virtualbox pros and cons

Solution Solutions Advantages Disadvantages Jacob Powerful features Direct call to the VBA interface, the program is very complex, the server must be: Windows System + Office installation, server-side Automation COM interface prone to death process caused by server downtime Apache POI Powerful operation on Excel; cross-platform The ability to manipulate word is weak; You must write different code for DOC and docx two document formats; p

varReg =NewRegExp ("(^|)" + name + "= ([^]*) (|$)", "I"); Console.log ("location.search===" +Location.search); //substr (1): Extracts some characters from the first position of a stringConsole.log ("location.search.substr (1) = = =" +location.search.substr (1)); //match (): Retrieves the specified value that matches the regular expression within the string, returning an array to rConsole.log ("Window.location.search.substr (1). Match (reg) = = =" +window.location.search.substr (1). Match

interface, using the thread class's CurrentThread () to get the current thread object Try{Thread.CurrentThread (). Sleep (100); } Catch(interruptedexception e) {e.printstacktrace (); } System.out.println (Name+ ": " +i); } } } StaticFuturetaskNewFuturetaskNewCallable() {@Override PublicString Call ()throwsinterruptedexception {String name= ""; inti = 0; for(; i ) {Name=Thread.CurrentThread (). GetName (); Thread.CurrentThread (). Sleep (100); SYSTEM.OUT.PRINTLN (Nam

This article mainly introduces JavaScript to create a closure of the two ways of the pros and cons of the analysis of the relevant data, the need for friends can refer to the Usually javascript creates closures in two different ways. Constructor method: ? 1 2 3 New function () {var variable ...} Inline execution Mode: ? 1 2 3 (function () {var variable ...}) (

, and so on exactly what, you should use MySQL. 3, if your application to the integrity and seriousness of the data requirements is not high, but the pursuit of high speed processing. For example, it is a forum and community where you should use MySQL. 4, your application is a serious business application, the data integrity requirements are high. And you want to have a good encapsulation of some business data logic, such as an online bank, you should use PostgreSQL. 5, your application is deali

distribution that's right for your desktop, and if you don't want to customize anything yourself, and you don't want to waste too much time on your system, it's easy, You choose according to your hobby in Ubuntu, Kubuntu and Xubuntu, the difference of the three is only the desktop program is different.If you need a server system, and you are very tired of the various Linux configuration, just want a more stable server system, then your best choice is CentOS, after the installation, after a simp

the MFC SDK for free.QT is free to get its GPL-compliant version on UNIX (note: The GPL version is now available for free on Windows). If you want to develop software that is unfair to open source code, you must purchase QT authorization. Under specific platforms, each developer buys a permanent license and receives one year of technical support. (Translator Note: After the purchase price and other issues to be deleted, because the price is not fixed, if in doubt, please go to the official webs

pointed to the object that created the current instance. Console.log (P5 instanceof Child4, p5 instanceof parent4); The result is the same, and P5.constructor is not child4 but parent4.5. Combinatorial inheritance optimization 2--parasitic combined inheritance functionparent5 () { This. Name = ' PARENT5 '; This. play = [1, 2, 3]; } functionchild5 () {Parent5.call ( This); This. Type = ' Child5 '; } Child5.prototype=object.create (Parent5.prototype); Child5.prototype.constructor=Child5

Due to not how to contact Oracle so did not answer this question, now after the data summarized below. Later have the opportunity to learn to learn Oracle, do not know how the written test, I hope God did not go to the WC. Pros and cons of hot and cold backupsThe advantages of hot backup are:1. Can be backed up at the table space or data file level for short backup time.2. The database is still available f

include| Safety | Safety |include| Safety | What are the pros and cons of security include? Do you know that include can contain the file itself? Yes. You can even include several times. The only limit is: You can't let a contain B, and B contains a. Such a loop inclusion is not allowed. Another question is, can those files contain other files? In fact, by setting up IIS, you can allow any file type to use

