Wiki / Configuration Parameters
from_collapse_limit
The planner will merge sub-queries into upper queries if the resulting FROM list would have no more than this many items. Smaller values reduce planning time but might yield inferior query plans. The default is eight. For more information see Section 14.3. Setting this value to geqo_threshold or more may trigger use of the GEQO planner, resulting in non-optimal plans. See Section 19.7.3.
English manual coverage begins with PostgreSQL 7.4. Source history and runtime observations have their own recorded version boundaries.
Reading PG 18·Select a recorded version
- boot val
- 8
- category
- Query Tuning / Other Planner Options
- context
- user
- documented
- true
- enumvals
- Unknown
- extra desc
- The planner will merge subqueries into upper queries if the resulting FROM list would have no more than this many items.
- lang
- en
- max val
- 2147483647
- metadata version
- 18
- min val
- 1
- name
- from_collapse_limit
- short desc
- Sets the FROM-list size beyond which subqueries are not collapsed.
- source
- pg-settings-source-snapshot
- unit
- Unknown
- vartype
- integer
Definition PG 18
The planner will merge sub-queries into upper queries if the resulting FROM list would have no more than this many items. Smaller values reduce planning time but might yield inferior query plans. The default is eight. For more information see Section 14.3. Setting this value to geqo_threshold or more may trigger use of the GEQO planner, resulting in non-optimal plans. See Section 19.7.3.
Compare versions
Source references
Full definition and evidence JSON
Definition sources
center · PostgreSQL 18 · wiki-repair-20261023:4d1c1dd655d76fb19d14c3289f4d33d62b503ccad74457fa8bece894f408b39c
Text language: en · wiki-repair-20261023:4d1c1dd655d76fb19d14c3289f4d33d62b503ccad74457fa8bece894f408b39c