[SQL] 錯誤訊息 8623

一大早開 mail 就被嚇到，這是甚麼錯誤訊息，Orz

錯誤訊息

The query processor ran out of internal resources and could not produce a query plan. This is a rare event and only expected for extremely complex queries or queries that reference a very large number of tables or partitions. Please simplify the query. If you believe you have received this message in error, contact Customer Support Services for more information.

根據這篇官方文章  FIX: Error message when you run a complex query after you install Cumulative Update 3 or Cumulative Update 4 for SQL Server 2005 Service Pack 2: "The query processor ran out of internal resources and could not produce a query plan" ，是說明 SP2 的 CU3 或 CU4 就已經修正，我們是 SP4 了，Orz

2009 年的 Connect 回報，The query processor ran out of internal resources and could not produce a query plan with WHERE in and several thousand values，根據官方回答，看來是要無解啦

後來詢問同事（就兩個人寫 ERP，很容易找出兇手，哈），同事有提到是用 UNION ALL 去串接資料產生這個錯誤訊息，發現後就馬上改掉 T-SQL 語法，雖然跟查到資料的方向都不太一樣，但看來這個 Error 應該是不會在出現才對

參考資料
• FIX: Error message when you run a complex query after you install Cumulative Update 3 or Cumulative Update 4 for SQL Server 2005 Service Pack 2: "The query processor ran out of internal resources and could not produce a query plan"
  
• The query processor ran out of internal resources and could not produce a query plan with WHERE in and several thousand values
  
• Using Server Trace to Identify 8623 Errors => 這篇提及是 IN (...) 太多參數造成的