pg_hint_plan14

This Release
pg_hint_plan14 1.4.3
Date
Status
Stable
Other Releases
Abstract
Query hints in SQL comments
Description
This library adds support for query hints in SQL comments in PostgreSQL 14.
Released By
michaelpq
License
BSD
Resources
Special Files
Tags

Extensions

pg_hint_plan 1.4.3
Query hints in SQL comments

Documentation

description
Description
hint_list
Hint list
errors
Errors
installation
Installation
functional_limitations
Functional limitations
index
pg_hint_plan 1.4
hint_table
The hint table
requirements
requirements
hint_details
Details in hinting
synopsis
Synopsis
uninstallation
Uninstallation

README

Contents

pg_hint_plan 1.4

pg_hint_plan makes it possible to tweak PostgreSQL execution plans using so-called “hints” in SQL comments, like /*+ SeqScan(a) */.

PostgreSQL uses a cost-based optimizer, that uses data statistics, not static rules. The planner (optimizer) estimates costs of each possible execution plans for a SQL statement, then executes the plan with the lowest cost. The planner does its best to select the best execution plan, but it is far from perfect, since it may not count some data properties, like correlation between columns.

For more details, please see the various documentations available in the docs/ directory:

  1. Description
  2. The hint table
  3. Installation
  4. Uninstallation
  5. Details in hinting
  6. Errors
  7. Functional limitations
  8. Requirements
  9. Hints list

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