How to calculate the computing power of server SQL statements

1. When the number of users is large and the amount of concurrency is large, code calculation is good, which is equivalent to
distributed computing
, which can rece the computing pressure of the server. On the contrary, let the server use
sql statement
to calculate.

2.

I've only used MS SQL server, but I haven't tested the others

< pre t = "code" L = "SQL" > select * fromopen rowset (# 39; SQLOLEDB',&# 39; Server IP address&# 39; Database user name&# 39; Database password;, Database name. Dbo. Table name) < / pre >

3. You haven't learned SQL at all<
select the target you want to search
from the database file
where you want the conditional restrictions of the target
I suggest you take a look at the book in this area
and then study it yourself

4. (1) Start monitoring
lsnrctl start< (2) enter the sqlplus interface
sqlplus / nolog
sql & gt; conn sys/ jiaxiaoai@orcl as sysdba;
(3) start the database instance
sql & gt; startup;
(4) view all current databases
select * from V $database
or select name from V $database
(5) check which users have SYSDBA and sysoper permissions
select * from V_$ PWFILE_ USERS< br /> show user View the current database connection user
(6) enter a database: database name
View database structure: desc V $database
(7) view all user instances:
select * from V $instance
or select instance_ name from v$instance;
(8) view all data tables of the current library
select * from all_ tables;< br /> select table_ name from all_ tables;< br /> select table_ name from user_ tables;< br /> select table_ name from all_ tables where owner=' User name & # 39
(9) view the table structure
desc table name;

5. How to export data from the MySQL database on the server to the local with SQL statements
purpose: the database of the remote server to the local
java code
the code as follows:
mysqlmp
- H
& 39; 114.212.111.123'
- urose
- pxxooo
-- opt
-- compress
ITSM
-- skip lock tables
|
MySQL
- H
- localhost
- uroot
- prot
itsmc
explanation:
114.212.111.123
remote server name
rose
remote database login name
rxxooo
remote database login password
ITSM remote database name (i.e Copy source)
localhost
local database name (usually this)
root
local database login name (usually this)
root
local database login password (generally this)
itsmc
local (that is, the purpose of )
sql explanation:
mysqlmp
is a special part of MySQL The command used for operation
-- opt
operation means
-- compress
compress the data to be transmitted
-- skip lock
ignore the locked table (plus this sentence can prevent errors when the table has a foreign key)
- tables
all tables in a database
- H
server name
- U
user name (* no space after, Add user name directly)
- P
password (* without space, add password directly)
note:
- u, - P without space, add user name and password directly!!!

6. [method 1] view the port number of SQL Server 2005 with SQL statements
to view the port number of SQL Server 2005, we can find it on the machine where SQL Server service is installed through the configuration tool SQL Server Configuration Manager (SSCM). If the SQL server is remote, this method will not work. However, we can also view it by looking at the SQL server server logs. If there is a lot of content in the log, it will be troublesome to find it. Fortunately, SQL Server 2005 provides us with a very useful system stored procere sp_ readerrorlog You may not find it in the SQL Server help documentation). To get back to the point, the following demonstration shows how to find the SQL server port number through SQL statements:
exec sys.sp_ readerrorlog 0, 1, ' listening'
logdate processInfo text
SQL Server 2005 system extended stored procere sys.readerrorlog can read SQL server log file. Note that the log file here refers to the SQL server log, not the log file of the SQL Server database Method 2]
click Start - Microsoft SQL Server 2005 - configuration tool - SQL Server Configuration Manager - expand network configuration - click mysqlserver protocol - double click TCP / IP - select IP address to see the port number

7. In the query analyzer

8. For example, Oracle can create dblink to query, such as local query table: select * from table
dblink: select * from table@dblink name

9. Server is a computer, but it has a strong pressure bearing capacity, operation logic and so on. It is used to calculate, compile, receive data and return data to users. It is an abstract vocabulary

