[postgis-tickets] [PostGIS] #4362: generic plan slowness

[PostGIS]

#4362: generic plan slowness
----------------------------+---------------------------
 Reporter:  Taro Matsuzawa  |      Owner:  pramsey
     Type:  defect          |     Status:  new
 Priority:  medium          |  Milestone:  PostGIS 2.5.3
Component:  postgis         |    Version:  trunk
 Keywords:                  |
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 When we use "PREPARE" AND "EXECUTE" (https://www.postgresql.org/docs/9.6
 /sql-prepare.html), sometime generic plan will be slowness.

 I find this issue with openmaptiles
 project(https://github.com/openmaptiles/postgis/pull/13). I put my report
 in my
 gist(https://gist.github.com/smellman/060ee2693589e070deacc1715f4642f3
 #file-openmaptiles_postserve_postgis2-5-1_research-txt). First 5times
 queries are fast but after queries are slow in same session. The problem
 happen in 2.4.0, 2.4.7, 2.5.1, 2.5.2 and trunk.

 Also this issue come from fixes #3731 . I built and ran with my revert
 commit(https://github.com/smellman/postgis-1/commit/7e2cbaf8e56f15bbdb1f7b49511669c91fbb8d25),
 the slowness issue seem fixed. But it will raise #3731 problem again.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4362>
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