[postgis-tickets] [PostGIS] #3344: Unnecessary use of table/possible speed improvement

[PostGIS]

#3344: Unnecessary use of table/possible speed improvement
--------------------------+---------------------------
  Reporter:  postgispaul  |      Owner:  pramsey
      Type:  enhancement  |     Status:  closed
  Priority:  medium       |  Milestone:  PostGIS 2.1.9
 Component:  postgis      |    Version:  2.1.x
Resolution:  wontfix      |   Keywords:
--------------------------+---------------------------
Changes (by robe):

 * status:  new => closed
 * resolution:   => wontfix
 * milestone:   => PostGIS 2.1.9


Comment:

 If there is an issue here, it is more to do with the PostgreSQL query
 planner and little to do with postgis.

 First of all you didn't state which version of PostgreSQL or PostGIS you
 are using.

 How the PostgreSQL planner operates on joins has changed over the years
 and would also I think be dependent on what keys you have in place.  I
 think PostgresQL got smarter around 9.1 with how it handles left joins to
 determine if it has to look at the second table or not.  If names.id isn't
 marked as a primary key in the second table, then it would definitely have
 to treat it as if it would effect the end result.

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3344#comment:1>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.