informatica tips 1

8/17/2019 Informatica Tips 1

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Rules and Guidelines for Connecting Mapping Objects

If the Designer detects an error when you try to link ports between two mapping objects,it displays a symbol indicating that you cannot link the ports.

Consider the following rules and guidelines when you connect mapping objects:

• Follow logic of data flow in the mapping. Gien the logic of the data flow

between sources and targets, you can link the following types of ports:

o !he receiing port must be an input or input"output port.

o !he originating port must be an output or input"output port.

o #ou cannot link input ports to input ports or output ports to output ports.

• #ou must link at least one port of an input group to an upstream transformation.

• #ou must link at least one port of an output group to a downstream

transformation.

• #ou can link ports from one actie transformation or one output group of an

actie transformation to an input group of another transformation.• #ou cannot connect an actie transformation and a passie transformation to the

same downstream transformation or transformation input group.

• #ou cannot connect more than one actie transformation to the same downstream

transformation or transformation input group.

• #ou can connect any number of passie transformations to the same downstream

transformation, transformation input group, or target.

• #ou can link ports from two output groups in the same transformation to one

$oiner transformation configured for sorted data as long as the data from both

output groups is sorted.

• #ou can only link ports with compatible datatypes. !he Designer erifies that it

can map between the two datatypes before linking them. !he %owerCenter &erercannot transform data between ports with incompatible datatypes. 'hile the

datatypes do not hae to be identical, they do hae to be compatible, such as Charand (archar. For a list of compatible datatypes

• #ou must connect a source definition to a source )ualifier only. *ery source must

connect to a source )ualifier or +ormalier transformation. #ou then link the

source )ualifier or +ormalier to targets or other transformations.

• #ou can link columns to a target definition in a mapping, but you cannot copy

columns into a target definition in a mapping. -se the 'arehouse Designer to add

columns to a target definition.

'hen you edit a port name in a transformation, by default, the Designer propagatesreferences to that port in the epressions, conditions, and other ports in that

transformation. #ou can also propagate changed attributes throughout the mapping.

!he Designer propagates ports, epressions, and conditions based on the following

factors:


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• -pdates the associated port property in a dynamic 3ookup transformation if the

associated port name changes.

• -pdates the port name of Custom transformation port dependencies.

#ote$ 'hen you propagate a port name, the Designer appends 415 to the port name if a

port with the same name already eists in the transformation.

%&a!ple

&uppose you hae the following mapping:

!he 6!# port in the $oiner transformation links to the 6!# port in the 2ggregator

transformation. !he 2ggregator transformation references the 6!# port in theepressions for !7!2386-2+!I!# and !7!2389*(*+-*.

#ou make the following changes to the 6!# port in the $oiner transformation:

• #ou change the port name 6!# to 6-2+!I!#.

• #ou change the datatype from Decimal to Integer.

'hen you propagate forward the attributes, the Designer updates the followingdependencies in the 2ggregator transformation:

• !he Designer updates 6!# port name to 6-2+!I!#.

• !he Designer updates the reference to 6!# port name in the epressions for the

!7!2386-2+!I!# and !7!2389*(*+-* ports change to 6-2+!I!#.• !he Designer updates the datatype of 6!# port name to Integer.

"ropagating !plicit Dependencies

#ou can propagate datatype, precision, and scale to ports with implicit dependencies.

'hen you click 7ptions in the %ropagate %orts dialog bo, you can choose to parse


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conditions and epressions to identify the implicit dependencies of the propagated port.

2ll ports with implicit dependencies are output or input"output ports.

'hen you choose to include conditions the Designer updates the following dependencies:

•

3ink path dependencies.• 7utput ports used in the same lookup condition as the propagated port.

• 2ssociated ports in dynamic 3ookup transformations that are associated with the

propagated port. For more information about associated ports, see 43ookup!ransformation5 in the Transformation Guide.

• 7utput ports used by a Custom transformation to define a port relationship with

one or more input or input"output ports. For more information about defining port

relationships, see 4Custom !ransformation5 in the Transformation Guide.

• aster ports used in the same join condition as the detail port.

'hen you choose to include expressions, the Designer updates the following

dependencies:

• 3ink path dependencies.

• 7utput ports containing an epression that uses the propagated port.

%&a!ple

&uppose you hae the following mapping:

!he 2+-F2C!-9*98ID port in the 2ggregator transformation links to theI+82+-F2C!-9*98ID port in the 3ookup transformation. !he 3ookup

transformation uses the following lookup condition:

2+-F2C!-9*98ID ; I+82+-F2C!-9*98ID


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#ou change the datatype of the 2+-F2C!-9*98ID port from integer to decimal in

the 2ggregator transformation. #ou choose to parse conditions to infer dependencies, and

then propagate the datatype change. !he Designer performs the following tasks:

• Updates link path dependencies. !he Designer updates the ports in the link path,

changing the datatype of the I+82+-F2C!-9*98ID port in the 3ookuptransformation to decimal.

