PostgreSQL的C++擴展開發指南

PostgreSQL是一個功能強大的開源關系型數據庫管理系統，它支持自定義擴展，以便用戶可以根據自己的需求擴展其功能

1. 了解PostgreSQL擴展的基本概念 在開始開發之前，了解PostgreSQL擴展的基本概念非常重要。擴展是一組C語言函數、數據類型、操作符等，它們可以添加到PostgreSQL中以滿足特定應用程序的需求。擴展可以動態加載和卸載，而無需重新啟動數據庫服務器。

2. 安裝PostgreSQL開發庫 要開發PostgreSQL擴展，您需要安裝PostgreSQL開發庫。這些庫包含了PostgreSQL的內部結構和函數，以及用于構建擴展的工具和頭文件。在Debian/Ubuntu系統上，可以使用以下命令安裝：

   sudo apt-get install libpq-dev
   

   在CentOS/RHEL系統上，可以使用以下命令安裝：

   sudo yum install postgresql-devel
   

3. 創建一個新的擴展 要創建一個新的擴展，您需要創建一個目錄，其中包含擴展的源代碼和配置文件。以下是一個簡單的示例：

   mkdir my_extension
   cd my_extension
   mkdir -p my_extension/src
   touch my_extension/my_extension.control
   touch my_extension/src/my_extension.c
   

4. 編寫擴展的源代碼 在my_extension/src/my_extension.c文件中，編寫您的C語言函數和數據類型。例如，以下代碼定義了一個名為my_new_function的新函數：

   #include "postgres.h"
   #include "utils/syscall.h"
   
   

PG_MODULE_MAGIC;

Datum my_new_function(PG_FUNCTION_ARGS) { // Your function implementation here }

PG_FUNCTION_INFO_V1(my_new_function);

5. 創建擴展的配置文件
在`my_extension`目錄中創建一個名為`my_extension.control`的文件，其中包含有關擴展的信息。以下是一個簡單的示例：

Name: my_extension Version: 1.0 Description: A simple example extension Author: Your Name License: PostgreSQL

Modules:

• my_extension

Dependencies:

• postgres

6. 編譯擴展
使用`pg_regress`工具編譯和測試您的擴展。首先，安裝`pg_regress`：

sudo apt-get install pg_regress

然后，運行以下命令以創建一個測試數據庫并安裝您的擴展：

pg_regress createdb my_test_db pg_regress initdb --db=my_test_db pg_regress test my_test_db

如果一切正常，您將在輸出中看到類似于以下的成功消息：

test my_test_db Creating my_test_db Creating superuser connection Creating schema public Creating extension my_extension Creating table my_table Creating function my_new_function() Creating sequence my_sequence Creating trigger my_trigger Creating index my_index Creating operator family my_opfamily for access method hash Creating operator my_operator using my_opfamily Creating default value for my_column Creating check constraint my_check_constraint on my_table Creating foreign key constraint my_foreign_key_constraint on my_table Creating table my_table_copy Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_opfamily for access method hash in schema public Creating operator my_operator using my_opfamily in schema public Creating default value for my_column in schema public Creating check constraint my_check_constraint on my_table in schema public Creating foreign key constraint my_foreign_key_constraint on my_table in schema public Creating table my_table_copy in schema public Creating function my_new_function() in schema public Creating sequence my_sequence in schema public Creating trigger my_trigger in schema public Creating index my_index in schema public Creating operator family my_