tag:blogger.com,1999:blog-34842593137225013352024-03-27T00:22:20.803-07:00INFORMATICA INTERVIEW QUESTIONSADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.comBlogger67125tag:blogger.com,1999:blog-3484259313722501335.post-21269469985556869492014-12-12T02:31:00.003-08:002014-12-12T02:32:28.602-08:00 What are the changes we observe when we promote a non resuable Sequence Generator to a resuable one? And what happens if we set the Number of Cached Values to 0 for a reusable transformation? <div dir="ltr" style="text-align: left;" trbidi="on">
<b>Ans.</b> When we convert a non reusable sequence generator to resuable one we observe that the <b>Number of Cached Values</b> is set to 1000 by default; And the <b>Reset</b> property is disabled.
<br />
When we try to set the <b>Number of Cached Values</b> property of a Reusable Sequence Generator to 0 in the Transformation Developer we encounter the following error message:
<br />
<b>The number of cached values must be greater than zero for reusable sequence transformation.</b>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com1tag:blogger.com,1999:blog-3484259313722501335.post-71059117089629061892014-12-12T02:31:00.001-08:002014-12-12T02:32:28.620-08:00Suppose we have 100 records coming from the source. Now for a target column population we used a Sequence generator. Suppose the Current Value is 0 and End Value of Sequence generator is set to 80. What will happen? <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<b>Ans.</b> <b>End Value</b> is the maximum value the Sequence Generator
will generate. After it reaches the End value the session fails with
the following error message:
<br />
TT_11009 Sequence Generator Transformation: Overflow error.
<br />
Failing of session can be handled if the Sequence Generator is configured to <b>Cycle</b>
through the sequence, i.e. whenever the Integration Service reaches the
configured end value for the sequence, it wraps around and starts the
cycle again, beginning with the configured Start Value.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-52346027036632526862014-12-12T02:30:00.000-08:002014-12-12T02:32:28.612-08:00Suppose we have a source table populating two target tables. We connect the NEXTVAL port of the Sequence Generator to the surrogate keys of both the target tables. Will the Surrogate keys in both the target tables be same? If not how can we flow the same sequence values in both of them. <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<b>Ans.</b>
When we connect the <b>NEXTVAL</b> output port of the <b>Sequence Generator</b> directly to the surrogate key columns of the target tables, the <b>Sequence number will not be the same</b>.
<br />
A block of sequence numbers is sent to one target tables surrogate key
column. The second targets receives a block of sequence numbers from the
Sequence Generator transformation only after the first target table
receives the block of sequence numbers.
<br />
Suppose we have 5 rows coming from the source, so the targets will have
the sequence values as TGT1 (1,2,3,4,5) and TGT2 (6,7,8,9,10). [Taken
into consideration Start Value 0, Current value 1 and Increment by 1.
<br />
Now suppose the requirement is like that we need to have the same surrogate keys in both the targets.
<br />
Then the easiest way to handle the situation is to put an <b>Expression Transformation</b>
in between the Sequence Generator and the Target tables. The SeqGen
will pass unique values to the expression transformation, and then the
rows are routed from the expression transformation to the targets.
