unused ssn

database. 95% of database performance problems can be solved by indexing technology.1. Do not index small tables that are commonly usedDo not set any keys for small data tables, even if they are frequently inserted and deleted. Index maintenance on these insert and delete operations can be more time consuming than scanning the table space.2. Do not select a social Security number (SSN) or identification number (ID) as the keyNever use

data type that you are basing on, and the nullability of the data type.(1) Create a user-defined data typeYou can use Transact-SQL statements to create user-defined data types. System stored procedures sp_addtype can be used to create user-defined data types. Its grammatical form is as follows:sp_addtype {type},[,system_data_bype][, ' null_type ')Where type is the name of the user-defined data type. System_data_type are system-supplied data types, such as Decimal, Int, Char, and so on. Null_typ

, and to ensure that the columns have the same data type, length, and nullability. For example, you can define a data type called Postal_Code, which is based on the Char data type.When you create a user-defined data type, you must provide three numbers: the name of the data type, the system data type that you are basing on, and the nullability of the data type.1) Create a user-defined data typeYou can use Transact-SQL statements to create user-defined data types. System stored procedures sp_addt

Pm_user (NAME), Oracle also assigns a segment to the index, but this is an index segment. The information for a query segment can be obtained from the data dictionary: SELECT * from User_segments, (4) Tablespace: Contains segments,Areas and blocks. The data in the tablespace is physically stored in the data file in which it resides. A database must have at least one tablespace. OK, we're back to HWM now, so what's a high water mark? This is related to Oracle's space management. A Oracle uses HW

When compiling a program, there are a lot of warnings that are always unpleasant. Other people's code will endure, not good to change. My own can not endure. See how C + + eliminates wunused warnings.First look at the following program:#include int main (int argc,Char * *argv) {int A; return 0 ;}When compiling, turn on all warnings:[Email protected]:~/code/test$ g++-g-w-wall-o unused unused.cunused.c:in function 'intMainint,Char**) ': unused.

Set and delete unavailable columns in Oracle. 1. What are unavailable columns? That is, one or more columns in the table are ALTERTABLEhellip; The SETUNUSED statement is set to program Set and delete unavailable columns in Oracle. 1. What are unavailable columns? That is, one or more columns in the table are ALTER TABLEhellip; the set unused statement is SET to program Setting and deleting unavailable columns in Oracle 1. What is an unavailable c

, HWM information, and so on.2.2 Free list ConceptThe free list is a one-way list used to locate blocks that can receive data, and in a dictionary-managed table space, Oracle uses free list to manage unallocated storage blocks. Oracle logs blocks with free space for insert or update. Free space comes in two ways: 1. All blocks over HWM in the segment have been assigned to segments, but have not yet been used. 2. All the blocks under HWM in the paragraph that are linked into the free list can be

[Android's Beauty] APK slimming, reduce the size of the APK Keep your apk files as small as possible, and you should remove unused code and resource files. So this section describes how to make the apk smaller, better performance, the download conversion rate is higher, and how to specify the code and resources that are retained or removed during the build apk, before we have analyzed the apk size, there are some improper resource placement,

Analysis on the reason why the RMAN backup file is much larger than the database size When talking with the customer, the customer proposed that the database size is only 40 GB, but the file backed up by RMAN is 80 GB, And the DUMP file exported by expdp is less than 40 GB, I feel a little surprised. Isn't RMAN only backing up data blocks? How can backup not exceed 40 GB? Is it related to the high level line? With these questions, I read some articles on MOS and found that there is indeed a poss

=> l_total_blocks, Total_bytes => l_total_bytes, Unused_blocks => l_unused_blocks, Unused_bytes => l_unused_bytes, Last_used_extent_file_id => l_lastusedextfileid, Last_used_extent_block_id => l_lastusedextblockid, Last_used_block => l_last_used_block ); P ('total blocks ', l_total_blocks ); P ('total bytes ', l_total_bytes ); P ('unused blocks ', l_unused_blocks ); P ('unused bytes ', l_unused_bytes ); P