10. 1] The following statement about IP datagram is wrong____ D____ A. The format of IP datagram is regulated by IP protocol. B. IP datagram is independent of various physical network data frame formats. C. IP datagram includes two parts: header and data area. D. the size of IP datagram is fixed to 53 bytes. PC I / O interface can be divided into many types, which can be divided into three types according to different data transmission modes____ Serial____ And parallel interface[ 3] In computer network, users can share information on other computers as long as permission is allowed__ Software Hardware and data resources[ 4] Common word processing software such as WPS, Microsoft Word, PDF writer, etc. have rich text editing and typesetting functions x) [5]. All the hosts in the LAN are connected to a shared transmission medium, so the hardware and software resources of any computer in the network are unconditionally shared by other computer users in the network x) [6]. The minimum data unit of a read-write operation on a PC hard disk is_____ B___ A. 1 binary bit B. 1 byte C. 1 word D. 1 sector [8]. Logic plus common symbols in logic operation____ A____ express. A. The radio wave can be divided into medium wave, short wave, ultrashort wave and microwave according to the frequency, and the one with the highest frequency and propagating in a straight line is__ Short wave[ 10] . in the functions listed below__ B__ Functionality is not part of the operating system. A. CPU management b. cost management C. file management D. storage management [11]. Integrated circuit is the foundation of modern information instry. At present, the integrated circuit used in CPU chip of PC belongs to____ C___ A. Small scale integrated circuits B. medium scale integrated circuits C. large scale integrated circuits D. very large scale and very large scale integrated circuits [12]___ C_____ A. FTP service cannot be started by using IE browser. B. FTP can only transfer one file at a time. C. users can download (upload) files from (to) FTP server. D. FTP program does not allow users to create new folders on FTP server__ A___ A. Computer system with multiple processors B. computer system with multiple central processors C. computer system with pipeline processing technology D. computer system with multiple ALUs in the arithmetic unit [14]. Among the following devices, the options that belong to image input devices are____ A______ A. Digital cameras, scanners B. plotters, scanners C. digital cameras, projectors D. digital cameras, graphics cards [15]. A computer often has multiple processors, which undertake different tasks. The processor that undertakes the task of running system software and application software is called____ CPU____ Processor, which is the core component of computer[ 16] . in____ B____ Compared with other common transmission media, optical fiber does not have obvious advantages. A. No electromagnetic interference B. price C. data transmission rate D. confidentiality [17]. The main performance indicators of the scanner are resolution, color bits, etc. The more color bits, the richer colors the scanner can reflect, and the more realistic the scanned image effect is (right) [18]. Windows system supports the use of long file names, and users can define file names of any length for files x) [19]. A hyperlink in a web page consists of a chain source and a chain sink. The chain source can be a text or an image in a web page, and the chain sink can be a place marked with a bookmark inside the web page, or an information resource stored on other web servers [20]. The operating system suitable for installing on the server is_____ B___ A. Windows MEB. Windows NT server C. Windows 98 sed. Windows XP [21]. The communication line of telephone communication system is used to transmit voice signal, it can not be used to transmit data 10) [22]. In the campus network, the network can be set, so that the IP address outside the school can not directly access the campus website The I / O operations of different I / O devices are often carried out in parallel x) [24]. The Chinese meaning of ASCII code, which is widely used in computers, is____ c____ A. Binary code B. commonly used character code C. American standard information exchange code D. Chinese national standard code [25]. In the radio broadcasting system, a radio can listen to multiple different radio programs, and the channel multiplexing technology adopted is___ a______ Multiplexing. A. Frequency division B. time division C. code division D. wavelength division [26]. About the CMOS chip on the PC motherboard, the following statement is correct____ d____ A. CMOS chip is used to store configuration parameters of computer system, which is read-only memory. B. CMOS chip is used to store power on self-test program. C. CMOS chip is used to store BIOS, which is volatile. D. CMOS chip needs a battery to supply power to it, otherwise the data in it will be lost when the host power is off, Every computer must have a unique____ ip____ Address[ 28]. The figure below is the schematic diagram of a PC motherboard, in which (1), (2) and (3) are respectively. A. I / O interface, AGP slot and IDE interface B. IDE interface, CPU slot and AGP interface C. I / O interface, CPU slot and memory slot D. I / O interface, IDE interface and AGP slot [29]_____ c___ Transmission and exchange for the unit. A. File B. byte C. packet D. record [30]. The two main steps of using computer to generate scenery image are___ d_______ A. Scanning, sampling, B. drawing, modeling, C. sampling, a / D conversion, D. modeling, drawing [31]. Information is a basic resource for