ibb talk

operation takes the current version number of the data that needs to be locked, and then actually updates the data again, the version number confirms the same as the previous fetch, and the version number is updated to confirm that no concurrent modifications have occurred. If the update fails to assume that the old version of the data has been modified in parallel and does not exist, it is assumed that the acquisition of the lock failed, you need to roll back the entire business operation and

only one row of data, but in the case of a range query, the performance increase will grow with the number of result sets.For such scans, the index must contain all the fields involved in the query, as well as the leading column in the WHERE clause that contains the index, such as a composite index that contains a,b,c,d four columns, and A is the boot column. If the included column in the WHERE clause is a BCD or BD, you can only use a non-matching index scan.2) non-configured index scanAs ment

: ValidationEmpty the Linux environment, reload MySQL, import without the-R parameter without the backup file that created the stored procedure SQL[[Emailprotected]~]#mysql-uroot-pIt is found that stored procedures created earlier can still be called even if the-R parameter is not added.-- summary --The stored procedure is stored in the Mysql.proc table, and the stored procedure is backed up by the use of a full-library backup strategy that includes the MySQL library. The-r parameter is typica

in the water stains, oil, smoke in the harsh environment, the whole image of the temperament Berthelot off a clay turtle, the two is that this is not the work of the landlord want, Sometimes see our department and add some new 66-year-old younger brother I feel sorry for them, so in quit before the landlord has been on the internet to find a variety of career change work, at the beginning of the beginning, I also met a lot of career change people encountered problems: that is, what to do? In ad

sort (default), and Desc is sorted by a large variable--in reverse order.The fields in the GROUP By Field List Field list must appear in the field list of the SelectHaving query conditions He is a query condition used with GROUP by6. Query condition RelationshipLike fuzzy queryIn contains query=/>/7. Functions that can be used in the field listCOUNT (*) Record CountSUN (field name) gets the total of the specified field, and of course the specified field must be numeric before it can be summed.M

, to do a certain IP access frequency limit, to avoid being reasonable use of attacks.Third, appendixRecommend a website: zooomeye, Zhong Eye, is a search engine for cyberspace. His crawler is dedicated to scanning the server on the network, for example, he got an IP, began to detect which ports on the IP open, using some methods to obtain important open services information.With him, you can make a simple vulnerability scan of your own server (provided that he has updated your server's informat

possibilitiesSince the start of the deployment with the pagoda Linux, so to download the official website toolshttps://www.bt.cn/Installing CentOS:Yum Install wget wget install. sh http:///download.bt.cn/install/install.sh sh install.shAfter the successful landing, after the installation interface, it pops up the login background information (an address and background login password and account)Finally, through the graphical interface to solve the view hard disk found full, and finally remove

1. Add a piece of data to the database: Alter //Added a field to the table INSERT into table name values (' Bill ', ' Male ')//Add data to the Dspcode,dspsex field added to the table2. Database deletion:-- Deleting a database drop databases name--Delete table, delete foreign key table first, delete primary key table drop table name-- Remove Delete unconditionally fromTable name-- Conditional Delete--Delete from table fromTable namewhereSName like'Xiang _'Delete fromTable namewhereSName ='Che

On the audio voice changer algorithm, this is a topic that many people are particularly interested in. Of course, there are many open-source algorithms to learn, there are time-domain-based, but also based on the frequency-domain algorithm. The final algorithm wants to achieve the same purpose. Recently there are many netizens asked about the voice changer algorithm some of the details of the problem, e-mail asked me. To give a more reasonable or easy-to-understand explanation, seemingly sim

3.3.3virtualmetadata13.3.4diskrecovery13.4 Stripe (asmstriping) 13.4.1ASM file Template (asmfiletemplate) 13.4.2ASM alias ( Asmfilealias) Interaction between 13.5RDBMS and ASM 13.6ASM Instance restores the interaction between 13.7ASM and Osfilesystem 13.7.1dbms_file_ Transfer package 13.7.2RMAN The Convert method 13.7.3ASM and Tts13.8asm Limitations 13.9 Summary 14th Chapter performance and RAC14.1RSeveral features of AC 14.2awr14.2.1 enable AWR14.2.2 modify AWR configuration 14.2.3 generate AW

prevent these vulnerabilities. Of course, the vulnerability is also changing, on the line after the deployment of a trend of the antivirus wall more insurance. = = As a rails developer, talk about the top ten web security vulnerabilities and how to guard against these vulnerabilities in rails development. A1-cross Site scripting (XSS) This is the cookie information that an attacker uses to embed JavaScript in a Web site to get a victim. Rails2.0