<br />
<div align="center">
<img alt="Sequence Generator" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview20.png" title="Sequence Generator" />
</div>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-23704035521281608212014-12-12T02:29:00.001-08:002014-12-12T02:32:28.609-08:00Define the Properties available in Sequence Generator transformation in brief. <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<b>Ans.</b>
<br />
<table align="center" border="1" cellpadding="10" cellspacing="0" style="width: 70%px;">
<tbody>
<tr bgcolor="#C2DFFF"><td>Sequence Generator Properties</td><td>Description </td></tr>
<tr bgcolor="#C2DFFF"><td> Start Value </td><td> Start value of the
generated sequence that we want the Integration Service to use if we use
the Cycle option. If we select Cycle, the Integration Service cycles
back to this value when it reaches the end value. Default is 0. </td></tr>
<tr bgcolor="#C2DFFF"><td> Increment By </td><td> Difference between two consecutive values from the NEXTVAL port.Default is 1. </td></tr>
<tr bgcolor="#C2DFFF"><td> End Value </td><td> Maximum value generated
by SeqGen. After reaching this value the session will fail if the
sequence generator is not configured to cycle.Default is 2147483647. </td></tr>
<tr bgcolor="#C2DFFF"><td> Current Value </td><td> Current value of the
sequence. Enter the value we want the Integration Service to use as the
first value in the sequence. Default is 1. </td></tr>
<tr bgcolor="#C2DFFF"><td> Cycle </td><td> If selected, when the
Integration Service reaches the configured end value for the sequence,
it wraps around and starts the cycle again, beginning with the
configured Start Value. </td></tr>
<tr bgcolor="#C2DFFF"><td> Number of Cached Values </td><td> Number of
sequential values the Integration Service caches at a time. Default
value for a standard Sequence Generator is 0. Default value for a
reusable Sequence Generator is 1,000. </td></tr>
<tr bgcolor="#C2DFFF"><td> Reset </td><td> Restarts the sequence at the
current value each time a session runs.This option is disabled for
reusable Sequence Generator transformations. </td></tr>
</tbody></table>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-58125267320333713622014-12-12T02:28:00.001-08:002014-12-12T02:32:28.616-08:00 What is a Sequence Generator Transformation? <div dir="ltr" style="text-align: left;" trbidi="on">
<h3>
</h3>
<br />
<b>Ans.</b> A <b>Sequence Generator</b> transformation is a <b>Passive</b> and <b>Connected</b> transformation that generates numeric values.
It is used to create unique primary key values, replace missing primary keys, or cycle through a sequential range of numbers.
This transformation by <b>default</b> contains <b>ONLY Two OUTPUT</b> ports namely <b>CURRVAL</b> and <b>NEXTVAL</b>. We cannot edit or delete these ports neither we cannot add ports to this unique transformation.
We can create approximately two billion unique numeric values with the widest range from 1 to 2147483647.
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com2tag:blogger.com,1999:blog-3484259313722501335.post-33248725214733922302014-12-12T02:25:00.002-08:002014-12-12T02:26:10.573-08:00Suppose we have the EMP table as our source. In the target we want to view those employees whose salary is greater than or equal to the average salary for their departments. Describe your mapping approach. <div dir="ltr" style="text-align: left;" trbidi="on">
Our Mapping will look like this:
<br />
<div align="center">
ahref="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview10.png"
<img alt="Mapping using Joiner" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview10-s.png" title="Mapping using Joiner" />
</div>
To start with the mapping we need the following transformations:
<br />
After the Source qualifier of the EMP table place a <b>Sorter Transformation</b> . Sort based on <b>DEPTNO</b>port.
<br />
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview11.png">
<img alt="Sorter Ports Tab" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview11-s.png" title="Sorter Ports Tab" />
</a>
</div>
Next we place a <b>Sorted Aggregator Transformation</b>. Here we will find out the <b>AVERAGE SALARY</b> for each (GROUP BY) <b>DEPTNO</b>.
<br />
When we perform this aggregation, we lose the data for individual employees.
<br />
To maintain employee data, we must pass a branch of the pipeline to the
Aggregator Transformation and pass a branch with the same sorted source
data to the Joiner transformation to maintain the original data.
<br />
When we join both branches of the pipeline, we join the aggregated data with the original data.
<br />
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview12.png">
<img alt="Aggregator Ports Tab" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview12-s.png" title="Aggregator Ports Tab" />
</a>
</div>
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview13.png">
<img alt="Aggregator Properties Tab" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview13-s.png" title="Aggregator Properties Tab" />
</a>
</div>
So next we need <b>Sorted Joiner Transformation</b> to join the sorted aggregated data with the original data, based on <b>DEPTNO</b>.
Here we will be taking the aggregated pipeline as the Master and original dataflow as Detail Pipeline.
<br />
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview14.png">
<img alt="Joiner Condition Tab" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview14-s.png" title="Joiner Condition Tab" />
</a>
</div>
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview15.png">
<img alt="Joiner Properties Tab" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview15-s.png" title="Joiner Properties Tab" />
</a>
</div>
After that we need a <b>Filter Transformation</b> to filter out the employees having salary less than average salary for their department.
<br />
Filter Condition: <b>SAL>=AVG_SAL</b>
<br />
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview16.png">
<img alt="Filter Properties Tab" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview16-s.png" title="Filter Properties Tab" />
</a>
</div>
Lastly we have the Target table instance.
