returns in 4ms.

SELECT * FROM users WHERE name = 'Cheyenne Smith';
                   id                  | city  |      name      |      address      | credit_card  
+--------------------------------------+-------+----------------+-------------------+-------------+
  e147ae14-7ae1-4800-8000-00000000002c | paris | Cheyenne Smith | 8550 Kelsey Flats | 4374468739   
(1 row)

Time: 4.059ms

This is actually pretty fast! We would both be a bit surprised if anyone really cares that much about a couple of milliseconds. Rebecca pointed out that this example would be more impactful if you change it to >1s getting reduced to ~1ms. Just making the scanned table bigger should have that effect.

Jira Issue: DOC-385

[awoods187]

@rmloveland i'm tagging you here on @jseldess recommendation since this fits developer guide