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mojunbin：
这个不能不顶。
《Pro Oracle SQL》 Chapter2--2.1 Oracle Architecture Basics -
Branding：
谢谢，获益匪浅
《Pro Oracle SQL》--chapter 5--5.6 Building Logical Expressions -
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《Pro Oracle SQL》--Chapter 5--5.4 Questions about the Question -
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谢谢
《Pro Oracle SQL》 翻译序 -- 读书心得 -
jiaoshiguoke：
继续 加油
《Pro Oracle SQL》--Chapter 6--6.1 Explain Plans--之三
文章列表
Lead and Lag
(page 249)
Lag and lead functions provide inter-row referencing ability. Lag provides the ability to access prior row in the result set. The lead function allows access to later row in the result set.
Lag和lead 函数提供了行间引用的能力。Lag提供访问结果集中(当前行)之前行的能力。lead函数则允许访问结果集中 ...
Aggregation Functions 聚合函数 (page 246)
Aggregation functions can operate in analytic mode or conventional non-analytic mode. Aggregation
functions in non-analytic mode reduce the result set to fewer rows. However, in analytic mode,
aggregation functions do not ...
《Pro Oracle SQL》Chapter 8 -- 8.1-8.2 Anatomy of Analytic Functions -8.3
- 博客分类：
- Pro Oracle SQL Chapter 8
Riyaj Shamsudeen (page 243)
Online Analytic Processing (OLAP)
queries perform multi-dimensional aggregation and are useful in
business decision-making processes in areas such as sales, marketing, and business intelligence. Fast
execution is important for OLAP queries as key decisions hing ...
SQL Execution – Putting It All Together SQL执行--把所有放在一起
(page 81)
Now that I’ve covered the details, I’m ready to put the whole picture
of how a SQL statement executes together. Figure 2-4 shows the steps
that are involved when a SQL statement executes.
既然我已经详述过了，我准备把SQL ...
Executing the Plan and Fetching Rows 执行计划和取出行
(page 78)
After the optimizer determines the plan and stores it in the library cache for later reuse, the next step is to actually execute the plan and fetch the rows of data that satisfy your query. I’m going to ...
Determining the Execution Plan 确定执行计划 (page 74)
When a hard parse occurs, Oracle will determine which execution plan is best for the query. An
execution plan is simply the set of steps that Oracle will take to access the objects used by your query
and return the data that satisfies ...
Query Rewrite with Materialized Views 用物化视图重写查询
(page 72)
Query rewrite is a transformation that occurs when a query, or a portion
of a query , has been saved as a materialized view and the transformer
can rewrite the query to use the precomputed materialized view data
inste ...
Predicate Pushing 谓词推进
(page 69)
Predicate pushing is used to apply the predicates from a containing query block into a non-mergeable
query block.
The goal is to allow an index to be used or allow for other filtering of the data set earlier in
the query plan rather th ...
Subquery Unnesting 子查询反嵌套
(page 66)
Subquery unnesting is similar to view merging in that just like a view a subquery is represented by a
separate query block. The main difference between mergeable views and subqueries that can be
unnested is loc ...
View Merging 视图合并
(Page 62)
As the name implies, view merging is a transformation that expands views, either in-line views or stored views, into separate query blocks that can either be analyzed separately or that can be merged with the rest of the query to form a single overall ex ...
Query Transformation 查询变换 (Page 61)
Prior to the development of the execution plan, a step called query transformation occurs.
This step
happens just after a query is checked for syntax and permissions and just before the optimizer computes
cost estimates for the various plan oper ...
SGA – The Buffer Cache SGA-缓冲区缓存
(page59)
The buffer cache is one of the largest components of the SGA.
It stores database blocks after they have been read from disk or before they are written to disk. A block is the smallest unit that Oracle will work with.
Blocks contain ...
2.4 Identical Statements 同样的语句
(page56)
In order for Oracle to determine if a statement has been previously executed, it will check the library
cache for the identical statement. You can see what statements are currently stored in the library cache
by queryin ...
The Library Cache 库缓存
(page 54)
The first thing that must happen to every SQL statement you execute is that it must be parsed and
loaded into the library cache.
The library cache, as mentioned earlier, is the area within the shared pool
that holds previously pa ...
2.2 SGA – The Shared Pool 共享池 (page 53)
The shared pool is one of the most critical memory components particularly when it comes to how SQL executes. The way you write SQL doesn’t just effect the individual SQL statement itself. The combination of all SQL that executes agai ...