people to understand and transform the world In physical structure, the main memory is composed of memory moles inserted on the main board, and the memory chips on the memory moles generally use DRAM instead of SRAM For [33]. When decimal number-31 is represented by 8-bit (including sign bit) complement, its binary code is__ 11100001______[ The first generation computers were mainly used in scientific and engineering calculation. It uses machine language and assembly language to write programs There are two main types of displays used by computers: CRT and CRT___ led_____ Monitor[ Programming languages can be divided into machine language, assembly language and high-level language, among which high-level language is close to natural language and easy to learn, use and modify The compiler or interpreter of a programming language belongs to___ b_____ A. System software B. application software C. real time system D. distributed system [38]__ d______ A. The sequential structure takes up more storage space than the link structure. B. compared with the link structure, the sequential structure is more concive to the insertion and deletion of elements. C. the sequential structure is easier to expand space than the link structure. D. the sequential structure takes up continuous storage space, while the link structure does not require continuous storage space____ c____ Three kinds of control structure, you can write any complex computer program. A. Rotor (program), return, process B. input, output, process c. sequence, select, repeat D. I / O, transfer, cycle [40]____ Arithmetic unit____ It consists of a register and a register[ The general external modem should be connected to the computer___ Serial port_____ Interface[ 42]. In the following description of network information security, what is correct___ c_____ A. The information with digital signature is undisclosed. B. the firewall can prevent the outside world from contacting the internal network, so as to ensure the absolute security of the internal network. C. The purpose of digital encryption is to ensure the data security even when the network communication is eavesdropped. D. using good anti-virus software can kill all viruses. The wireless interface keyboard is a relatively new keyboard, which is easy to use, It is mostly used for portable PC. what is wrong in the following description of wireless keyboard____ a____ A. The input information is directly input into the computer without I / O interface, so it is faster. B. the wireless keyboard is more flexible and convenient to use. C. when using the wireless keyboard, a special receiver must be installed on the host. D. the wireless keyboard has the function of a general keyboard___ c__ And DVD recorders. A. Dvd-rwb. Dvd-ramc. Dvd-romd. DVD-R [45]. The functions of instructions are different, and the execution steps of instructions are also different, but the steps that must be experienced to execute any instruction are as follows__ a___ A. Take instruction and instruction decoding B. add operation C. save operation results to memory D. read operation number 2 from memory. Choose basic knowledge to do questions [1]. In the real world, the voice that can be heard by human ear has a wide bandwidth, which can reach 20Hz ～_____ 20___ KHz, commonly known as full band sound[ 2] Computer information system is a kind of data intensive application system___ b______ A. Most of the data should be kept for a long time. B. the computer system uses memory to keep the data. C. The data can be shared by multiple applications. D. the data pattern is oriented to the global application of the system___ d_______ A. The result of relational operation is also relational B. the primary key of relational schema is an attribute group of the schema C. The structure of relational model is a two-dimensional table D. relational model and relational schema are two identical concepts [4]. In the student achievement management system, there is a student table s, whose mode is s (s #, sname, sex, age). Now to query the relevant information of all male students, you need to use SQL___ Select * from TXL where statement (only SQL statement identifier)[ 5] The following statement about the sound card is correct____ d_____ A. The sound card in the computer can only process waveform sound, but not MIDI sound. B. converting sound wave into electrical signal is one of the main functions of the sound card. C. the sound wave is converted into digital signal by microphone, and then transmitted to the sound card for data compression. D. with the development of large-scale integrated circuit technology, At present, the sound card of most PC has been integrated with the main board [6]___ d_____ A. Computer aided design B. computer aided manufacturing C. material requirement planning system D. Enterprise Resource Planning [7]. Some cities in China have opened the cable digital TV service, but at present most of the newly purchased TV sets can not directly support the reception and broadcasting of digital TV The abbreviation of data flow chart is____ c____ A. DDB. Casec. Dfdd. CAD [9]. The information system starts from planning, through analysis, design, implementation and put into operation, and is constantly modified with the change of its living environment in the process of use, until it is eliminated when it no longer meets the needs. This time process is called information system development__ Life cycle[ 10] SQL language has the functions of data definition, data operation and data control. The result of a query can only be a tuple x) There's a problem I didn't give a picture. Sorry, I don't know.