Part VII. Internals

Table of Contents

51. Overview of PostgreSQL Internals

51.1. The Path of a Query

51.2. How Connections Are Established

51.3. The Parser Stage

51.4. The PostgreSQL Rule System

51.5. Planner/Optimizer

51.6. Executor

52. System Catalogs

52.1. Overview

52.2. pg_aggregate

52.3. pg_am

52.4. pg_amop

52.5. pg_amproc

52.6. pg_attrdef

52.7. pg_attribute

52.8. pg_authid

52.9. pg_auth_members

52.10. pg_cast

52.11. pg_class

52.12. pg_collation

52.13. pg_constraint

52.14. pg_conversion

52.15. pg_database

52.16. pg_db_role_setting

52.17. pg_default_acl

52.18. pg_depend

52.19. pg_description

52.20. pg_enum

52.21. pg_event_trigger

52.22. pg_extension

52.23. pg_foreign_data_wrapper

52.24. pg_foreign_server

52.25. pg_foreign_table

52.26. pg_index

52.27. pg_inherits

52.28. pg_init_privs

52.29. pg_language

52.30. pg_largeobject

52.31. pg_largeobject_metadata

52.32. pg_namespace

52.33. pg_opclass

52.34. pg_operator

52.35. pg_opfamily

52.36. pg_parameter_acl

52.37. pg_partitioned_table

52.38. pg_policy

52.39. pg_proc

52.40. pg_publication

52.41. pg_publication_namespace

52.42. pg_publication_rel

52.43. pg_range

52.44. pg_replication_origin

52.45. pg_rewrite

52.46. pg_seclabel

52.47. pg_sequence

52.48. pg_shdepend

52.49. pg_shdescription

52.50. pg_shseclabel

52.51. pg_statistic

52.52. pg_statistic_ext

52.53. pg_statistic_ext_data

52.54. pg_subscription

52.55. pg_subscription_rel

52.56. pg_tablespace

52.57. pg_transform

52.58. pg_trigger

52.59. pg_ts_config

52.60. pg_ts_config_map

52.61. pg_ts_dict

52.62. pg_ts_parser

52.63. pg_ts_template

52.64. pg_type

52.65. pg_user_mapping

53. System Views

53.1. Overview

53.2. pg_aios

53.3. pg_available_extensions

53.4. pg_available_extension_versions

53.5. pg_backend_memory_contexts

53.6. pg_config

53.7. pg_cursors

53.8. pg_file_settings

53.9. pg_group

53.10. pg_hba_file_rules

53.11. pg_ident_file_mappings

53.12. pg_indexes

53.13. pg_locks

53.14. pg_matviews

53.15. pg_policies

53.16. pg_prepared_statements

53.17. pg_prepared_xacts

53.18. pg_publication_tables

53.19. pg_replication_origin_status

53.20. pg_replication_slots

53.21. pg_roles

53.22. pg_rules

53.23. pg_seclabels

53.24. pg_sequences

53.25. pg_settings

53.26. pg_shadow

53.27. pg_shmem_allocations

53.28. pg_shmem_allocations_numa

53.29. pg_stats

53.30. pg_stats_ext

53.31. pg_stats_ext_exprs

53.32. pg_tables

53.33. pg_timezone_abbrevs

53.34. pg_timezone_names

53.35. pg_user

53.36. pg_user_mappings

53.37. pg_views

53.38. pg_wait_events

54. Frontend/Backend Protocol

54.1. Overview

54.2. Message Flow

54.3. SASL Authentication

54.4. Streaming Replication Protocol

54.5. Logical Streaming Replication Protocol

54.6. Message Data Types

54.7. Message Formats

54.8. Error and Notice Message Fields

54.9. Logical Replication Message Formats

54.10. Summary of Changes since Protocol 2.0

55. PostgreSQL Coding Conventions

55.1. Formatting

55.2. Reporting Errors Within the Server

55.3. Error Message Style Guide

55.4. Miscellaneous Coding Conventions

56. Native Language Support

56.1. For the Translator

56.2. For the Programmer

57. Writing a Procedural Language Handler

58. Writing a Foreign Data Wrapper

58.1. Foreign Data Wrapper Functions

58.2. Foreign Data Wrapper Callback Routines

58.3. Foreign Data Wrapper Helper Functions

58.4. Foreign Data Wrapper Query Planning

58.5. Row Locking in Foreign Data Wrappers

59. Writing a Table Sampling Method

59.1. Sampling Method Support Functions

60. Writing a Custom Scan Provider

60.1. Creating Custom Scan Paths

60.2. Creating Custom Scan Plans

60.3. Executing Custom Scans

61. Genetic Query Optimizer

61.1. Query Handling as a Complex Optimization Problem

61.2. Genetic Algorithms

61.3. Genetic Query Optimization (GEQO) in PostgreSQL

61.4. Further Reading

62. Table Access Method Interface Definition

63. Index Access Method Interface Definition

63.1. Basic API Structure for Indexes

63.2. Index Access Method Functions

63.3. Index Scanning

63.4. Index Locking Considerations

63.5. Index Uniqueness Checks

63.6. Index Cost Estimation Functions

64. Write Ahead Logging for Extensions

64.1. Generic WAL Records

64.2. Custom WAL Resource Managers

65. Built-in Index Access Methods

65.1. B-Tree Indexes

65.2. GiST Indexes

65.3. SP-GiST Indexes

65.4. GIN Indexes

65.5. BRIN Indexes

65.6. Hash Indexes

66. Database Physical Storage

66.1. Database File Layout

66.2. TOAST

66.3. Free Space Map

66.4. Visibility Map

66.5. The Initialization Fork

66.6. Database Page Layout

66.7. Heap-Only Tuples (HOT)

67. Transaction Processing

67.1. Transactions and Identifiers

67.2. Transactions and Locking

67.3. Subtransactions

67.4. Two-Phase Transactions

68. System Catalog Declarations and Initial Contents

68.1. System Catalog Declaration Rules

68.2. System Catalog Initial Data

68.3. BKI File Format

68.4. BKI Commands

68.5. Structure of the Bootstrap BKI File

68.6. BKI Example

69. How the Planner Uses Statistics

69.1. Row Estimation Examples

69.2. Multivariate Statistics Examples

69.3. Planner Statistics and Security

70. Backup Manifest Format

70.1. Backup Manifest Top-level Object

70.2. Backup Manifest File Object

70.3. Backup Manifest WAL Range Object