paradigm paralysis

The advantages of normalization: Normalization of update operations is usually faster than inverse normalization. When the data is well normalized, there is little or no duplication, so you only need to modify less data. A normalized table is usually smaller and better placed in memory, so it is faster to perform the operation. There is little extra data that means fewer distinct or group by statements are needed to retrieve list data. Disadvantages of Normalization:

Label:2, the second paradigm 2NF Definition: A non-critical field in a database table does not have a partial function dependency on any of the candidate key fields, which conforms to the second paradigm. Simply put, no field redundancy. Note: What is function dependence, see Baidu Encyclopedia (http://baike.baidu.com/view/40008.htm). If the value of a field a in a table is determined by the value of anot

Our paradigm theory is a step-by-step process. If a data table already meets the first paradigm, and the values of any non-primary key field in the data table depend on the primary key field of the data table, the data table meets the 2nf paradigm; We still look at the figure, because the figure best illustrates the problem. We can see that figure 1 shows that t

Tags: HTTPS PAC cin cannot be stored directly padding collectionDatabase design generally satisfies the third paradigm. The first paradigm (no duplicate columns) is defined: Each column of a database table is an indivisible atomic data item, not a collection, an array, a record, and other non-atomic data items. If an attribute in an entity has multiple values, it must be split into different properties popu

This time the teacher assigned the following machine work, not limited to language. After thinking, asked a few big gods, said a bunch of not know what Ghost algorithm name ....After some Baidu, found that Java can contain libraries and then use some JavaScript functions, where the eval () function can calculate a string, and execute the JavaScript code in it. Http://www.w3school.com.cn/jsref/jsref_eval.asp thought of the following solution:1 ImportJavax.script.ScriptEngine;2 ImportJavax.script.

Database design paradigm and its significance and deficiencies The database design paradigm is the norm which the database design needs to meet, the normalization of the database is the way to optimize the table structure and to organize the data into the table, so that the data is clearer and simpler. In practice, a database is usually divided into two or more tables and the relationships between tables ar

Special methods and multi-paradigm for Python deep learning, and python deep learning paradigm Python is an object. But at the same time, Python is also a multi-paradigm language. You can not only write programs in an object-oriented way, you can also use process-oriented methods to compile programs with the same functions (as well as functional and declarative p

[Original] Command Line Parameter Parsing and configuration programming process paradigm, command line parameter paradigm When studying the open source code of Bitshares 2.0, I was amazed at the excellent process of parsing the command line parameters in the main function of witness_node. Here we will post the code for appreciation: 1 namespace bpo = boost: program_options; 2 3 ............... 4 ...........

The first paradigm means that each column in a data table is an inseparable basic data item (that is, each column in the database must store some basic data). The same Column cannot contain multiple values, that is, an attribute in an object cannot have multiple values or duplicate attributes; The first paradigm includes the following guiding principles: Each attribute of an array can only contain one valu

Tags: single-table problems objective thinking map logical thinking ideas multi-table improved simplificationDatabase design, is a model, is in the actual production of the project, according to how the steps to do. Less redundancy, more than a pair of ah, and so on.So back to the question: is the database meant to be added or to be queried? This problem has some axes, in order to increase the deletion of the four laws, it is important.Then the database itself is used by people. So the streamlin

3. The third paradigm 3NF Definition: On the basis of the second paradigm, if there is no non-critical field in the data table, the transfer function dependency on either of the candidate key fields is 3NF compliant. Let's take a look at the optimized table in the example above 3-1 studentno cardno userid userlevel date time 0211

Linux Client/Server programming paradigm 2 -- Concurrent Server (process pool), linux paradigmIntroduction Let the server call fork to create a sub-process pool during the startup phase and process client requests through sub-processes. Use socketpair to communicate with the parent process (to facilitate the use of sendmsg and recvmsg, if the anonymous pipeline is used, the above two functions cannot be used ). The following is an analysis of TCP. Th

The database paradigm 1NF2NF3NFBCNF (Instance) design paradigm (paradigm, database design paradigm, database design paradigm) is a set of relational patterns at a certain level. Database construction must follow certain rules. In relational databases, this rule is a

The design paradigm (paradigm, database design paradigm, and database design paradigm) is a set of relational patterns at a certain level. Database construction must follow certain rules. In relational databases, this rule is a paradigm. The relationships in relational datab

(From: http://www.itisedu.com/phrase/200604241410105.html) Design paradigm (Paradigm, database design paradigm, and database design paradigm) is a set of relational patterns at a certain level. Database construction must follow certain rules. In relational databases, this rule is a