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 VALUESclause 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 datafile 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 parallelimport 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. OracleData 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.
