Part VII. Internals

This part contains assorted information that might be of use to Postgres Pro developers.

Table of Contents

52. Overview of Postgres Pro Internals
52.1. The Path of a Query
52.2. How Connections Are Established
52.3. The Parser Stage
52.4. The Postgres Pro Rule System
52.5. Planner/Optimizer
52.6. Executor
53. System Catalogs
53.1. Overview
53.2. pg_aggregate
53.3. pg_am
53.4. pg_amop
53.5. pg_amproc
53.6. pg_attrdef
53.7. pg_attribute
53.8. pg_authid
53.9. pg_auth_members
53.10. pg_cast
53.11. pg_class
53.12. pg_collation
53.13. pg_constraint
53.14. pg_conversion
53.15. pg_database
53.16. pg_db_role_setting
53.17. pg_default_acl
53.18. pg_depend
53.19. pg_description
53.20. pg_enum
53.21. pg_event_trigger
53.22. pg_extension
53.23. pg_foreign_data_wrapper
53.24. pg_foreign_server
53.25. pg_foreign_table
53.26. pg_index
53.27. pg_inherits
53.28. pg_init_privs
53.29. pg_language
53.30. pg_largeobject
53.31. pg_largeobject_metadata
53.32. pg_namespace
53.33. pg_opclass
53.34. pg_operator
53.35. pg_opfamily
53.36. pg_parameter_acl
53.37. pg_partitioned_table
53.38. pg_policy
53.39. pg_proc
53.40. pg_profile
53.41. pg_publication
53.42. pg_publication_namespace
53.43. pg_publication_rel
53.44. pg_range
53.45. pg_replication_origin
53.46. pg_rewrite
53.47. pg_role_password
53.48. pg_seclabel
53.49. pg_sequence
53.50. pg_shdepend
53.51. pg_shdescription
53.52. pg_shseclabel
53.53. pg_statistic
53.54. pg_statistic_ext
53.55. pg_statistic_ext_data
53.56. pg_subscription
53.57. pg_subscription_rel
53.58. pg_tablespace
53.59. pg_transform
53.60. pg_trigger
53.61. pg_ts_config
53.62. pg_ts_config_map
53.63. pg_ts_dict
53.64. pg_ts_parser
53.65. pg_ts_template
53.66. pg_type
53.67. pg_user_mapping
54. System Views
54.1. Overview
54.2. pg_available_extensions
54.3. pg_available_extension_versions
54.4. pg_backend_memory_contexts
54.5. pg_config
54.6. pg_cursors
54.7. pg_file_settings
54.8. pg_group
54.9. pg_hba_file_rules
54.10. pg_ident_file_mappings
54.11. pg_indexes
54.12. pg_locks
54.13. pg_matviews
54.14. pg_policies
54.15. pg_prepared_statements
54.16. pg_autoprepared_statements
54.17. pg_prepared_xacts
54.18. pg_publication_tables
54.19. pg_replication_origin_status
54.20. pg_replication_slots
54.21. pg_roles
54.22. pg_rules
54.23. pg_seclabels
54.24. pg_sequences
54.25. pg_settings
54.26. pg_shadow
54.27. pg_shmem_allocations
54.28. pg_stats
54.29. pg_stats_ext
54.30. pg_stats_ext_exprs
54.31. pg_stats_vacuum_database
54.32. pg_stats_vacuum_indexes
54.33. pg_stats_vacuum_tables
54.34. pg_tables
54.35. pg_timezone_abbrevs
54.36. pg_timezone_names
54.37. pg_user
54.38. pg_user_mappings
54.39. pg_views
54.40. pg_wait_events
55. Frontend/Backend Protocol
55.1. Overview
55.2. Message Flow
55.3. SASL Authentication
55.4. Streaming Replication Protocol
55.5. Logical Streaming Replication Protocol
55.6. Message Data Types
55.7. Message Formats
55.8. Error and Notice Message Fields
55.9. Logical Replication Message Formats
55.10. Summary of Changes since Protocol 2.0
56. Writing a Procedural Language Handler
57. Writing a Foreign Data Wrapper
57.1. Foreign Data Wrapper Functions
57.2. Foreign Data Wrapper Callback Routines
57.3. Foreign Data Wrapper Helper Functions
57.4. Foreign Data Wrapper Query Planning
57.5. Row Locking in Foreign Data Wrappers
58. Writing a Table Sampling Method
58.1. Sampling Method Support Functions
59. Writing a Custom Scan Provider
59.1. Creating Custom Scan Paths
59.2. Creating Custom Scan Plans
59.3. Executing Custom Scans
60. Genetic Query Optimizer
60.1. Query Handling as a Complex Optimization Problem
60.2. Genetic Algorithms
60.3. Genetic Query Optimization (GEQO) in Postgres Pro
60.4. Further Reading
61. Table Access Method Interface Definition
62. Index Access Method Interface Definition
62.1. Basic API Structure for Indexes
62.2. Index Access Method Functions
62.3. Index Scanning
62.4. Index Locking Considerations
62.5. Index Uniqueness Checks
62.6. Index Cost Estimation Functions
63. Write Ahead Logging for Extensions
63.1. Generic WAL Records
63.2. Custom WAL Resource Managers
64. Built-in Index Access Methods
64.1. B-Tree Indexes
64.2. GiST Indexes
64.3. SP-GiST Indexes
64.4. GIN Indexes
64.5. BRIN Indexes
64.6. Hash Indexes
65. Database Physical Storage
65.1. Database File Layout
65.2. TOAST
65.3. Free Space Map
65.4. Visibility Map
65.5. The Initialization Fork
65.6. Database Page Layout
65.7. Heap-Only Tuples (HOT)
66. Transaction Processing
66.1. Transactions and Identifiers
66.2. Transactions and Locking
66.3. Subtransactions
66.4. Two-Phase Transactions
67. How the Planner Uses Statistics
67.1. Row Estimation Examples
67.2. Multivariate Statistics Examples
67.3. Planner Statistics and Security
68. Adaptive Query Execution
68.1. How It Works
69. Backup Manifest Format
69.1. Backup Manifest Top-level Object
69.2. Backup Manifest File Object
69.3. Backup Manifest WAL Range Object