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-65388347610106331312014-12-12T02:24:00.001-08:002014-12-12T02:26:10.589-08:00What are the transformations that cannot be placed between the sort origin and the Joiner transformation so that we do not lose the input sort order. <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<b>Ans.</b> The best option is to place the Joiner transformation directly after the sort origin to maintain sorted data.
However do not place any of the following transformations between the sort origin and the Joiner transformation:
<br />
<div class="xtypo_list">
<ul>
<li>Custom
</li>
<li><b>Unsorted</b>Aggregator
</li>
<li>Normalizer
</li>
<li>Rank
</li>
<li>Union transformation
</li>
<li>XML Parser transformation
</li>
<li>XML Generator transformation
</li>
<li>Mapplet [if it contains any one of the above mentioned transformations]
</li>
</ul>
</div>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-87910324020746253912014-12-12T02:23:00.001-08:002014-12-12T02:26:10.592-08:00 Suppose we configure Sorter transformations in the master and detail pipelines with the following sorted ports in order: ITEM_NO, ITEM_NAME, PRICE. When we configure the join condition, what are the guidelines we need to follow to maintain the sort order? <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<b>Ans.</b> If we have sorted both the master and detail pipelines in
order of the ports say ITEM_NO, ITEM_NAME and PRICE we must ensure that:
<br />
<div class="xtypo_list">
<ul>
<li>Use ITEM_NO in the First Join Condition.
</li>
<li>If we add a Second Join Condition, we must use ITEM_NAME.
</li>
<li>If we want to use PRICE as a Join Condition apart from ITEM_NO, we must also use ITEM_NAME in the Second Join Condition.
</li>
<li>If we skip ITEM_NAME and join on ITEM_NO and PRICE, we will <b>lose the input sort order</b> and the Integration Service <b>fails the session</b>.
</li>
</ul>
</div>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-19003880601398229452014-12-12T02:22:00.000-08:002014-12-12T02:26:10.565-08:00How does Joiner transformation treat NULL value matching. <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<b>Ans.</b> The Joiner transformation <b>does not match null values</b>.
<br />
For example, if both EMP_ID1 and EMP_ID2 contain a row with a null
value, the Integration Service does not consider them a match and does
not join the two rows.
<br />
To join rows with null values, replace null input with <b>default values</b> in the Ports tab of the joiner, and then join on the default values.
<br />
<b>Note:</b>
If a result set includes fields that do not contain data in either of
the sources, the Joiner transformation populates the empty fields with
null values.
If we know that a field will return a NULL and we do not want to insert
NULLs in the target, set a default value on the Ports tab for the
corresponding port.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-18147733347278738952014-12-12T02:21:00.001-08:002014-12-12T02:26:10.560-08:00 Describe the impact of number of join conditions and join order in a Joiner Transformation. <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
We can define <b>one or more conditions</b> based on <b>equality</b> between the specified master and detail sources.
Both ports in a condition must have the <b>same datatype</b>.
If we need to use two ports in the join condition with non-matching datatypes we must convert the datatypes so that they match.
The Designer validates datatypes in a join condition.
<br />
<b>Additional ports</b> in the join condition <b>increases the time</b> necessary to join two sources.
<br />
The order of the ports in the join condition can impact the performance of the Joiner transformation.
If we use multiple ports in the join condition, the Integration Service compares the ports in the order we specified.
<br />
<b>NOTE:</b> Only equality operator is available in joiner join condition.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-88857144688709589062014-12-12T02:20:00.005-08:002014-12-12T02:26:10.596-08:00Define the various Join Types of Joiner Transformation. <div dir="ltr" style="text-align: left;" trbidi="on">
<ul>
<li>In a <b>normal join</b> , the Integration Service discards all rows
of data from the master and detail source that do not match, based on
the join condition.
</li>
<li>A <b>master outer join</b> keeps all rows of data from the
detail source and the matching rows from the master source. It discards
the unmatched rows from the master source.
</li>
<li>A <b>detail outer</b> join keeps all rows of data from the
master source and the matching rows from the detail source. It discards
the unmatched rows from the detail source.
</li>
<li>A <b>full outer</b> join keeps all rows of data from both the master and detail sources.
