xiechangming
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ldd600：
写的不错，可以适当的展开一些，比如企业架构中常用的分层模式，以 ...
设计分层架构的步骤(一) -
liberD：
这也正是我需要考虑的，希望楼主继续加油！期待楼主针对这个问题展 ...
设计分层架构的步骤(一)
文章列表
Declareing a type as sealed prohibits the use of the types as base type. Declaring a type as abstract, on the other hand, disallow direct instantiation of the type and make it useful only as a base type.
The policy for dealing with collisions when method names or member names are reused is somewhat ...
Interface is just another type of the CLR. Interfaces can have members, with the restriction that an interface cannot have instance fields nor instance methods with implementation.
One can view interfaces as partitioning the set of all possible objects into subsets. Which subsets an object belongs ...
Types are allowed to provided a distinguished method that is called when the type is first initialized. This type initializer is simply a static method with a well-known name(.cctor). A type can have at most one type initializer, and it must take no parameters and return no value. It is called automa ...
Outlining the Development Process
First requirement analysis, overall user case
Overall Shell-design
Shell implementation and tests
Infrastructure services implementation and tests
Use Case Analysis
Overall WorkItem design
Use Case refinement
Final WorkItems des ...
一．选择你的分层策略(未完)
分层就是将应用系统的每个组件逻辑地划分为一个个有着特定角色和特定功能的组。使用分层的形式能够增加你应用系统的可维护性，并且在需要性能调优时能更方便地扩展。有很多种不同的方式将相关的功能划分到层里。然而，划分的层数太多或太少会增加不必要的复杂性。决定适合你应用系统的分层粒度是选择分层策略中的关键的第一步。
你必须同时也考虑到你分层的目的是仅仅为了将功能进行逻辑拆分，还是也为了可能的物理分级。层间边界交互会增加本地性能开销，特别是组件间的边界交互是物理远程交互。然而，你应用系统在可扩展性和可适应性方面的增加带来的好处会足以超过这些性能开销。另外，分层可以使得对某一层 ...
Once I encounter a problem that the used space of temporary tablespace always increases till out of space on production environment, an “ORA-1652: unable to extend temp segment” error rises at last which causes the application crashed. Later restart application server, the used space releases i ...
开始设计应用系统时，你的第一个任务就是处于最抽象级别之上将功能划分到各层里。接下来，你必须依据你设计的应用系统的类型为每一层定义公共接口。一旦你定义好了分层和接口，你必须决定应用系统将如何部署。最后，你需要选择应用系统的各逻辑层间、物理级间的交互所使用的通信机制。尽管你设计的分层结构和接口可能会随着时间不断变化，特别是你使用敏捷开发时尤其如此，但这些步骤会确保你在开发过程的早期就在某些重要的方面有所考虑。典型的设计步骤如下：
1． 选择你的分层策略
2． 决定你需要的层次有哪些
3． 确定将如何分布层次和组件
4． 决定你是否需要合并某些层次
5． 确定层间交互的规则
6． 识别出横跨层间的通用 ...
不论你设计的应用系统是何类型的，是否有用户界面或是只是一个提供服务的服务程序(请不要将此服务与应用系统的服务层混淆)，你都可以将应用系统设计成为基于软件组件来分组的逻辑组集。这些逻辑组就叫做层。分层有助于区分不同的由这些软件组件提供的功能的类型，从而使得做出一个能够具有高可复用这些软件组件的设计变得更为简单。每一个逻辑层可包含多个不同的组件类型，且具有相同类型的组件可再被划分为一个个子层，每个子层都展现着特定功能的类型。
通过标识出存在于大多数系统中的通用组件的类型，你可以构造出应用程序或服务的分层映射，然后使用此映射来作为你设计的蓝图。将应用系统分成具有特定角色和功能的层有助于最大化地增加代码 ...
On occasion giving a date time with a time zone, we want to get the date time under another time zone, how to do it? Here gives a solution:
FUNCTION fun_exchange_timestamp_tz(pv_timestamp TIMESTAMP,
pv_from_tz VARCHAR2,
pv_ ...
On occasion we need split and treat a single comma-delimited value as if it were a column in a table. There are two methods to achieve this.
1.TABLE SQL function
We can take advantage of the TABLE SQL function and PL/SQL function to do this.
Example:
CREATE OR REPLACE TYPE GTYP_STR_TABL ...
In some cases, it is necessary to aggregate data from number of rows into a single row, giving a list of data associated with a specific value. There are some methods to achieve this.
LISTAGG Analystic Function in 11g Release 2
The LISTAGG analytic function was introduced in Oracle 11g Release 2, ...
If you want to migrate the source db data to a target db while you don’t have privileges of Read/Write Directory on the source db, then how to export the source db data and migrate them to the target db?
Here we can use network_link feature of expdp/impdp. There are two ways to implement the migrati ...
In general, the extents of a segment do not return to the tablespace until you drop the schema object whose data is stored in the segment (using a DROP TABLE or DROP CLUSTER statement).
A database administrator (DBA) can deallocate unused extents using the following SQL syntax:
ALTER TABLE table_na ...
The PCTFREE Parameter
The PCTFREE parameter sets the minimum percentage of a data block to be reserved
as free space for possible updates to rows that already exist in that block.
The PCTUSED Parameter
The PCTUSED parameter sets the minimum percentage of a block that can be used for
row ...
If you drop a table or delete data mistakenly, then want rollback them, you can take the following methods:
1. Query the data before delete:
Select * from table_name as of timestamp date_before_delete.
Once you get the data before delete operation, how to recovery the data is needless to exp ...