concept pm3

, the permission setting mode changes, 12 uses the role to connect the OU, the user assigns the role the way, the processing multi-ous business does not need to switch frequently.4, ledger the definition of the elements of 4C, respectively, the original 3c+accounting Convention (accounting method).5, the new introduction of the concept of ledger set, when the COA and calendar consistent time can be defined as a number of ledger as a ledger SET, the ro

Tags: Intent permissions CTO blog Linux tor file name src logThe Inode concept in LinuxInode in LinuxTo understand the inode, begin with the file storage. The file is stored on the hard disk, then the smallest storage unit in the hard disk is called "Sector", here simply jump out, and tell you a simple explanation of what is called sector, such as:The following is a single hard disk disc, a hard disk is a number of the same platters (specific details

Basic concepts of relational databasesDatabase :An efficient solution for managing large amounts of information.A library that organizes, stores, and manages data in accordance with its data structure .Database Systems (dbs,database system):Database (db,database) + Database management systems (Dbms,database MANAGEMENT System)relational databaseA database system built on a relational model.Relational Model:How the entity structure should be handled when the attributes of the entity (student) and

Recently just learned multi-process, for the concept of multi-process I myself summed upEach program is started and a process is generated in the system to process the program.However, a process running speed is limited, there are some more time-consuming procedures in the program can only be stuck in the state, in order to solve this problem, there are many processes. Let the time-consuming work create a child process that lets the child process go t

as follows:+-------------------+| Add_tax (100) |+-------------------+| 110 |+-------------------+After you have defined stored procedures and stored functions, you can view the code that defines these procedures and functions by using statements such as the following:Show create procedure total_orders; or show create function add_tax;You can also use the following statements to delete them:drop procedure total_orders; or drop function add_tax;Stored procedures provide the ability to use contro

Definition Concept definition: Uses refined statements to display the connotation of a concept, that is, to reveal the special or essential attributes of the object reflected by the concept. Definitions can be divided into substantive definitions and word definitions. Substantive definitions reveal the inherent or essential attributes of objects. The basic method

In the previous article, we discussed what a schema is. In fact, these basic concepts are very important for architecture, and most people think they are aware of the concepts they are accustomed to every day, but in fact they are subconscious and not active. For example, "What is a table?" "When I do training, I often take this example to ask you, answer all sorts of strange things." This actually led to the structure of the time, the different roles of communication will be a lot of problems,

avoids unnecessary inter-cache replication as much as possible, and only performs operations in the correct location. For example, when dealing with routes, URL decoding is done before routing matches.=large Open Source Contributors, I need your help.I have been continuously developing japronto for more than three months, not only on every business day, but also on weekends. In addition to my daily work, I devote all my time and energy to this project.I think it's time to share the fruits of my

: D stack top elements: C stack elements: C Stacks top elements: B-Stack elements: B Stacks top elements: A stack element: a stacks no elements in the empty stackSummarizeReal life in the use of mobile phones, screen pages of the jump using the stack structure (jump page, the previous page will be stored in the stack, the fallback operation will go back to the previous page, which is the effect of the stack page out). In addition to seeking n! , it can be implemented by the recursive return of t

True and False Very similar to C and C + +, but unlike Java, JS is considered a wide range of true or false. All objects (except for empty strings) and non-0 numbers are treated as true. An empty string, 0, NULL, and undefined are treated as false.Undefined is a special value. All variables that are not assigned any value are undefined. Clear? :) again, all functions that do not return a value actually return undefined. In fact, it is a key word. Therefore, the following code is valid:var a =

version1. Linux boot up2. linux File Management3. Architecture of Linux4. Linux command line and command5. linux file Management related commands6. Linux text stream7. Linux Process Basics8. Linux Signal Basics9. Linux Process RelationshipsTen. Linux UsersLinux from program to processLinux multi-Threading and synchronizationInter-process communication between LinuxImplementation of Linux file system===============================================Add:Linux Common commandsIf you are interested in

