Oracle performance optimization operation 12: Use Case statements to merge multiple scans, oraclecase
We often have to calculate different aggregation based on multiple sets of data tables. For example, the following example uses three independent queries:
Select count (*) from emp where sal
In this way, we need to perform three full table queries, but if we use the case statement:
Select count (sale when sal
In this way, the query results are
=requests.get ('/ http'+address,headers=header) the theOriginal_match=re.search (R"", R.content) the thethreads=[] - forIinchRange (254): inThreads.append (Threading. Thread (target=loop,args=(R,cip,original_match,header))) the forTinchThreads: the T.start () About the if __name__=='__main__': theStart ()1, because it is multi-threaded, output when the print xxx will appear due to thread preemption caused by the output of the chaos, instead of using print xxx+ ' \ n ', can n
A long time ago, when we were writing SQL, one of the things we feared most was the super slow of SQL, the slow way to get a pipe back, the ball was still spinning ... This worry only the parties understand, and later heard that there is a "evaluation of the Implementation Plan", later later understand should avoid table scan ...
One: Table scan
1. The phenomenon
"Table Scan" sounds simple, not just a line of sweep, you have to say "implementation plan", I will play, in order to more impressi
There will be two choices at this time:
1. Scan and repair (recommended)
2, continue, but do not scan
Extremely warning
When you're sure you have important information in your USB flash drive, don't point. First option: Scan and
1382-distant Galaxy
Time limit:3.000 seconds
Http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=460&page=show_ problem&problem=4128
You are are observing a distant galaxy using a telescope above the astronomy Tower, and
1. A4 paper that needs to be scanned.2. Optical scanning bracket.3. I8580 mobile phone.
Step 2. Placing the device in a specified position
Mobile phone and A4 paper placement method as shown in the following figure:
Step 3. Scan A4 Paper
Let's introduce two functions:
One. Os.walk () can get a ternary tupple (Dirpath,sub_dirs, filenames), where the first is the starting path, the second is the folder under the starting path, and the third is the file under the starting path.Where
SQL scan and execute SQL script in folderScenario: The project database operations are all implemented using stored procedures. There are a lot of updates/additions to the stored procedures every day, manual updates to the stored procedures in the
Ten common nmap scanning commands and ten nmap scansTen common nmap scanning commands
NMap is also known as Network Mapper. nmap is a powerful scanner that is often used in Network security penetration testing. It has powerful functions and is
This time this really is dry goods oh, last night made a half night,,,, from 8 points after eating dinner began to write, has been nearly 12 o'clock to finish,,, novice, can't afford to hurt Ah ....First of all, Baidu provides a music search API,
This example for you to share the PHP Web generated two-dimensional code, Android client scan login specific code for your reference, the specific content as follows
Using the Zxing open Source Library with sweep code on the GitHub, the network API
First, the preface
Originally thought so easy, really did not think, also made a while, make me sweating, want to clap table slam keyboard.The features you want to implement are:Through NetEase cloud Music/Baidu Music/qq Music/Cool dog music in an
1, the Windows system under the Implementation folder file scanning
The implementation code is as follows:
#include #include #include #define Testfolderpath "./" void Scanfolder (c
Onst char* Folder_path);
int main (int argc,char* argv[])
When you access the Internet, you often find that the network firewall keeps issuing alarms, which may be caused by hacker attacks. Here we will introduce you to some ways to get rid of these attacks.
1. Cancel folder hiding and sharing
If you use
1. Low Efficiency of fuzzy search:
Cause: Like itself is relatively inefficient. You should try to avoid using like in query conditions; for like '%... % '(Full fuzzy) is a condition where indexes cannot be used. Full table scan is naturally
Reprint Please note: @ small Wuyi: http://www.cnblogs/xiaowuyi
After scapy is installed (the first two notes are described), run sudo scapy in linux.1. Simple sending package
1. send () sends data packets on the third layer, but does not receive
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