• dentifies dependent ports. !he Designer parses the lookup condition and

identifies the 2+-F2C!-9*98ID port in the 3ookup transformation as a

dependent port.

• Updates i!plicit dependencies. !he Designer changes the datatype of the

2+-F2C!-9*98ID port in the 3ookup transformation to decimal.

"ropagated 'ttributes by Transfor!ation

!able /01 describes the dependencies and attributes the Designer propagates for each

transformation:

!able /01. %ropagated 2ttributes by !ransformation

Transfor!ation Dependency "ropagated 'ttribute

2ggregator

• %orts in link path

• *pression

• Implicit dependencies

• %ort name, datatype,

precision, scale

• %ort name

• Datatype, precision,

scale

2pplication &ource6ualifier

• %orts in link path• %ort name, datatype,

precision, scale

Custom


• %ort dependency



precision, scale

• %ort name


scale

*pression


• *pression


• %ort name, datatype, precision, scale

• %ort name


scale

*ternal %rocedure • %orts in link path • %ort name, datatype,


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precision, scale

Filter


• Condition


precision, scale

• %ort name

Input • %orts in link path• %ort name, datatype,

precision, scale

$oiner


• Condition



precision, scale

• %ort name


scale

3ookup


• Condition

• 2ssociated ports


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General Rules and Guidelines

Consider the following rules and guidelines when you propagate port attributes:

• !he Designer does not propagate to implicit dependencies within the same

transformation.• 'hen you propagate backward along the link path, erify that the change does not

cause the %owerCenter &erer to fail the session. For eample, if you propagatechanges to a source )ualifier, the %owerCenter &erer might generate inalid &63

when it runs the session. If you change the port name 4C-&!8ID5 to

4C-&!7*98ID,5 the %owerCenter &erer might generate &63 to select thewrong column name if the source table uses 4C-&!8ID.5

• 'hen you propagate port attributes, erify that the change does not cause the

Designer to inalidate the mapping. For eample, when you change the datatype

of a port from integer to string and propagate the datatype to othertransformations, the Designer inalidates the mapping if a calculation uses one of

the changed ports. (alidate the mapping after you propagate ports. If the Designer inalidates the mapping, choose *dit09eert to &aed to reert to the last saedersion of the mapping.

• 'hen you propagate multiple ports, and an epression or condition depends on

more than one propagated port, the Designer does not propagate attributes to

implicit dependencies if the attributes do not match.

For eample, you hae the following epression in an *pression transformation:

Item8desc8out ; &ubstr


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!he Designer displays the %ropagate %ort 2ttributes dialog bo.

2fter you open the %ropagate %ort 2ttributes dialog bo, you can select another

port and propagate its attributes.

. &elect the direction and attributes you want to propagate.

E. 7ptionally, choose to infer dependencies.

!able /0. %ropagate %ort 2ttributes Dialog o

Option Re)uired*Optional Description

%reiew 7ptional

Displays the links to the

affected ports in green andthe unaffected ports in red.

%ropagate 9e)uired%ropagates the port attributesaccording to the options you

specify in the dialog bo.

Direction 9e)uired

Instructs the Designer to

propagate attributes forward, backward, or in both

directions.

2ttributes

to%ropagate 9e)uired

&pecifies the attributes that

you want to propagate. !he

attributes include name,datatype, precision, and

scale.

7ptions 7ptional &elect to read conditions or

epressions and propagateattributes to implicit

dependencies. !he Designer


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disables these options when

you propagate the port name.

!hese options are clear bydefault. 'hen you select one

of these options and click

%reiew, the Designerhighlights the link paths to

the dependent ports.

/. Click %reiew to iew the affected ports. !he Designer displays the links to the

affected ports in green and the unaffected ports in red.

A. Click %ropagate.

'hen you propagate port attributes, the 7utput window displays the propagatedattributes and the affected ports.

. Click Close.

'pplication (ource +ualifier transfor!ation. 9epresents data read from

2pplication sources.

,ML (ource +ualifier transfor!ation. 9epresents data read from ?3 sources.

2 transformation is a repository object that generates, modifies, or passes data. #ouconfigure logic in a transformation that the %owerCenter &erer uses to transform data.

!he Designer proides a set of transformations that perform specific functions. For

eample, an 2ggregator transformation performs calculations on groups of data.

*ach transformation has rules for configuring and connecting in a mapping.

#ou can create transformations to use once in a mapping, or you can create reusable

transformations to use in multiple mappings. 'hen you add a reusable transformation to

a mapping, you add an instance of the transformation. 'hen you edit the reusabletransformation in the !ransformation Deeloper, all instances of the transformation in

mappings inherit the changes. &ome changes might inalidate the mappings using the

reusable transformation.