Axz|grep passwd user_u:user_r:passwd_t 4299 pts/1 s+ 0:00 passwd at this point we see that the domain of the passwd process is passwd_t. ③ Policy Analysis tool Apol This is a very useful tool for checking policy content, developed by Tresys Technology, and released with the SELinux Toolkit as a setools. The Setools package is included in most SELinux release packages and runs the Apol command to determine if the tool is installed on the system, and if no Apol

segment, but the actual network cannot transmit such large data, and the MTU, when the message length exceeds the MTU, is divided into several packet lengths of the MTU (the last segment may be small), and then the transmission is carried out separately.IP segmentation is usually reorganized on the destination host (intermediate devices need to be reorganized if the entire IP packet needs to be viewed).Fragmentation and reassembly work consumes CPU and memory, and may consume excess network ban

organization, and he wants us to open up a memory space, C, and put A+b in.Cpu:a+b, I've already worked it out. I just applied for a memory address, and the Memory brothers put A+b in the memory address.Memory: OKSummary: The memory bar is specifically responsible for the storage and reading of the data CPU to the address to be read to the memory Bar memory bar to find this memory to take the value inside out to the CPUThe display card display card also has a storage data place called the memor

. (Note that the assignment cannot exceed the allowed range of this bit field) the 12th line of the program outputs the contents of three fields in an integer format. The 13th line sends the address of bit field variable bit to pointer variable pbit. The 14th row assigns a value to bit field A as a pointer to 0. Line 15th uses the compound bitwise operator "=", which is equivalent to: pbit->b=pbit->b3 bit field B has a value of 7, and 3 for bitwise AND operation results of 3 (111011=011, decimal

, if the resource-hogging thread has been reluctant to release resources, all other threads that are blocking the critical section will not work.Non-blocking allows multiple threads to enter the critical section at the same time.2.5 deadlock, hunger and live lockDeadlock,starvation,livelockDeadlock: preemption of resources without releaseStarvation is the inability of one or more threads to get the resources they need for a variety of reasons, causing them to fail to execute. For example, a thre

LINUX Signal Concept DetailedWe run the following command to see a list of supported signals from Linux:# kill-l1) SIGHUP 2) SIGINT 3) Sigquit 4) SIGILL5) SIGTRAP 6) SIGABRT 7) Sigbus 8) SIGFPE9) SIGKILL (SIGUSR1) SIGSEGV) SIGUSR213) sigpipe) sigalrm) SIGTERM) SIGCHLD18 (SIGSTOP) SIGTSTP) SIGTTIN22) (Sigttou) Sigurg) sigxcpu) SIGXFSZ26 27) SIGPROF) (sigwinch) SIGIO30) SIGPWR Sigsys) sigrtmin) sigrtmin+136) SIG rtmin+3) (sigrtmin+4) sigrtmin+54

implementation details or method bodies for any abstract method; Note: It is said that in these cases a class will become an abstract class, without saying that abstract classes are bound to have these conditions. A typical error: An abstract class must contain an abstract method. But conversely, the "class containing abstract methods must be abstract" is correct. In fact, an abstract class can be a completely normal implementation of a class Series Articles:Ja

ImportCopy a= [1, 2, 3, 4, ['a','b']]#Original Objectb= A#assignment, a reference to a passing objectc = Copy.copy (a)#object Copy, shallow copyD = Copy.deepcopy (a)#object Copy, deep copyA.append (5)#Modify Object AA[4].append ('C')#Modify the [' A ', ' B '] Array object in Object a Print 'A =', aPrint 'B =', bPrint 'C =', CPrint 'd ='DThe output is:A = [1, 2, 3, 4, [' A ', ' B ', ' C '], 5]b = [1, 2, 3, 4, [' A ', ' B ', ' C '], 5]c = [1, 2, 3, 4, [' A ', ' B ', ' C ']]D = [1, 2, 3, 4, [' A

is random, and it can be arbitrary. Therefore, the pointer variable should be initialized at the same time it is created, either by setting the pointer to null or by pointing it to legitimate memory. Second, after the pointer p is free or delete, it is not set to NULL, which makes the person mistakenly think P is a valid pointer. Although the names of free and delete are ferocious (especially delete), they simply release the memory that the pointer refers to, but do not kill the pointer itself.