</li>
</ul>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-48062800727677072342014-12-12T02:19:00.004-08:002014-12-12T02:26:10.585-08:00What are the different types of Joins available in Joiner Transformation? <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
In SQL, a join is a relational operator that combines data
from multiple tables into a single result set. The Joiner transformation
is similar to an SQL join except that data can originate from different
types of sources
The Joiner transformation supports the following <b>types of joins</b> :
<br />
<div class="xtypo_list">
<ul>
<li><b>Normal</b>
</li>
<li><b>Master Outer</b>
</li>
<li><b>Detail Outer</b>
</li>
<li><b>Full Outer</b>
</li>
</ul>
</div>
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview9.png">
<img alt="Join Type property of Joiner Transformation class="caption"" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview9-s.png" title="Join Type property of Joiner Transformation " />
</a>
</div>
<b>Note:</b> A <b>normal or master outer</b> join <b>performs faster</b> than a full outer or detail outer join.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-34943355249933748722014-12-12T02:18:00.005-08:002014-12-12T02:26:10.576-08:00Out of the two input pipelines of a joiner, which one will you set as the master pipeline? <div dir="ltr" style="text-align: left;" trbidi="on">
During a session run, the Integration Service compares <b>each row of the master source</b> against the detail source.
The master and detail sources need to be configured for <b>optimal performance</b>.
To improve performance for an <b>Unsorted Joiner</b> transformation, use the source with <b>fewer rows</b>
as the master source. The fewer unique rows in the master, the fewer
iterations of the join comparison occur, which speeds the join process.
<br />
When the Integration Service processes an unsorted Joiner
transformation, it reads all master rows before it reads the detail
rows.
The Integration Service blocks the detail source while it <b>caches rows from the master source</b>.
Once the Integration Service reads and caches all master rows, it unblocks the detail source and reads the detail rows.
<br />
To improve performance for a <b>Sorted Joiner</b> transformation, use the source with <b>fewer duplicate key values</b> as the master source.
<br />
When the Integration Service processes a sorted Joiner transformation, it blocks data based on the mapping configuration and
it stores <b>fewer rows</b> in the cache, increasing performance.
<br />
Blocking logic is possible if master and detail input to the Joiner transformation originate from <b>different sources</b>.
Otherwise, it does not use blocking logic. Instead, it stores<b> more rows</b> in the cache.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-40688175309864408262014-12-12T02:18:00.001-08:002014-12-12T02:26:10.581-08:00State the limitations where we cannot use Joiner in the mapping pipeline. <div dir="ltr" style="text-align: left;" trbidi="on">
<br />
The Joiner transformation accepts input from most transformations. However, following are the limitations:
<br />
<div class="xtypo_list">
<ul>
<li>Joiner transformation cannot be used when either of the input pipeline contains an <b>Update Strategy</b> transformation.
</li>
<li>Joiner transformation cannot be used if we connect a <b>Sequence Generator</b> transformation directly before the Joiner transformation.
</li>
</ul>
</div>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-3120443633700290582014-12-12T02:17:00.000-08:002014-12-12T02:26:10.569-08:00What is a Joiner Transformation and why it is an Active one? <div dir="ltr" style="text-align: left;" trbidi="on">
A <b>Joiner</b> is an <b>Active</b> and <b>Connected</b>
transformation used to join source data from the same source system or
from two related heterogeneous sources residing in different locations
or file systems.
<br />
The Joiner transformation joins sources with at least one matching
column. The Joiner transformation uses a condition that matches one or
more pairs of columns between the two sources.
<br />
The two input pipelines include a master pipeline and a detail pipeline
or a master and a detail branch. The master pipeline ends at the Joiner
transformation, while the detail pipeline continues to the target.
<br />
In the Joiner transformation, we must configure the transformation
properties namely Join Condition, Join Type and Sorted Input option to
improve Integration Service performance.
<br />
The join condition contains ports from both input sources that must
match for the Integration Service to join two rows. Depending on the
type of join selected, the Integration Service either <b>adds the row to the result set or discards the row</b>.
<br />
The Joiner transformation produces result sets based on the join type,
condition, and input data sources. Hence it is an Active transformation.