#ou can build mapplets in the applet Designer when you want to use a standardied setof transformation logic in seeral mappings. 'hen you use a mapplet in a mapping, the

Designer creates an instance of the mapplet. !he mapplet instance displays only the ports

from the Input and 7utput transformations. !hese transformations display as groups. #oucan enter comments for the instance of the mapplet in the mapping, but you cannot edit

other mapplet properties.

Figure /01 shows the mapplet input and output groups in a mapping:


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Figure /01. applet Display in apping

#ou can epand the mapplet in the apping Designer by selecting it and choosingappings0*pand from the menu. !his epands the mapplet within the mapping for

iew. #ou can open or iconie all the transformations in the mapplet and mapping, butyou cannot edit any of the properties.

'hen you edit the mapplet in the applet Designer, all instances of the mapplet inmappings inherit the changes. &ome changes might inalidate the mappings using the

mapplet.

'hen you create a mapping, you must add one or more target definitions to it. 'hen youdrag a target definition into the apping Designer workspace, you add an instance of the

target definition.

'hen you add targets to a mapping, you can include different types of targets. #ou can

include targets of the same database type, but different database connections. #ou canalso include both relational and flat file targets in the same mapping.

'hen you edit the target in the 'arehouse Designer, all instances of the target in

mappings inherit the changes. &ome changes might inalidate the mappings using thetarget.

#ote$ 'hen you add a target definition with some special characters in the table name to

a mapping, the Designer replaces the character with an underscore in the target instance

name for the mapping.

#ou can configure properties for relational, file, and ?3 targets in a mapping.

Configuring Relational Targets in a Mapping

For relational targets, you can configure the following properties within a mapping:


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• Reject truncated and o-erflo data. &elect this option in the target instance

%roperties tab when you want the %owerCenter &erer to write truncated data to

the reject file.• Update o-erride. 7erride the default -%D2!* statement using the &63 *ditor

in the target instance %roperties tab.

•

Table na!e prefi&. &pecify the owner of the target tables in the target instance%roperties tab.

• "re/ and post/session (+L. #ou can enter pre0session &63 commands for a

target instance in a mapping to eecute commands against the target database

before the %owerCenter &erer reads the source. *nter post0session &63commands to eecute commands against the target database after the

%owerCenter &erer writes to the target.

Configuring 0lat 0ile Targets in a Mapping

For flat file targets, you can configure the following properties within a mapping:

• Dateti!e for!at. Define the default datetime format to use for datetime alues.

• Thousands separator. Define the default thousands separator to use for numeric

alues.

• Deci!al separator. Define the default decimal separator to use for numeric

alues.

Configuring ,ML Targets in a Mapping

For ?3 targets, you can change the root element. Howeer, if you change the root, you

affect the target ?3 structure and you can inalidate the mapping.

For more information about configuring ?3 targets in a mapping, see the XML User

Guide.

(etting the Target Load Order

#ou can configure the target load order for a mapping containing any type of target

definition. In the Designer, you can set the order in which the %owerCenter &erer sendsrows to targets in different target load order groups in a mapping. 2 target load order

group is the collection of source )ualifiers, transformations, and targets linked together in

a mapping. #ou can set the target load order if you want to maintain referential integrity

when inserting, deleting, or updating tables that hae the primary key and foreign keyconstraints.

Figure /01E illustrates two target load order groups in one mapping:

Figure /01E. !arget 3oad 7rder Groups


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!he %owerCenter &erer reads sources in a target load order group concurrently, and it processes target load order groups se)uentially.

!o specify the order in which the %owerCenter &erer sends data to targets, create one

source )ualifier for each target within a mapping. !o set the target load order, you then

determine in which order the %owerCenter &erer reads each source in the mapping.

!o set the target load order:

1. Create a mapping that contains multiple target load order groups.

. Choose appings0!arget 3oad %lan.

!he !arget 3oad %lan dialog bo lists all &ource 6ualifier transformations in the

mapping, as well as the targets that receie data from each &ource 6ualifier.

. &elect a &ource 6ualifier from the list.

E. Click the -p and Down buttons to moe the source )ualifier within the load order.

/. 9epeat steps and E for any other source )ualifiers you wish to reorder.


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A. Click 7>.

. Choose 9epository0&ae.

'hen you add a relational target to a mapping, you can configure the following

properties:

• Reject truncated and o-erflo data. &elect this option in the target instance

%roperties tab when you want the %owerCenter &erer to write truncated data to

the reject file.

• Update o-erride. 7erride the default -%D2!* statement using the &63 *ditor

in the target instance %roperties tab.

• Table na!e prefi&. &pecify the owner of the target tables in the target instance

%roperties tab.

• "re/ and post/session (+L. #ou can enter pre0session &63 commands for a

target instance in a mapping to eecute commands against the target database

before the %owerCenter &erer reads the source. *nter post0session &63commands to eecute commands against the target database after the%owerCenter &erer writes to the target.

