Extraction, Transformation, and Loading - Data Warehouse Systems: Design and Implementation - page 292

Table 8.1 (continued)

Insert Data: inserts tuples into a database corresponding to records in the flow
Database Name of the database
Table Name of the table
[Mappings] List of Col- > Attr, where column Col in the input flow is mapped
to attribute Attr in the database
[Options] Either Empty or Append depending on whether the table is emp-
tied before inserting the new tuples, the latter is the default
Join: computes the join of two flows
Condition List of Col1 op Col2, where Col1 belongs to the first input flow,
Col2 to the second flow, and op is a comparison operator
[Join Type] Either Inner Join, Left Outer Join,orFull Outer Join, the first one
is the default
Lookup: adds columns to the flow obtained by looking up data from a database
Retrieve List of column names added to the output flow
Database Database name
Table | Query Name of the table or SQL query
Where List of column names from the input flow
Matches List of attribute names from the lookup table or SQL query
Lookup: replaces column values of the flow with values obtained by looking up
data from a database
Replace

List of column names from the input flow whose values are re-
placed in the output flow

Database Database name

Table Query Name of the table or SQL query

Where List of column names from the input flow
Matches List of attribute names from the lookup table or description of
an SQL query
Multicast: produces several output flows from an input flow
Input

|

List of column names from the input flow

Output* List of column names from each output flow. Output* is used

if the column names are the same for all flows, otherwise
Output1 ,..., Outputn are used, each flow defining the column

names
Remove Duplicates: removes duplicate records from the flow
(None) This task does not have any annotation
Rename Column: changes the name of columns from the flow
Columns NewCol where column Col from the input flow is

renamed NewCol in the output flow
Sort: sorts the records of the flow
Columns List of colum names from the input flow, where for each of them,
either ASC or DESC is specified, the former being the default
Union: computes the union of two or more flows
Input*

List of Col- >

List of column names from each input flow. Input* is used if the
column names are the same for all flows. Otherwise Input1, ... ,

Inputn are used, each flow defining the column names
Output List of column names from the output flow
[Keep Duplicates] Either Yes or No, the former is the default