<br />
<br /></div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-32021245093816479482014-12-12T01:35:00.007-08:002014-12-12T01:36:38.296-08:00Suppose we have two Source Qualifier transformations SQ1 and SQ2 connected to Target tables TGT1 and TGT2 respectively. How do you ensure TGT2 is loaded after TGT1? <div dir="ltr" style="text-align: left;" trbidi="on">
<h5>
</h5>
<b>Ans.</b> If we have multiple Source Qualifier transformations
connected to multiple targets, we can designate the order in which the
Integration Service loads data into the targets.
<br />
In the Mapping Designer, We need to configure the <b>Target Load Plan</b> based on the Source Qualifier transformations in a mapping to specify the required loading order.
<br />
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview6.png">
<img alt="Target Load Plan" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview6-s.png" title="Target Load Plan" />
</a>
</div>
<div align="center">
<img alt="Target Load Plan Ordering" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview7.png" title="Target Load Plan Ordering" />
</div>
<h5>
Suppose we have a Source Qualifier transformation that populates
two target tables. How do you ensure TGT2 is loaded after TGT1?
</h5>
<b>Ans.</b> In the Workflow Manager, we can Configure <b>Constraint based load ordering</b>
for a session. The Integration Service orders the target load on a
row-by-row basis. For every row generated by an active source, the
Integration Service loads the corresponding transformed row first to the
primary key table, then to the foreign key table.
<br />
Hence if we have one Source Qualifier transformation that provides data
for multiple target tables having primary and foreign key relationships,
we will go for Constraint based load ordering.
<br />
<div align="center">
<a href="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview8.png">
<img alt="Constraint based loading" class="caption" src="http://png.dwbiconcepts.com/images/tutorial/info_interview/info_interview8-s.png" title="Constraint based loading" />
</a>
</div>
<h3>
</h3>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-41026576649787832352014-12-12T01:35:00.005-08:002014-12-12T01:36:59.434-08:00What is the maximum number we can use in Number Of Sorted Ports for Sybase source system. <div dir="ltr" style="text-align: left;" trbidi="on">
<h5>
</h5>
<b>Ans.</b> Sybase supports a maximum of <b>16</b> columns in an ORDER BY clause. So if the source is Sybase, do not sort more than 16 columns.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-83842366087577803522014-12-12T01:35:00.003-08:002014-12-12T01:36:59.449-08:00Describe the scenarios where we go for Joiner transformation instead of Source Qualifier transformation. <div dir="ltr" style="text-align: left;" trbidi="on">
<h5>
</h5>
<b>Ans.</b> While joining Source Data of <b>heterogeneous sources</b> as well as to join <b>flat files</b> we will use the Joiner transformation.
Use the Joiner transformation when we need to join the following types of sources:
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<div class="xtypo_list">
<ul>
<li>Join data from different Relational Databases.
</li>
<li>Join data from different Flat Files.
</li>
<li>Join relational sources and flat files.
</li>
</ul>
</div>
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-87061417942142789722014-12-12T01:34:00.010-08:002014-12-12T01:36:59.454-08:00What happens if in the Source Filter property of SQ transformation we include keyword WHERE say, WHERE CUSTOMERS.CUSTOMER_ID > 1000. <div dir="ltr" style="text-align: left;" trbidi="on">
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</h5>
<b>Ans.</b> We use source filter to reduce the number of source records. If we include the string <b>WHERE</b> in the source filter, the Integration Service <b>fails the session</b>.
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</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-32755081087074443532014-12-12T01:34:00.006-08:002014-12-12T01:36:59.431-08:00What will happen if the SELECT list COLUMNS in the Custom override SQL Query and the OUTPUT PORTS order in SQ transformation do not match? <div dir="ltr" style="text-align: left;" trbidi="on">
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</h5>
<b>Ans.</b> Mismatch or Changing the order of the list of selected
columns to that of the connected transformation output ports may result
is <b>session failure.</b>
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</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-5587503764608872192014-12-12T01:34:00.003-08:002014-12-12T01:36:59.437-08:00Describe the situations where we will use the Source Filter, Select Distinct and Number Of Sorted Ports properties of Source Qualifier transformation. <div dir="ltr" style="text-align: left;" trbidi="on">
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<b>Ans.</b> <b>Source Filter</b> option is used basically to reduce the number of rows the Integration Service queries so as to improve performance.
