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VII. Internals

This part contains assorted information that can be of use to PostgreSQL developers.

Table of Contents
42. Overview of PostgreSQL Internals
42.1. The Path of a Query
42.2. How Connections are Established
42.3. The Parser Stage
42.4. The PostgreSQL Rule System
42.5. Planner/Optimizer
42.6. Executor
43. System Catalogs
43.1. Overview
43.2. pg_aggregate
43.3. pg_am
43.4. pg_amop
43.5. pg_amproc
43.6. pg_attrdef
43.7. pg_attribute
43.8. pg_authid
43.9. pg_auth_members
43.10. pg_autovacuum
43.11. pg_cast
43.12. pg_class
43.13. pg_constraint
43.14. pg_conversion
43.15. pg_database
43.16. pg_depend
43.17. pg_description
43.18. pg_index
43.19. pg_inherits
43.20. pg_language
43.21. pg_largeobject
43.22. pg_listener
43.23. pg_namespace
43.24. pg_opclass
43.25. pg_operator
43.26. pg_pltemplate
43.27. pg_proc
43.28. pg_rewrite
43.29. pg_shdepend
43.30. pg_shdescription
43.31. pg_statistic
43.32. pg_tablespace
43.33. pg_trigger
43.34. pg_type
43.35. System Views
43.36. pg_cursors
43.37. pg_group
43.38. pg_indexes
43.39. pg_locks
43.40. pg_prepared_statements
43.41. pg_prepared_xacts
43.42. pg_roles
43.43. pg_rules
43.44. pg_settings
43.45. pg_shadow
43.46. pg_stats
43.47. pg_tables
43.48. pg_timezone_abbrevs
43.49. pg_timezone_names
43.50. pg_user
43.51. pg_views
44. Frontend/Backend Protocol
44.1. Overview
44.2. Message Flow
44.3. Message Data Types
44.4. Message Formats
44.5. Error and Notice Message Fields
44.6. Summary of Changes since Protocol 2.0
45. PostgreSQL Coding Conventions
45.1. Formatting
45.2. Reporting Errors Within the Server
45.3. Error Message Style Guide
46. Native Language Support
46.1. For the Translator
46.2. For the Programmer
47. Writing A Procedural Language Handler
48. Genetic Query Optimizer
48.1. Query Handling as a Complex Optimization Problem
48.2. Genetic Algorithms
48.3. Genetic Query Optimization (GEQO) in PostgreSQL
48.4. Further Reading
49. Index Access Method Interface Definition
49.1. Catalog Entries for Indexes
49.2. Index Access Method Functions
49.3. Index Scanning
49.4. Index Locking Considerations
49.5. Index Uniqueness Checks
49.6. Index Cost Estimation Functions
50. GiST Indexes
50.1. Introduction
50.2. Extensibility
50.3. Implementation
50.4. Examples
50.5. Crash Recovery
51. GIN Indexes
51.1. Introduction
51.2. Extensibility
51.3. Implementation
51.4. GIN tips and tricks
51.5. Limitations
51.6. Examples
52. Database Physical Storage
52.1. Database File Layout
52.2. TOAST
52.3. Database Page Layout
53. BKI Backend Interface
53.1. BKI File Format
53.2. BKI Commands
53.3. Structure of the Bootstrap BKI File
53.4. Example
54. How the Planner Uses Statistics
54.1. Row Estimation Examples