[PostGIS] #5990: Adding 2 lines to Postgis topology takes 2 hours in a production line we have

[PostGIS]

#5990: Adding 2 lines to Postgis topology takes 2 hours in a production line we
have
--------------------------------+---------------------------
  Reporter:  Lars Aksel Opsahl  |      Owner:  strk
      Type:  enhancement        |     Status:  reopened
  Priority:  medium             |  Milestone:  PostGIS 3.6.1
 Component:  topology           |    Version:  3.6.x
Resolution:                     |   Keywords:  performance
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Changes (by strk):

 * keywords:   => performance

Comment:

 Replying to [comment:8 Lars Aksel Opsahl]:
 > Is this how snapping works today in Topology ?
 > The first line is added with no changes because there are no lines to
 snap to and do not depend on tolerance settings.
 > The second line is then added by using
 ST_Snap(line1,topology.edge,1e-07) because there is existing edge close by
 to snapto when calling addLineString with tolerance 1e-07.

 Yes, this is how snapping works today in PostGIS Topology.

 But we always only snap against *vertices* (not "lines"). This is what
 ST_Snap does.

 The problem of frequent updates is a known one and is already ticketed in
 #2993

 A methodology recommendation: when doing research is better to use a
 mailing list thread rather than a trac ticket.

 I'm writing this before trying your input, will do now.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5990#comment:11>
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