Introduction
There are many sources of advice available on how to tune database systems and applications. Articles like DB2 Tuning Tips for OLTP Applications, previously published on the IBM® DB2® Developer Domain, provide advice on topics ranging from tablespace and index design to memory allocation for buffer pools, exploiting transaction and data parallelism and analyzing query plans. These topics are the ABCs of performance tuning.
However, specific advice on how to organize the logic in the stored procedures themselves with an eye on performance is not that common. That is the kind of advice I provide in this article. Even though the article focuses on SQL procedures, most of the information provided here is applicable to SQL logic embedded in applications or in stored procedures written in other languages


簡介
有關(guān)如何調(diào)優(yōu)數(shù)據(jù)庫系統(tǒng)和應(yīng)用程序的好的建議的來源有很多。比如OLTP應(yīng)用程序的DB2調(diào)優(yōu)技巧(以前在 IBM® DB2® 開發(fā)者園地上發(fā)表)之類的文章通過使用事務(wù)和數(shù)據(jù)并行性以及分析查詢方案，給出了從表空間和索引設(shè)計(jì)到緩沖池的內(nèi)存分配等方面的建議。這些方面的內(nèi)容是性能調(diào)優(yōu)的基礎(chǔ)知識(shí)。
但是，有關(guān)如何組織存儲(chǔ)過程自身中的邏輯并著眼于其性能的專門建議卻并不多見。本文就提供了這樣一種建議。盡管本文著重于介紹 SQL 過程，但是這里所提供的大多數(shù)信息同樣適用于用其它語言編寫的在應(yīng)用程序中或存儲(chǔ)過程中嵌入的 SQL 邏輯。