PostgreSQL9.2.4 Kernel source Code structure introduction

PostgreSQL source code can be freely available, and its open source protocol allows researchers to arbitrarily modify, here to introduce the source of PostgreSQL and some implementation mechanism. After downloading the PostgreSQL source code and decompression, its first-level directory structure is as follows:

　　　　　　　　　　　　　　

PostgreSQL Source code level structure

Where the Config directory contains some system configuration files. The contrib directory includes some peripheral tools and some experimental development code that are not integrated into the core code. The doc directory is the Help document, written by SGML. SRC is the system core code, other files belong to the compilation and installation related files. SRC directory, each subdirectory and its corresponding contents are as follows:

subdirectory structure under the PostgreSQL source code src Directory

Backend	Database Engine code, also known as background program code.
Bin	Peripheral tools, such as the database Connection tool Psql.
Include	Header file directory.
Interface	External interfaces provided by the system, such as LIBPQ.
Makefiles	Platform-related makefile files.
Pl	Implementation code such as process language pl/postgresqlsql.
Port	Platform compatible processing module.
Template	A compiled script template for different platforms.
Test	Regression test cases and automated test frameworks.
TimeZone	Time zone-related code and data.
Tools	Accessibility tools, such as compiling a version of Windows Script.
Tutorial	An example of some of the examples provided by the system.

The core implementation code of the system is located in the Src\backend directory

Access	The data access layer, which includes the operation of the table data index and the transaction-related code.
Bootstrap	The database initialization module is closely related to the code under SRC\BIN\INITDB
Catalog	The operation-related code for the system table.
Commands	SQL command execution, including vacuum, copy, Alter, and so on.
Executor	SQL statement execution, including the execution of SELECT, INSERT, UPDATE, and DELETE statements.
Foreign	FDW (Foreign Data Wrapper) handles related code
Lib	A common library that contains several common programs.
Libpq	The front-end communication handles the related code.
Main	The system main entry function, which is responsible for transferring control to postmaster or Postgres.
Nodes	Node-related code, which is the storage unit in the query plan.
Optimizer	Query optimization related code, responsible for creating query paths and query plans.
Parser	SQL statement parsing module.
Po	Internationalization (i18n) processing module
Port	Platform compatible processing module.
Postmaster	The main process postmaster related code.
Regex	The regular expression processing module.
Replicati/on	Streaming replicati/on related code.
Rewrite	Rule system module.
Snowball	The word breaker is used to implement full-text retrieval.
Storage	Storage-tier modules, including Storage Manager, buffer management, file management, lock management, and so on.
Tcop	The SQL command Distribution module is responsible for invoking functions in parser, optimizer, executor, and commands.
Tsearch	Full-text retrieval module.
Utils	Some ancillary programs, such as the built-in data types, error reporting, sorting implementation, and other related code.