postgreSQL解釋分析函數

Question

我想了解postgresql中的查詢優化，我有一個函數，其中有一些查詢。其中有些是簡單的querys一個用於保存值到一個變量，然後下一個查詢需要這個變量找東西..讓說：

function()... 
select type into t 
from tableA 
where code = a_c; 

select num into n 
from tableB 
where id = t; 
end function... 

等等..如果我想解釋分析整個功能我執行命令explain analyze select function（）;這是做到這一點的正確方法，還是我必須解釋分析函數中的每個查詢，並且如果有的話，用什麼值？

Answer 1

考慮使用auto_explain模塊：

The auto_explain module provides a means for logging execution plans of slow statements automatically, without having to run EXPLAIN by hand. This is especially helpful for tracking down un-optimized queries in large applications.

與auto_explain.log_nested_statements開啓：

auto_explain.log_nested_statements (boolean)

auto_explain.log_nested_statements causes nested statements (statements executed inside a function) to be considered for logging. When it is off, only top-level query plans are logged. This parameter is off by default. Only superusers can change this setting.