> select group #, members, status from v $ log; GROUP # MEMBERS STATUS ------------------------------------ 1 3 CURRENT 2 3 UNUSED 3 3 CLEARING 4 2 INACTIVE SQL> select group #, members, status from v $ log; GROUP # MEMBERS STATUS ------------------------------------ 1 3 CURRENT 2 3 UNUSED 3 3 UNUSED 4 3 CLEARING SQL> select group #, members, status from v

functionality. This means that even if you use common code to validate OrderID and SSN, they will not be the same. The use of common code to implement two different functions, in fact, is to approximate the two of these features are always bundled together, if OrderID changed its format, SSN verification code will be interrupted. Therefore, use this combination with caution, and do not arbitrarily bundle s

to maintain. But do not abuse this one, repetition does not mean the repetition of the code, but the repetition of the function. For example, you have the same code to verify OrderID and SSN, but they represent different meanings. If you merge two different functions together, when OrderID changes the format, then the code that examines the SSN is invalidated. So be aware of this coupling, and don't say an

IntroductionThe Netstat command is used to display various network-related information, such as network connections, routing tables, Interface states (Interface Statistics), masquerade connections, multicast members (multicast memberships), and so on.output message meaningAfter executing the netstat, the output isActive Internet connections (w/o servers) Proto recv-q send-q Local address Foreign address statetcp 0 2 210.34.6.89:telnet 210.34.6.96:2873 establishedtcp 296 0 210.34.6.89:1165 210.34

Brief introductionThe Netstat command is used to display various network-related information, such as network connections, routing tables, Interface states (Interface Statistics), masquerade connections, multicast members (multicast memberships), and so on. Output information meaningAfter the Netstat is executed, its output is Copy Code code as follows: Active Internet connections (w/o servers) Proto recv-q send-q Local address Foreign TCP 0 2 210.34.6.89:telnet 210.34.6.96:2

The example in this article describes the Java implementation method for sending mail based on SMTP. Share to everyone for your reference. The implementation method is as follows: Import Java.util.Date; Import java.util.Properties; Import Javax.mail.Authenticator; Import Javax.mail.Message; Import javax.mail.PasswordAuthentication; Import javax.mail.Session; Import Javax.mail.Transport; Import javax.mail.internet.InternetAddress; Import Javax.mail.internet.MimeMessage; Import Org.apache.lo

so on. State Diagram objects have behavior and status. The state of an object is determined by the current action and condition of the object. The state diagram Statechart diagram shows the possible state of the object and the transitions caused by the state change.Our model diagram establishes a bank's online login system. The login process involves entering a valid password and personal account and submitting it to the system for verification information. The login system can be divided into

192.0.0.8:139 time_wait TCP 192.0.0.9:1169 202.130.239.159:80 established TCP 192.0.0.9:1170 202.130.239.133:80 time_wait C:/Documents and Settings/bigball>netstat-a Active connections Proto Local Address Foreign TCP Liumy:echo liumy:0 Listening TCP Liumy:discard liumy:0 Listening TCP Liumy:daytime liumy:0 Listening TCP LIUMY:QOTD liumy:0 Listening TCP Liumy:chargen liumy:0 Listening TCP Liumy:epmap liumy:0 Listening TCP Liumy:microsoft-ds liumy:0 Listening TCP liumy:1025 liumy:0 Listening TCP

! Exit Please close this window directly.Pause@echo offEcho Info: Start testing whether the wireless network card supports the hosting networkNetsh wlan show driversecho Info: Please wait 3 secondsecho Set ws = CreateObject ("Wscript.Shell") >sleep3.vbsEcho Wscript.Sleep 3000>>sleep3.vbsSleep3.vbsDel Sleep3.vbsecho Info: Please check the above information to see if there is a "supported hosting network: Yes", if yes, continue, otherwise close this window.echo Info: Press ENTER to start building

vulnerable connections (that is, passwords) for authentication systems. The industry is in great need of technology that can replace passwords. With embedded cryptographic processors, smart cards provide a very secure and easy-to-use authentication mechanism. However, the deployment of smart cards also poses a unique challenge. The entire industry needs better products to deploy and manage complex authentication technologies. In his keynote address at the RSA 2006 Conference, Bill Gates demons