<br />
<b>Select Distinct</b> option is used when we want the Integration
Service to select unique values from a source, filtering out unnecessary
data earlier in the data flow, which might improve performance.
<br />
<b>Number Of Sorted Ports</b> option is used when we want the source
data to be in a sorted fashion so as to use the same in some following
transformations like Aggregator or Joiner, those when configured for
sorted input will improve the performance.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-67387567248931018552014-12-12T01:33:00.007-08:002014-12-12T01:36:59.441-08:00Suppose we have used the Select Distinct and the Number Of Sorted Ports property in the SQ and then we add Custom SQL Query. Explain what will happen. <div dir="ltr" style="text-align: left;" trbidi="on">
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</h5>
<b>Ans.</b> Whenever we add Custom SQL or SQL override query it <b>overrides</b>
the User-Defined Join, Source Filter, Number of Sorted Ports, and
Select Distinct settings in the Source Qualifier transformation. Hence
only the user defined SQL Query will be fired in the database and all
the <b>other options will be ignored</b> .
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-81678547900997121772014-12-12T01:33:00.003-08:002014-12-12T01:36:59.445-08:00What happens to a mapping if we alter the datatypes between Source and its corresponding Source Qualifier? <div dir="ltr" style="text-align: left;" trbidi="on">
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</h5>
<b>Ans.</b> The Source Qualifier transformation displays the
transformation datatypes. The transformation datatypes determine how the
source database binds data when the Integration Service reads it.
<br />
Now if we alter the datatypes in the Source Qualifier transformation or the <b>datatypes in the source definition and Source Qualifier transformation do not match,</b> the Designer marks the <b>mapping as invalid</b> when we save it.
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</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-210425466597877152014-12-12T01:32:00.004-08:002014-12-12T01:36:59.427-08:00What is a Source Qualifier? What are the tasks we can perform using a SQ and why it is an ACTIVE transformation? <div dir="ltr" style="text-align: left;" trbidi="on">
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</h5>
<b>Ans.</b> A <b>Source Qualifier</b> is an Active and Connected Informatica transformation that reads the rows from a relational database or flat file source.
<br />
<div class="xtypo_list">
<ul>
<li>We can configure the <b>SQ</b> to <b>join</b> [Both <b>INNER</b> as well as <b>OUTER JOIN</b>] data originating from the same source database.
</li>
<li>We can use a source <b>filter</b> to reduce the number of rows the Integration Service queries.
</li>
<li>We can specify a number for <b>sorted ports</b> and the Integration Service adds an ORDER BY clause to the default SQL query.
</li>
<li>We can choose <b>Select Distinct</b>option for relational databases and the Integration Service adds a SELECT DISTINCT clause to the default SQL query.
</li>
<li>Also we can write <b>Custom/Used Defined SQL</b> query which will override the default query in the SQ by changing the default settings of the transformation properties.
</li>
<li>Also we have the option to write <b>Pre</b> as well as <b>Post SQL</b> statements to be executed before and after the SQ query in the source database.
</li>
</ul>
</div>
Since the transformation provides us with the property <b>Select Distinct</b>,
when the Integration Service adds a SELECT DISTINCT clause to the
default SQL query, which in turn affects the number of rows returned by
the Database to the Integration Service and hence it is an Active
transformation.
<br />
</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0tag:blogger.com,1999:blog-3484259313722501335.post-30157127625813094892014-12-11T23:08:00.000-08:002014-12-12T01:40:00.496-08:00How is the union transformation active transformattion<div dir="ltr" style="text-align: left;" trbidi="on">
Active Transformation: the transformation that change the no. of rows in the Target.<br /> Source (100 rows) ---> Active Transformation ---> Target (< or > 100 rows)Passive Transformation: the transformation that does not change the <br /> no. of rows in the Target.<br /> Source (100 rows) ---> Passive Transformation ---> Target (100 rows)<br /> Union Transformation: in Union Transformation we may combine the data from two (or) more sources. Assume Table-1 contains '10' rows and Table-2 contains '20' rows. If we combine the rows of Table-1 and Table-2 we will get a total of '30' rows in the Target. So it is definetly an Active Transformation.</div>
ADK TECHNOLOGIEShttp://www.blogger.com/profile/08119202262934429942noreply@blogger.com0