Which of the following can be used to populate a table? Each correct answer represents a complete
solution. Choose all that apply.
A.
Data Pump
B.
SQL*Loader
C.
INSERT statement
D.
MERGE statement
Explanation:
The INSERT statement is a Data Manipulation Language (DML) statement that is used to add new
rows of data to a specified database table.
Syntax:
INSERT INTO TableName [ (ColumnName [, ColumnName…] ) ]
VALUES ( value [, value…] );
where,
TableName specifies the name of the table.
ColumnName specifies the name of the column of the table, which is to be populated.
value specifies the value for the corresponding column of the table.
The number and datatypes of values specified in the VALUES clause must match the number and
datatypes of corresponding columns specified in the INTO clause. If the columns are not specified,
the values in the VALUES clause must be in the order in which the columns are defined in the table.
SQL*Loader (sqlldr) is a utility that is used for high performance data loads. The data can be in the
form of a text file or embedded into a database. By using the information stored in the data file and
the control file, sqlldr loads the data into a database. The architecture of SQL*Loader is given below:In the figure, 1 depicts the parameter file, 2 depicts the data file, 3 depicts the control file, 4 depicts
the log file, 5 depicts the bad file, and 6 depicts the discard file.Note: While processing the
information, SQL*Loader stores messages in the log file, bad rows in the bad file, and discarded rows
in the discard file. Data Pump is a new feature introduced in Oracle 10g to move data and meta data
between databases and to or from operating system files very efficiently. It provides parallel import
and export utilities (impdp, expdp) on the command-line as well as the Web-based Oracle Enterprise
Manager export/import interface. It is ideally beneficial for large databases and data warehousing
environments. Oracle Data Pump facility runs on the server.
Following are some functions performed by Oracle Data Pump:
1.It is used to copy data from one schema to another between two databases or within a single database.
2.It can be used to extract a logical copy of the entire database, a list of tablespaces, a list of
schemas or a list of tables. The MERGE statement is a Data Manipulation Language (DML) statement
that is used to update or insert rows conditionally into a table. It selects rows from one table and
updates or inserts them into another table. The decision whether to update or insert rows in the
target table is based on a condition in the ON clause of the MERGE statement.