statements and run to produce results2 Dclgen automatic generation of table structures and host language definitions in different languages3 program Preparati the various parameters needed to prepare the application via multi-layer screen to complete the processPre-compile, compile, pre-connect, connect, and execute each step of the sequence4 Precompi LE Pre-compiles the source program by entering the necessary parameters in the screen5 BI Nd/rebi Nd/free bind, rebind, or release a schedule or

what engine the table uses (in the result of the parameter engine is the storage engine that the table is currently using): Mysql> Show create table table name;All performance tests are tested on computers with: Micrisoft window XP SP2, Intel (r) pentinum (r) M processor 1.6oGHz 1G memory.Test method: Submit 10 consecutive query, table records total: 380,000, time unit sEngine Type MyISAM InnoDB performance differenceCount 0.0008357 3.0163 3609Query primary key 0.005708 0.1574 27.57Querying for

This chapter talk about the modern front-end framework of the cognition, there is a certain reference value, the need for friends can refer to, I hope to help you. So why do people need to choose various frameworks now? In fact, we need to choose a framework now, essentially because the demands we face are changing. We all know that if we only write a page that displays information purely, there is no interactive function of the page, in fact, even n

\git_teacher\08> git Add. E:\teacher\git_teacher\08>git commit-m "update bug in 0.0.1" #完成一次修复并且提交 [hotfix-0.0.2 9d2d416] update bug in 0.0. 1 1 file changed, 1 insertion (+) e:\teacher\git_teacher\08>git checkout master #切换到master分支 switched to Branch ' master ' e:\teacher\git_teacher\08>git merge--no-ff hotfix-0.0.2 #合并hotfix分支 Merge made by the ' Recursive ' strategy. Base.txt | 1 + 1 file changed, 1 insertion (+) e:\teacher\git_teacher\08>git tag-a 0.0.2 #打一个标签0.0.2 The above operation

the database based on the log, returning the database to the initial state before the transaction was executed. The database management system adopts the lock mechanism to realize the isolation of the transaction. When multiple transactions update the same data in the database at the same time, only transactions that hold the lock are allowed to update the data, and other transactions must wait until the previous transaction releases the lock, and other transactions have the opportunity to upda

specifically written the Redis instructions. Ultimately, this service has only one Lua script, in fact it consists of three Skynet services, one listening to the external port, one processing the Redis synchronization instructions on the connection, a single point writing data to Unqlite. In order to make the data recovery efficient, I specifically saved the player data, the recovery of Redis instructions to spell. So once the recovery is needed, just read the player data from the Unqlite and s

, ' yyyy-mm ') = ' 2016-10 ' and substr (T2.DZYF, 0, 4) | | ' -' | | SUBSTR (T2.DZYF, 5, 2) = ' 2016-10 ';--4.full Join--4.1 all result set 106Select T1.fpdm,t1.fphm, T1.ZJR,T1.ZJSJ,T1.ZJJX,T1.ZJJE,T1.ZFLX,T1.ZFID,T2.FPDM,T2.FPHM,T2.ZFLX from YW_ZJFPJL t1Full join XXDZMX T2 on T2.FPDM=T1.FPDM and T2.FPHM=T1.FPHM--4.2 right, there's no 10-1=9 on the left.Select T1.fpdm,t1.fphm, t1.zjr,t1.zjsj,t1.zjjx,t1.zjje,t1.zflx,t1.zfid,t2.fphm,t2.fpdm,t2.zflx,t2.dzyf from Yw_ ZJFPJL T1Full join XXDZMX T2 on

other monitoring systems, now used more is Zabbix)5, operation and maintenance automation learning (need to learn some of the use of open-source operations automation tools such as Ansible, Puppet, cobbler and other operational automation tools)Can master here, basically can deal with a lot of work, can go to interview senior OPS engineer, almost pay can reach 12-18k around? Stage four: Senior Direction advanced1. Big Data direction (need to know more about common open source big Data systems s

Original address: http://www.cnblogs.com/jfzhu/p/4298427.htmlReprint please indicate the source"Home", "dumb", "difficult to communicate" is often the label that people put on the programmer, then this article will talk to programmers about how to better talk to strangers.(i) Body movementsStudies have shown that body language plays an important role in people's conversation when it comes to narrowing their