#ote$ #ou cannot configure these properties in the 'arehouse Designer.

Figure /01/ shows the items you can configure on the %roperties tab of a relational target

definition in the apping Designer:

Figure /01/. 9elational !arget %roperties !ab in the apping Designer

Rejecting Truncated and O-erflo Data


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!he Designer lets you conert data by passing it from port to port. &ometimes a

conersion causes a numeric oerflow


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Figure /01 shows the default -%D2!* statement for the target !8&23*&:

Figure /01. -%D2!* &tatement for &ample apping

ecause the target ports must match the target column names, the update statement

includes the keyword :!- to specify the ports in the target transformation. If you modify

the -%D2!* portion of the statement, be sure to use :!- to specify ports.

O-erriding the 12%R% Clause

#ou can oerride the 'H*9* clause to include non0key columns. For eample, youmight want to update records for employees named ike &mith only. !o do this, you edit

the 'H*9* clause as follows:

-%D2!* !8&23*& &*! D2!*8&HI%%*D ; :!-.D2!*8&HI%%*D,!7!238&23*& ; :!-.!7!238&23*& 'H*9* :!-.*%8+2* ; *%8+2*

and

*%8+2* ; KI>* &I!HK

Rules and Guidelines

-se the following rules and guidelines when you enter target update )ueries:

• If you use target update oerride, you must manually put all database resered

words in )uotes.• #ou cannot oerride the default -%D2!* statement if the target column name

contains any of the following characters:

K , < = L M ; N 0 O " P t P n P @ LspaceM

• 'hen you sae a mapping, the Designer erifies that you hae referenced alid

port names. It does not alidate the &63.


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• If you update an indiidual row in the target table more than once, the database

only has data from the last update. If the mapping does not define an order for the

result data, different runs of the mapping on identical input data may result indifferent data in the target table.

• 2 'H*9* clause that does not contain any column references updates all rows in

the target table, or no rows in the target table, depending on the 'H*9* clauseand the data from the mapping. For eample, the following )uery sets the*%8+2* to KI>* &I!HK for all rows in the target table if any row of the

transformation has *%8ID M 1@@:

-%D2!* !8&23*& set *%8+2* ; KI>* &I!HK 'H*9* :!-.*%8IDM 1@@

• If the 'H*9* clause contains no port references, the mapping updates the same

set of rows for each row of the mapping. For eample, the following )uery

updates all employees with *%8ID M 1@@ to hae the *%8+2* from the last

row in the mapping:

-%D2!* !8&23*& set *%8+2* ; :!-.*%8+2* 'H*9* *%8ID M

1@@

• If your mapping includes an -pdate &trategy or Custom transformation, the

!arget -pdate statement only affects records marked for update.

• If you use the !arget -pdate option, configure the session to mark all source

records as update.

%ntering a Target Update (tate!ent

-se the following procedures to create an update statement.

!o enter a target update statement:

1. Double0click the title bar of a target instance.

. Click %roperties.

. Click the open button in the -pdate 7erride field.


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E. !he &63 *ditor displays.

/. &elect Generate &63.

!he default -%D2!* statement appears.

A. odify the update statement.

#ou can oerride the 'H*9* clause to include non0key columns.

*nclose all resered words in )uotes.

. Click 7>.

!he Designer alidates the &63 when you sae the mapping.

Table #a!e "refi&

!he table name prefi is the owner of the target table. For some databases, such as D,target tables in a session can hae different owners. If the database user specified in the

database connection is not the owner of the target tables in a session, specify the table

owner for each target instance. 2 session can fail if the database user is not the owner and

you do not specify the table owner name.

#ou can specify the table owner name in the target instance or in the session properties.

'hen you enter the table owner name in the session properties, you oerride the

transformation properties.

#ote$ 'hen you specify the table owner name and you set the s)lid for a D databasein the enironment &63, the %owerCenter &erer uses table owner name in the target


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instance. !o use the table owner name specified in the &*! s)lid statement, do not enter a

name in the target name prefi.

!o specify a target owner name at the target instance leel:

1. In the Designer, open the apping Designer tool.

. Double0click the title bar of a relational target instance in your mapping.

. 7n the %roperties tab, enter the table owner name or prefi in the (alue field for

!able +ame %refi.

E. Click 7>.

'dding "re/ and "ost/(ession (+L Co!!ands

#ou can enter pre0 and post0session &63 commands on the %roperties tab of the target

instance in a mapping. #ou might want to run pre0 and post0session &63 on the target todrop indees before a session runs, and recreate them when the session completes.

!he %owerCenter &erer runs pre0session &63 commands against the target database

before it reads the source. It runs post0session &63 commands against the target database

after it writes to the target.