, he may become a car industry experts. But in fact this is rare, and many architects may face another new project, such as you used to make a car, and now you do finance, what do you do. So our general practice is that if a large company, a large team, we will have specialized field experts, by the domain experts to take charge of the business this piece, or by the customer to take charge of the business this piece. But our architects also have to have a certain understanding of the business, a

aborts, the cluster returns a deadlock error code (error:1213 sqlstate:40001 (Er_lock_deadlock)).(7). XA transactions are not supported due to possible rollback on commit.(8). The write throughput of the entire cluster is limited by the weakest node, and if one node becomes slow, the entire cluster will be slow. For stable high-performance requirements, all nodes should use unified hardware.(9). Cluster nodes suggest a minimum of 3.(10). If there is a problem with the DDL statement, the cluster

Now say the common editor, and we compare the differences between the editor and the pros and cons, I usually use the editor is vim, of course, there are many editors. On this blue planet, there are legends of two great artifacts: Emacs is said to be the editor of God, and Vim is the god of the editor. Emacs is an operating system disguised as an editor There is an exaggerated saying: Emacs is an operating

performance is also controllable (100 SQL statements interact once, even if the delay is increased from the same city 1ms to an offsite 50ms, also just increase 49ms, if the interaction 100 times, then increase 4900ms). In the Internet industry, where stored procedures are rarely used, one important reason is the widespread use of MySQL, while the MySQL stored procedure is weak (compared to a commercial database) and has a certain relationship with the changes in the Internet industry. Ci

the Key_len data column for the length of the byte count. For example, for an index of an integer data column, the byte length would be 4. If a composite index is used, the Key_len data joins can also see which parts of MySQL it uses. As a general rule, the smaller the value in the Key_len data column, the better (meaning faster).The Ref data column gives the name of the data column in the other data table in the association relationship. The row data column is the number of data rows that MySQ

change the value of the other fields in the record, the value of the DateTime field does not change unless you manually change it. Timestamp1. Take up 4 bytes of 2. Null values are allowed, but values cannot be customized, so null values are meaningless.3. The timestamp value cannot be earlier than 1970 or later than 2037. This indicates that a date, such as ' 1968-01-01 ', is valid for a datetime or date value but is not valid for the timestamp value, and is converted to 0 if assigned to such

data column gives the name of the data column in the other data table in the association relationship. The row data column is the number of data rows that MySQL expects to read from this data table when it executes this query. The product of all the numbers in the row data column gives us a rough idea of how many combinations this query needs to handle.Finally, the extra data column provides more information about the join operation, for example, if MySQL had to create a temporary data table wh

most widely used are Sybase 10 and syabse for SCO Unix.Features of the Sybase database:(1) It is a database based on the client/server architecture.(2) It is a truly open database.(3) It is a high-performance database.5.db2DB2 is a database management system embedded in IBM's AS/400 system, supported directly by the hardware. It supports the standard SQL language and has a gateway connected to heterogeneous databases. Therefore, it has the advantages of fast speed and good reliability. However,

processing, then using MyISAM is the best choice for performance. (3) The size of the InnoDB table is more large, with MyISAM can save a lot of hard disk space. In this 38w table we tested, the table takes up space as follows:Engine Type MyISAM InnoDBData 53,924 KB 58,976 KBIndex 13,640 KB 21,072 KBTotal space occupied 67,564 KB 80,048 KBAnother 176W record table, where the table occupies space, is as follows: Engine Type MyIsam InnordbData 56,166 KB 90,736 KBIndex 67,103 KB 88,848 KBTotal spac

:"Datasource=aron1;initial catalog=pubs;integrated Security=sspi;"-OR-"Server=aron1;database=pubs; Trusted_connection=true; "(Bothconnection strings produces the same result)(Useservername\instancename as Data Source to use an Specifik SQL Server instance,only SQLServer2000)3. Connect via an IP address:"DATASOURCE=190.190.200.100,1433; Network library=dbmssocn;initial catalog=pubs; Userid=sa; PASSWORD=ASDASD; "(Dbmssocn=tcp/ipinstead of Named Pipes, at the end of the that the Data Source is the