what is fact and dimension in data warehousing

In a php file, I define two forms. when the first form is submitted, the second form is generated. after the second form is submitted, the data of the first form cannot be obtained, what should I do? Form php submit transfer data

QQ is added, and the submitted data is not stored. what's the problem? in the recommended registration file, only the user name and password can be entered. I want to add a QQ user, however, QQ is not stored in the table. what is

time? 3: What if one read and one write at the same time? Transactions are not considered. To answer:1: There are no locks for different select statements in innodb, and Myisam will automatically add table share read locks; 2: innodb has no locks, so there is no problem. Myisam is a table shared read lock. The shared read locks do not conflict with each other

large amount of data (although many people have the big data defined above the T level, in fact, I think this is problematic, big data in fact should be a relative concept, is relative

characterized by a large amount of data (although many people have the big data defined above the T level, in fact, I think this is problematic, big data in fact should be a relative concept,

There are 8 basic types of data in Java:Integer type: Byte (8), short (16), int (32), Long (64)Float type: float (32), double (64)Character type: char (16-bit Unicode character)Boolean type: BooleanAuto-unboxing is supported after jdk1.5Auto-Boxing is a conversion of the Java compiler between the base data type and the

What is the data structure ?, Data structure? What is the data structure? A Data Structure is a

within the range of the variable's expression, such as an out-of-scope program that compiles an error.2) Char type (character type)one character (char) in Java represents an element in the Unicode character set.Unicode characters are made up of 16 bits, so there are (65535) different characters available,The Unicode character set contains all the characters in different languages, as well as the usual symbols in math, science, and text, so it gives us a lot of flexibility.A single character exp

experience. So from the mastery of the skills, the two are very different, the data Modeler in fact rarely mentions the word algorithm, more say what model to use, have feelings? However, from the practical perspective, these two models more and more do not have a clear division of labor, in general, will be two positions of people will learn each other's knowle

information in the data warehouse is consistent global information about the entire enterprise. The so-called time-based changes indicate that the information in the Data Warehouse does not only reflect the current state of the enterprise, but records information from a certain time point in the past to the current phase. With this information, you can make a qu

Ex.change (ex.str,ex.ch);7System.out.print (ex.str+ "and");8 System.out.print (ex.ch);9 }Ten Public voidChange (String str,Charch[]) { Onestr= "Test OK"; ACh[0]= ' C '; - } -}The answer to the output is:? Hello and CB;It is explained that the string class is of the final type and cannot inherit and modify the class. str= "Tesk OK", in

Share with you what spark is? How to analyze data with spark, and small partners who are interested in big data to learn about it.Big Data Online LearningWhat is Apache Spark?Apache Spark is