#ou can oerride the &63 commands on the appings tab of the session properties. #ou

can also configure the %owerCenter &erer to stop or continue when it encounters errors

eecuting pre0 or post0session &63 commands. -se the following guidelines when you

enter pre0 and post0session &63 commands in the target instance:


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• #ou can use any command that is alid for the database type. Howeer, the

%owerCenter &erer does not allow nested comments, een though the database

might.• #ou cannot use session or mapping ariables in the target pre0 and post0session

&63 commands.

•

-se a semi0colon


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from relational or flat file sources.

7utput%assie"

Connected

Defines mapplet output rows. 2ailable in

the applet Designer.

9ank 2ctie"Connected 3imits records to a top or bottom range.

9outer 2ctie"

Connected

9outes data into multiple transformations

based on group conditions.

&e)uence Generator %assie"Connected

Generates primary keys.

&orter 2ctie"Connected &orts data based on a sort key.

&ource 6ualifier

2ctie"

Connected

9epresents the rows that the %owerCenter

&erer reads from a relational or flat filesource when it runs a session.

&tored %rocedure

%assie"

Connected or-nconnected

Calls a stored procedure.

!ransaction Control2ctie"

ConnectedDefines commit and rollback transactions.

-nion 2ctie"Connectederges data from different databases or flat

file systems.

-pdate &trategy2ctie"

Connected

Determines whether to insert, delete, update,

or reject rows.

?3 Generator 2ctie"Connected

9eads data from one or more input ports andoutputs ?3 through a single output port.

?3 %arser 2ctie"Connected

9eads ?3 from one input port and outputsdata to one or more output ports.

?3 &ource

6ualifier

2ctie"

Connected

9epresents the rows that the %owerCenter

&erer reads from an ?3 source when it

runs a session.

&ome transformations might include other tabs, such as the Condition tab, where you

enter conditions in a $oiner or +ormalier transformation.

'hen you configure transformations, you might perform the following tasks:


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• 'dd ports. Define the columns of data that moe into and out of the

transformation.

• 'dd groups. In some transformations, define input or output groups that define a

row of data entering or leaing the transformation.

• %nter e&pressions. *nter &630like epressions in some transformations that

transform the data.• Define local -ariables. Define local ariables in some transformations that

temporarily store data.

• O-erride default -alues. Configure default alues for ports to handle input nulls

and output transformation errors.

• %nter tracing le-els. Choose the amount of detail the %owerCenter &erer writes

in the session log about a transformation.

Transfor!ation %&pression Return 3alue

2ggregator

%erforms an aggregate calculation

based on all data passed through thetransformation. 2lternatiely, youcan specify a filter for records in the

aggregate calculation to eclude

certain kinds of records. For

eample, you can find the totalnumber and aerage salary of all

employees in a branch office using

this transformation.

!he result of an aggregate calculation

for a port.

*pression

%erforms a calculation based on

alues within a single row. Foreample, based on the price and

)uantity of a particular item, youcan calculate the total purchase

price for that line item in an order.

!he result of a row0leel calculationfor a port.

Filter

&pecifies a condition used to filter

rows passed through this

transformation. For eample, if youwant to write customer data to the

2D8D*! table for customers

with outstanding balances, youcould use the Filter transformation

to filter customer data.

!9-* or F23&*, depending on

whether a row meets the specifiedcondition. 7nly rows that return

!9-* are passed through this

transformation. !he transformation

applies this alue to each row passedthrough it.

9ank &ets the conditions for rows

included in a rank. For eample,

you can rank the top 1@ salespeoplewho are employed with the

!he result of a condition or

calculation for a port.


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company.

9outer

9outes data into multiple

transformations based on a group

epression. For eample, you can

use this transformation to comparethe salaries of employees at three

different pay leels. #ou can do this

by creating three groups in the9outer transformation. For eample,

create one group epression for

each salary range.

!9-* or F23&*, depending on

whether a row meets the specified

group epression. 7nly rows thatreturn !9-* pass through each user0

defined group in this transformation.

9ows that return F23&*automatically pass through the

default group.

-pdate &trategy

Flags a row for update, insert,delete, or reject. #ou use this

transformation when you want to

control updates to a target, based onsome condition you apply. For

eample, you might use the -pdate

&trategy transformation to flag all

customer rows for update when themailing address has changed, or flag

all employee rows for reject for

people who no longer work for thecompany.

!he numeric codes for update, insert,

delete, or reject. !he transformation

applies this alue to each row passed

through it.

!ransaction

Control

&pecifies a condition used to

determine the action the%owerCenter &erer performs,

either commit, roll back, or no

transaction change. #ou use this

transformation when you want tocontrol commit and rollback

transactions based on a row or set of

rows that pass through thetransformation. For eample, you

can use this transformation to

commit a set of rows based on anorder entry date.

