Put Item

Operation Name

Function overview

Data Model

Properties

Basic settings

Required settings

Property Action

Put option

Property Action

Data processing method

Comment

Schema

Input Schema

<?xml version="1.0" ?>
<table>
  <row>
    <column>Item name</column>
    <column><expected name>_expected</column> It will occur when [Report error if expected value is unmatched or does not exist]  is checked. The <expected name> becomes what is assigned to the [Expected name].
    <column>Attribute name</column>
    :
  </row>
  <row>
    :
  </row>
</table>

Output Schema

<?xml version="1.0" ?>
<table>
  <row>
    <column>Input schema of the failed item</column>
    :
    <column>error_message</column>
    <column>error_code</column>
    <column>status_code</column>
  </row>
  <row>
    :
  </row>
</table>

Loading schema in Mapper

Mass data processing

Transaction

PSP Usage

Available component variables

About write operation for which expected values are specified

• The following depicts what happens when [Report error if expected value is unmatched or does not exist] is checked and both scripts run concurrently.

  Sequence	Operation in script A	Operation in script B	The column value representing a version that is stored in the Amazon SimpleDB before the operation is performed.
  1	The version number retrieved from Amazon SimpleDB is '0'	The version number retrieved from Amazon SimpleDB is '0'	0
  2	Incrementing the value by 1 yields '1'	Incrementing the value by 1 yields '1'	0
  3	Expected value is '0'. The column value is updated with the incremented version '1' ->succeeds		0
  4		Expected value is '0'. The column value is updated with the incremented version '1' ->An error is raised	1

  
  In the scenario above, the check reveals the conflicting modifications because the script B detects that the value expected, which is '0' in this scenario, has been incremented by '1' in other transactions(in this case it is the transaction started by the script A) . Therefore the committing transaction rolls back.
  To achieve the recovery of the transaction failed and complete the operation by committing an appropriate value, which in this case is '2', the raised error needs to be captured and handled appropriately.



• The following depicts what happens when [Report error if expected value is unmatched or does not exist] is left unchecked.

  Sequence	Operation in script A	Operation in script B	The column value representing a version that is stored in the Amazon SimpleDB before the operation is performed.
  1	The version number retrieved from Amazon SimpleDB is '0'	The version number retrieved from Amazon SimpleDB is '0'	0
  2	Incrementing the value by 1 yields '1'	Incrementing the value by 1 yields '1'	0
  3	Incremented version '1' is written to the Amazon SimpleDB. ->succeeds		0
  4		Incremented version '1' is written to the Amazon SimpleDB. ->succeeds	1

  
  In the scenario above, the write operation performed in the script B overwrites the value the version '1', which has been committed by the transaction started in the script A, with the same value.
  This depicts the consistency being compromised between 2 scripts run concurrently.

Specification limitations

• Null is implicitly converted to an empty character.


• When a value assignment is made to an existing attribute, the attribute value is not inserted but rather updated.


• The order of the [Attribute list] returned in the 'Item selection dialog' is not guaranteed.


• Should write operation fail, items written cannot be rolled back.

Main exceptions

Notes

• Use HTTPS for communicating between Amazon SimpleDB and this adapter.


• All of the string values stored in the Amazon SimpleDB are UTF-8 encoded. Therefore each Japanese character is 3 bytes long.


• Limitation of Amazon SimpleDB with respect to the write item operation is as follows:

  Parameters	Limitations
  Maximum Item name length	1024 bytes
  Maximum Attribute name length	1024 bytes
  Maximum Attribute value length	1024 bytes
  Maximum number of attributes per item	256
  Maximum domain size	10GB
  Maximum number of attributes per domain	1 billion
  Maximum size of data handled in a batch operation	1MB



• About batch write operation
  • When neither [Skip item that failed to execute Put] nor the [Report error if expected value is unmatched or does not exist] is left unchecked, the write operation is performed in a batch.
  
  
  • The number of the items that can be written is 25.
  
  
  • Should the batch operation fail, writing all 25 items will fail.
  
  
  • Error will be raised, if the size of request made to Amazon SimpleDB exceeds 1MB which is the maximum size allowed for each batch write operation performed.
  
  
  • Error will be raised, if two or more of the same item name data exists in a batch.


• About write operation for which expected values are specified
  • The operation fails when the value specified in the [Expected name] and the existing value in the Amazon SimpleDB does not match or the attribute specified does not exists.
  
  
  • Error will be raised, if there are more than one value assigned to the attribute specified in the [Expected name].
  
  
  • If items that corresponds to the item names specified in the input data does not exists, the attribute specified in the [Expected name] is regarded as inexistent thereby an error is raised.