Question:
Explian rowid,rownum?What are the pseduocolumns we have?
Answer:
ROWID - Hexa decimal number each and every row having unique.Used in searching
ROWNUM - It is a integer number also unique for sorting Normally TOP N Analysys.
Other Psudo Column are
NEXTVAL,CURRVAL Of sequence are some exampls
Source: CoolInterview.com
ROWID : It gives the hexadecimal string representing the address of a row. It gives the location in database where row is physically stored. ROWNUM: It gives a sequence number in which rows are retrieved from the database. Source: CoolInterview.com
Answered by: jyothsna | Date: 2/25/2008
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ROWID : Every record in a database is uniquely identified by system generated value called Rowid. It Is a 18 character hexma decimal value. These Rowid's are physically existence.
ROWNUM : It is a pseduocolumn which generates the sequence of numeric values based on the position of the records in the output. These ROWNUM'S logically generated.
NEXTVAL,CURRVAL,SYSDATE,LEVEL ARE PSEDUOCOLUMNS Source: CoolInterview.com
Answered by: Satyanarayana Reddy velagala | Date: 12/22/2009
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ROWID : It gives the hexadecimal string representing the address of a row. It gives the location in database where row is physically stored. ROWNUM: It gives a sequence number in which rows are retrieved from the database.
Posted by: jyothsna
Contact jyothsna Contact jyothsna
ROWID : Every record in a database is uniquely identified by system generated value called Rowid. It Is a 18 character hexma decimal value. These Rowid's are physically existence.
ROWNUM : It is a pseduocolumn which generates the sequence of numeric values based on the position of the records in the output. These ROWNUM'S logically generated.
NEXTVAL,CURRVAL,SYSDATE,LEVEL ARE PSEDUOCOLUMNS Source: CoolInterview.com
Answered by: narendra | Date: 5/9/2010
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rowid gives the unique value for every record that has been inserted,which acts like an address to the location of the record in the database. rownum gives the unique value for every record that is selected from the database table. Source: CoolInterview.com
Answered by: satyanarayana | Date: 9/9/2010
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