7ne of the following built0in

ariables, depending on whether or

not a row meets the specifiedcondition:• !C8C7+!I+-*8!92+&2C!I

7+

• !C8C7I!8*F79*

• !C8C7I!82F!*9

• !C897332C>8*F79*

• !C897332C>82F!*9

!he %owerCenter &erer performs

actions based on the return alue.

Guidelines for Configuring 3ariable "orts

Consider the following factors when you configure ariable ports in a transformation:


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• "ort order. !he %owerCenter &erer ealuates ports by dependency. !he order of

the ports in a transformation must match the order of ealuation: input ports,

ariable ports, output ports.• Datatype. !he datatype you choose reflects the return alue of the epression you

enter.

•

3ariable initiali4ation. !he %owerCenter &erer sets initial alues in ariable ports. !his allows you to create counters.

"ort Order

!he %owerCenter &erer ealuates ports in the following order:

1. nput ports. !he %owerCenter &erer ealuates all input ports first since they do

not depend on any other ports. !herefore, you can create input ports in any order.&ince they do not reference other ports, the %owerCenter &erer does not order

input ports.

. 3ariable ports. (ariable ports can reference input ports and ariable ports, but

not output ports. ecause ariable ports can reference input ports, the%owerCenter &erer ealuates ariable ports after input ports. 3ikewise, since

ariable can reference other ariables, the display order for ariable ports is the

same as the order in which the %owerCenter &erer ealuates each ariable.

For eample, if you calculate the original alue of a building and then adjust fordepreciation, you might create the original alue calculation as a ariable port.

!his ariable port needs to appear before the port that adjusts for depreciation.

. Output ports. ecause output ports can reference input ports and ariable ports,the %owerCenter &erer ealuates output ports last. !he display order for output ports does not matter since output ports cannot reference other output ports. e

sure output ports display at the bottom of the list of ports.

Datatype

'hen you configure a port as a ariable, you can enter any epression or condition in it.!he datatype you choose for this port reflects the return alue of the epression you enter.

If you specify a condition through the ariable port, any numeric datatype returns the

alues for !9-*


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• @1"@1"1/ for Date"!ime ports with %&erer E.@ date handling compatibility

disabled

• @1"@1"@@@1 for Date"!ime ports with %&erer E.@ date handling compatibility

enabled

!herefore, you can use ariables as counters, which need an initial alue. For eample,you can create a numeric ariable with the following epression:

(291 N 1

!his epression counts the number of rows in the (291 port. If the initial alue of theariable were set to +-33, the epression would always ealuate to +-33. !his is why

the initial alue is set to ero.

• nput port. !he system default alue for null input ports is +-33. It displays as

a blank in the transformation. If an input alue is +-33, the %owerCenter &erer

leaes it as +-33.• Output port. !he system default alue for output transformation errors is

*9979. !he default alue displays in the transformation as

*9979


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transformation errors. It skips rows

with errors and writes the input data

and error message in the session logfile.

%ntering User/Defined Default 3alues

#ou can oerride the system default alues with user0defined default alues for supported

input, input"output, and output ports within a connected transformation.

• nput ports. #ou can enter user0defined default alues for input ports if you do

not want the %owerCenter &erer to treat null alues as +-33.

• Output ports. #ou can enter user0defined default alues for output ports if you do

not want the %owerCenter &erer to skip the row, or if you want the %owerCenter

&erer to write a specific message with the skipped row to the session log.•

nput*output ports. #ou can enter user0defined default alues to handle nullinput alues for input"output ports in the same way you can enter user0defined

default alues for null input alues for input ports. #ou cannot enter user0defineddefault alues for output transformation errors in an input"output port.

#ote$ !he %owerCenter &erer ignores user0defined default alues for unconnected

transformations. For eample, if you call a 3ookup or &tored %rocedure transformation

through an epression, the %owerCenter &erer ignores any user0defined default alueand uses the system default alue only.

!able A0A shows the ports for each transformation that support user0defined default

alues:

!able A0A. !ransformations &upporting -ser0Defined Default (alues

Transfor!ation

nput 3alues for

nput "ort

nput*Output

"ort

Output 3alues for

Output "ort

Output 3alues

for

nput*Output

"ort

2ggregator &upported +ot &upported +ot &upported

Custom &upported &upported +ot &upported

*pression &upported &upported +ot &upported

*ternal %rocedure &upported &upported +ot &upported

Filter &upported +ot &upported +ot &upported

$oiner &upported &upported +ot &upported


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3ookup &upported &upported +ot &upported

+ormalier &upported &upported +ot &upported

9ank +ot &upported &upported +ot &upported

9outer &upported +ot &upported +ot &upported

&tored %rocedure &upported &upported +ot &upported

&e)uence Generator n"a +ot &upported +ot &upported

&orter &upported +ot &upported +ot &upported

&ource 6ualifier +ot &upported n"a +ot &upported

!ransaction Control +ot &upported n"a +ot &upported

-nion &upported &upported n"a

-pdate &trategy &upported n"a +ot &upported

?3 Generator n"a &upported +ot &upported

?3 %arser &upported n"a +ot &upported

?3 &ource

6ualifier +ot &upported n"a +ot &upported

#ou hae the following options to enter user0defined default alues:

