qc alm

Delphi7 vclfixpack 1.4 : Http://download.csdn.net/source/3125333 Fixed several bugs in Delphi7. Now Delphi7 is no longer officially maintained. This is the latest bug patch: ConstVclfixpackrevision = '1. 4 ';Vclfixpackdate = '2014/1/09'; // yyyy/DD/MM {Usage=====Add the unit to the. DPR file's uses-list.C ++ builder user can add the file to the project (menu Project/Add to project) Example========UsesFastmm4, // optional Memory ManagerVclfixpack,Forms,Unit1 in 'unit1. pa '; Fixes the following

Filter all comments Remove the space before the SQL text, tab, and so on. Note that the front and rear of the text. The middle will not be removed. In the following three SQL, because of the Select Case relationship, the last one and the other two are definitely different storage locations in the QC. And the first and second, the difference is that the latter have a comment, in different clients, there will be the same result. So, to be on the safe

Original article: http://dinglin.iteye.com/blog/1625195 Some people ask whether the locks of querycache (QC) in MySQL are "global locks" or "Table locks ". Here is a brief description. 1,Basic QC concepts This is a memory structure implemented in the MySQL layer (non-engine layer). The basic rule is to cache query results that meet certain conditions in the memory. If the same query is executed for the s

The query cache mechanism of Mysql is QueryCache, which is based on SQL statements. If an SQL query starts with select, the MySQL server will try to use QC for it. Each Cache is saved using SQL text as the key. Before QueryCache is applied, SQL text is not processed. That is to say, as long as the difference between the two SQL statements is one character (for example, case is different; there is one space), the two SQL statements use a different Quer

MySQL query caching mechanism principle Querycache,querycache is based on SQL statements to cache. If a SQL query starts with SELECT, the MySQL server tries to use QC for it. Each cache is saved as a key with SQL text. SQL text will not be processed until Querycache is applied. In other words, two SQL statements, as long as the difference is even one character (such as the case is not the same as a space, and so on), then the two SQL will use a differ

SPACEBAR to continue, pressing Q key to exit)", disable the ringing function-L ignores Ctrl+l (page break) characters-p to page a file by clearing the window instead of scrolling, similar to the-C option-S displays a contiguous number of empty rows as a row-U Remove the line from the contents of the file4. Common Operation Commands:Enter down n rows, which need to be defined. Default is 1 rowsCTRL+F Scroll down one screenSpace bar scroll down one screenCtrl+b Back to previous screen= Output the

MySQL query Cache When the query cache (QC) function is enabled for your database, the database puts the results in QC when executing the SELECT statement. When the same select request is processed, the database will obtain results from QC without querying the data table. In this era of "cache is King", we always cache our results in different ways to improve r

Background1. A mobile game v1.0 has been released to the App Store;2. this mobile game does not support multi-version client compatibility. That is to say, if the current server version is v2.0, you will be prompted to upgrade when you open the v1.0 client; otherwise, you will not be able to enter the game;3. the player's primary key in the database is determined by the Device ID and Game Center ID;4. There are two teams: one is the development team and the other is the operation team );5. QA in

following mainly analyzes the bfin_bmdma_setup and bfin_bmdma_start functions, namely the DMA Operation Process: (1) The software has prepared a PRD table in the memory, each 8 bytes, aligned to the 4-byte boundary. (2) The software sets the start address of the PRD table, and sets the data and transmission direction by setting the read/write control bit to clear the interrupt bit and error bit in the Status Register. (3) The software sends the DMA instruction to the disk device. (4) Write 1 to

We all know that MySQL QueryCache (QC) is cache based on the SQL statements actually used. For a related SQL query, if it starts with select, its MySQL server will try to use QC for it. Each Cache is saved using SQL text as the key. SQL text is not processed before QC is applied. That is to say, as long as the difference between the two SQL statements is not the

Query_cache_type from 1 to 0, also not;2, even if query_cache_size = 0, but query_cache_type not 0, in the actual environment, may occur frequently waiting for query cache lock;3, at the beginning of the set Query_cache_type = 0, there is no way to dynamically enable in the run process again, the reverse can be. That is, the start is to enable query cache, in the process of shutting it down, but in fact will still occur waiting for query cache lock, and no real shutdown;Detailed testing process

. query_cache_size = 0 Taobao DBA's Soup said: When your database opens the query Cache (QC) feature, the database executes the SELECT statement with its results in the QC, and the next time the same select request is processed, the database results from the QC without having to query the datasheet. In this "cache is King" era, we always in different ways to ca

When you recently deployed a Microsoft TFS-based software lifecycle management platform to a customer, customers asked for high availability at the database tier, reducing the impact of software development on database server failures.The customer's existing domain is a Windows 2008-level enterprise domain that is built on Windows Server 2008. In order to comply with the security requirements of the customer enterprise domain, minimum permissions are required during the deployment of the databas

Generate file Shell script and Description:#!/bin/shfile1=$ (date +%y%m%d%h%m%s) #定义变量获取当前时间ALM_TYPE=BOSS4ZC #定义变量instance_id=62100408# Defining variablesstatus=major# Defining variablesAlm_info=mysql Standby Host Downtime 10.**.62.**, please deal with it in time. #定义变量alm_time=$ (date + '%y-%m-%d%h:%m:%s ') #定义变量File2= $INSTANCE _id. #定义变量file3=.alm# Defining variablesFile_name= $file 2$file1$file3# Defining variablesCd/nms/almd/data/

format The code for sending the ata_trim command is as follows. You need to put it into a module compiled with the kernel and call it through the value input of/proc/variable. If you are interested, you can discuss it together. int ata_trim(uint block, uint n_block){struct ata_queued_cmd *qc=NULL;struct ata_taskfile *tf =NULL; struct sg_table *table=kmalloc(sizeof(struct sg_table),GFP_ATOMIC);int rc=0, nents=1; //entry(sg list) number of scatter/ga

about 300 tables. A lot of other discussions about Ulimit please click here(this paragraph is controversial..) On the one hand, table cache (past?) Implementation is very inefficient--look for a linear scan to complete. Therefore, setting Table_cache to thousands of does make MySQL slow. (The benchmark test also proves this point.)You can passSHOW GLOBAL STATUS;View the performance information of the system and calculate the number of open per second (Opens/second): Opened_files/uptime, assumin

or unlock function. MongoDB uses the "entity" of the database as the lock. There is an important database config in MongoDB sharding cluster, There are two collection and distributed locks in this db. One is config.locks. Mongos> Db.locks.find (). Pretty () {"_id": "Configupgrade", "process": "i-qikzt805:50000:1390191129:18042 89383 "," state ": 0," ts ": ObjectId (" 52dca219420e5e3bb3e63ee9 ")," when ": Isodate (" 2014-01-20t04:12: 09.751Z ")," who ":" i-qikzt805:50000:1390191129:1804289383:m