• Constant -alue. #ou can use any constant


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+-33

K-nknown (alueK

K+ull input dataK

%ntering Constant %&pressions

2 constant epression is any epression that uses transformation functions


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#ou can enter a user0defined default input alue if you do not want the %owerCenter

&erer to treat null alues as +-33. #ou can perform the following functions to oerride

null alues:

• 9eplace the null alue with a constant alue or constant epression.

•

&kip the null alue with an *9979 function.• 2bort the session with the 279! function.

!able A0 summaries how the %owerCenter &erer handles null input for input andinput"output ports:

!able A0. Default (alues for Input and Input"7utput %orts

Default

3alue

Default

3alue

Type

Description

+-33

+7'+ D*%!K, you could set the default alue toK-+>+7'+ D*%!K. Depending on the transformation, the %owerCenter &erer passes

K-+>+7'+ D*%!K to an epression or ariable within the transformation or to the net

transformation in the data flow.


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!he %owerCenter &erer replaces all null alues in the *2I3 port with the string

K-+>+7'+ D*%!.K

D*%!8+2* 9*%32C*D (23-*

Housewares Housewares

+-33 -+>+7'+ D*%!

%roduce %roduce

(kipping #ull Records

-se the *9979 function as the default alue when you do not want null alues to pass

into a transformation. For eample, you might want to skip a row when the input alue of D*%!8+2* is +-33. #ou could use the following epression as the default alue:

*9979


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D*%!8ID


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Constant or

Constant

*pression

-ser0

Defined

!he %owerCenter &erer replaces the error with the

default alue.

!he %owerCenter &erer does not increase the errorcount or write a message to the session log.

279!-ser0

Defined

!he session aborts and the %owerCenter &erer writes amessage to the session log.

!he %owerCenter &erer does not increase the error

count or write rows to the reject file.

Replacing %rrors

If you do not want the %owerCenter &erer to skip a row when a transformation error

occurs, you can use a constant or constant epression as the default alue for an output port. For eample, if you hae a numeric output port called +*!8&2329# and you want

to use the constant alue KJJJJK when a transformation error occurs, assign the default

alue JJJJ to the +*!8&2329# port. If there is any transformation error


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IIF

!he following eamples show how user0defined default alues may oerride the *9979

function in the epression:

•

Constant -alue or e&pression. !he constant alue or epression oerrides the*9979 function in the output port epression.

For eample, if you enter K@K as the default alue, the %owerCenter &erer

oerrides the *9979 function in the output port epression. It passes the alue @

when it encounters an error. It does not skip the row or write K+egatie &aleK in thesession log.

• '5ORT. !he 279! function oerrides the *9979 function in the output port

epression.

If you use the 279! function as the default alue, the %owerCenter &ereraborts the session when a transformation error occurs. !he 279! functionoerrides the *9979 function in the output port epression.

• %RROR. If you use the *9979 function as the default alue, the %owerCenter

&erer includes the following information in the session log:

o *rror message from the default alue

o *rror message indicated in the *9979 function in the output port

epression

o &kipped row

For eample, you can oerride the default alue with the following*9979 function:

*9979


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!*811@1J %ort S7-!8&23*&T: Default alue is:

*9979


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!able A0J describes the session log tracing leels:

!able A0J. &ession 3og !racing 3eels

Tracing

Le-el

Description

+ormal

%owerCenter &erer logs initialiation and status informationQ errors

encountered, and skipped rows due to transformation row errors. &ummariessession results, but not at the leel of indiidual rows.

!erse%owerCenter &erer logs initialiation information as well as error messages

and notification of rejected data.

(erbose

Init

In addition to normal tracing, %owerCenter &erer logs additional

initialiation details, names of inde and data files used, and detailed

transformation statistics.

(erboseData

In addition to erbose initialiation tracing, %owerCenter &erer logs eachrow that passes into the mapping. 2lso notes where the %owerCenter &erer

truncates string data to fit the precision of a column and proides detailed

transformation statistics.2llows the %owerCenter &erer to write errors to both the session log and

error log when you enable row error logging.

'hen you configure the tracing leel to erbose data, the %owerCenter&erer writes row data for all rows in a block when it processes a

transformation.

y default, the tracing leel for eery transformation is +ormal. #ou change the tracingleel to a (erbose setting only when you need to debug a transformation that is not

behaing as epected. !o add a slight performance boost, you can also set the tracingleel to !erse, writing the minimum of detail to the session log when running a workflow

containing the transformation.

'hen you configure a session, you can oerride the tracing leels for indiidual

transformations with a single tracing leel for all transformations in the session.

appings can contain reusable and non0reusable transformations. +on0reusabletransformations eist within a single mapping. 9eusable transformations can be used in

multiple mappings.

For eample, you might create an *pression transformation that calculates alue0added

ta for sales in Canada, which is useful when you analye the cost of doing business inthat country. 9ather than perform the same work eery time, you can create a reusable

transformation. 'hen you need to incorporate this transformation into a mapping, you

add an instance of it to the mapping. 3ater, if you change the definition of thetransformation, all instances of it inherit the changes.


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!he Designer stores each reusable transformation as metadata separate from any mapping

that uses the transformation. If you reiew the contents of a folder in the +aigator, you

see the list of all reusable transformations in that folder.

*ach reusable transformation falls within a category of transformations aailable in the

Designer. For eample, you can create a reusable 2ggregator transformation to performthe same aggregate calculations in multiple mappings, or a reusable &tored %rocedure

transformation to call the same stored procedure in multiple mappings.

#ou can create most transformations as a non0reusable or reusable. Howeer, you can

only create the *ternal %rocedure transformation as a reusable transformation.

'hen you add instances of a reusable transformation to mappings, you must be careful

that changes you make to the transformation do not inalidate the mapping or generateunepected data.

nstances and nherited Changes

'hen you add a reusable transformation to a mapping, you add an instance of thetransformation. !he definition of the transformation still eists outside the mapping,

while a copy


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reusable transformation. !he transformation designed in the mapping then

becomes an instance of a reusable transformation maintained elsewhere in the

repository.

If you promote a transformation to reusable status, you cannot demote it. Howeer, you

can create a non0reusable instance of it.

#ote$ &e)uence Generator transformations must be reusable in mapplets. #ou cannot

demote reusable &e)uence Generator transformations to non0reusable in a mapplet.

!o create a reusable transformation:

1. In the Designer, switch to the !ransformation Deeloper.

. Click the button on the !ransformation toolbar corresponding to the type of

transformation you want to create.

. Click and drag within the workbook to create the transformation.

E. Double0click the transformation title bar to open the dialog displaying its properties.

/. Click the 9ename button and enter a descriptie name for the transformation, and

click 7>.

!he naming conention for reusable transformations is reuTransformation_Name.

A. Click the %orts tab, then add any input and output ports you need for thistransformation.

. &et the other properties of the transformation, and click 7>.

!hese properties ary according to the transformation you create. For eample, if

you create an *pression transformation, you need to enter an epression for one

or more of the transformation output ports. If you create a &tored %roceduretransformation, you need to identify the stored procedure to call.

. Choose 9epository0&ae.

"ro!oting #on/Reusable Transfor!ations

!he other techni)ue for creating a reusable transformation is to promote an eisting

transformation within a mapping. y checking the ake 9eusable option in the *dit

!ransformations dialog bo, you instruct the Designer to promote the transformation andcreate an instance of it in the mapping.


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!o promote a non0reusable transformation:

1. In the Designer, open a mapping and double0click the title bar of the

transformation you want to promote.

. &elect the ake 9eusable option.

. 'hen prompted whether you are sure you want to promote the transformation,

click #es.

E. Click 7> to return to the mapping.

/. Choose 9epository0&ae.

+ow, when you look at the list of reusable transformations in the folder you are workingin, the newly promoted transformation appears in this list.

Creating #on/Reusable nstances of Reusable Transfor!ations

#ou can create a non0reusable instance of a reusable transformation within a mapping.9eusable transformations must be made non0reusable within the same folder. If you want

to hae a non0reusable instance of a reusable transformation in a different folder, you

need to first make a non0reusable instance of the transformation in the source folder, and

then copy it into the target folder.

!o create a non0reusable instance of a reusable transformation:

1. In the Designer, open a mapping.

. In the +aigator, select an eisting transformation and drag the transformation

into the mapping workspace. Hold down the Ctrl key before you release thetransformation.

!he status bar displays the following message:

4ake a non0reusable copy of this transformation and add it to this mapping.5

. 9elease the transformation.

!he Designer creates a non0reusable instance of the eisting reusable

transformation.

E. Choose 9epository0&ae.

'dding Reusable Transfor!ations to Mappings


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2fter you create a reusable transformation, you can add it to mappings.

!o add a reusable transformation:

1. In the Designer, switch to the apping Designer.

. 7pen or create a mapping.

. In the list of repository objects, drill down until you find the reusabletransformation you want in the !ransformations section of a folder.

E. Click and drag the transformation from the +aigator into the mapping.

2 copy


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Re-erting to Original Reusable Transfor!ation

If you change the properties of a reusable transformation in a mapping, you can reert to

the original reusable transformation properties by clicking the 9eert button.

informatica tips 1

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