Managing Crosswalk Dates
Learn how to capture the date and time when data updates are propagated into Reltio platform by a source.
A crosswalk provides a collection of timestamp fields that enable a developer to granularly capture the date and time when different kinds of updates were propagated into Reltio by the source. These are described in this section.
Refer to the following image of an expanded crosswalk in the UI:
createDate (Crosswalk)
| Purpose: | Create Date is intended to represent the date the source object was created within the source system. | 
| Recommended Use: | If the source system provides the create date of the object
                                    (usually represented as a datetime field within the record),
                                    then it is ideal to write this date in the
                                        createDate field of the Reltio object’s
                                    crosswalk. | 
| Can be written? | Yes | 
| Can be overwritten? | Yes | 
| How it is set? | During create or override request,
                                        createDate can be provided in the crosswalk
                                    section of the post. If the Create Date is not provided
                                    during the first post, the API will write the current timestamp
                                    as the Create Date. Upon subsequent updates to the
                                    crosswalk, the Create Date can be overwritten via the
                                    crosswalk section of the post, but if it is not provided, the
                                        Create Date is left as-is. | 
| How it is returned? | createDate is always returned in the
                                    crosswalk section of a retrieved object.  | 
| Effect on Survivorship: | None | 
updateDate (Crosswalk)
| Purpose: | Also commonly known as ‘Last Update Date’,
                                        updateDate is intended to represent the
                                    date the record was updated in the source system. Recency, as a
                                    concept in an OV rule, is trying to assess which source system
                                    has the most recent information about the data. In order to do
                                    this faithfully, Reltio needs to know the most recent timestamp
                                    of the data, from the perspective of each source. | 
| Recommended Use: | If the source system provides the Update Date of the object
                                    (usually represented as a datetime field within the source
                                    record), then it is ideal to write this date in the
                                        updateDate field of the Reltio object’s
                                    crosswalk. | 
| Can be written? | Yes | 
| Can be overwritten? | Yes | 
| How it is set? | During a create or an override request,
                                        updateDate is provided in the
                                        crosswalk section of the post. If the
                                        Update Date is not provided, both the Update
                                        Date and the Create Date will be the same. OV
                                    recency rules will be ineffective in determining which attribute
                                    from a collection is the most recent. For more information, see topic Attribute and Crosswalk Update Dates.Note: When you update a crosswalk, its  updateDate plays a crucial role in determining whether the crosswalk remains active. If you explicitly set an updateDate that differs from the existing value—and it's not a partial override—the system reactivates the crosswalk. However, if you also want to set a deleteDate, you must specify it directly. Otherwise, the crosswalk remains enabled. | 
| How it is returned? | updateDate is always returned in the
                                    crosswalk section of a retrieved object.  | 
| Effect on Survivorship: | The OV Recency rule considers the updateDate
                                    of a crosswalk when determining which attribute from a
                                    collection will be the most recent:
                                     | 
You can modify the updateDate parameter of crosswalks in the
                following two ways:
- By using the 
PUT .../entities/{entityId}/crosswalks/{crosswalkId}/updateDaterequest. - By using the 
POST .../entitiesrequest and performing one of the following steps:- Update any attribute that has a crosswalk and for which you want to update the
                                
updateDatefield. - Do not change any attribute of the entity and use the
                                
partialOverrideoption. Provide all the existing attribute values that belong to the crosswalk. - Do not change any attribute of the entity and do not use the
                                
partialOverrideoption. Provide theupdateDatefield for the crosswalk inside the request body. 
 - Update any attribute that has a crosswalk and for which you want to update the
                                
 
deleteDate (Crosswalk)
| Purpose: | deleteDate (end-date) is intended to
                                    represent the date an object that previously existed in the
                                    source was removed or set to Inactive. In an ideal scenario,
                                    objects in the source are soft-deleted, meaning they remain in
                                    the source and remain in the files that continue to be extracted
                                    from the source, but they contain a delete or
                                        inactive date that articulates when the
                                    source system declares the record to be deleted or inactive. In
                                    this way, the date can be written into the object’s crosswalk
                                    within Reltio, and Reltio can treat the crosswalk accordingly.
                                 | 
| Recommended Use: | When populated, Reltio considers this to be a end-date of the
                                    crosswalk. In the UI, the current data represented by the
                                    crosswalk no longer has a solid color in the background but
                                    instead is shown as an outlined box with no background color.
                                    Additionally a “red circle with a slash” is shown to the right
                                    of the crosswalk. The crosswalk will no longer accept updates
                                    from the source. In terms of the survivorship strategy, the data
                                    associated with this crosswalk will be ignored by all OV rules.
                                         Note: When all crosswalk dates within an entity have been
                                        end dated, the entire entity will be end dated by the API.
                                        End dating a crosswalk has no effect on ability to link
                                        transactions to it.  
                                 | 
| Can be written? | Yes | 
| Can be overwritten? | Yes, and it can be removed thus re-enabling the crosswalk for
                                    active use again.  Note: You can remove this crosswalk only  via Data Loader.  | 
| How it is set? | During create or override request, the Delete Date can be provided in the crosswalk section of the post. If not provided, then API will not set is automatically. | 
| How it is returned? | The Delete Date is returned with crosswalk for an
                                    object only if is it set.  Note: If the style of extraction from
                                        the source does not provide deleted records with delete
                                        dates, but rather just removes them from the extract
                                        entirely, it may be useful to perform delta detection on the
                                        extract to determine which records have been removed since
                                        the last extract, and then craft your load strategy to set
                                        the delete date of the object’s crosswalk in Reltio
                                        accordingly. 
                                 | 
| Effect on Survivorship: | None | 
Behavior of Cleanser
After the deleteDate parameter is set for the source crosswalk, the
                cleanser is initiated and all the values of the source crosswalk are converted to
                non-OV values and the cleanse process is initiated.
In the cleanse configuration, when the ovOnly is set to
                false, the source crosswalks values participate in the cleansing process. The
                cleanser adds or updates the cleanse input values with values from the cleanser
                crosswalk.
In the cleanse configuration, when the ovOnly is set to true,
                the source crosswalks values do not participate in the cleansing process. Existing
                cleanser crosswalk values are removed as there are no values in the source.
Crosswalk singleAttributeUpdateDate
| Purpose: | An attribute holds values contributed by and associated with
                                    various crosswalks. Generally, the timestamp. This capability
                                    enables the ability to store the timestamp of a specific value
                                    in an attribute, if the value has been updated more recently and
                                    separately (via a partial override) than that of the
                                        updateDate of the crosswalk that
                                    contributes it. These are represented as a collection on a
                                    crosswalk.  | 
| Recommended Use: | Usually used during a partial override operation, when one or just a few attributes from a crosswalk are being updated. Example, suppose a First Name field contains Bob, Bobby, Roberto, all having been written by a normal post in the past. A user goes into Edit mode for the profile and changes Roberto to Robert, and saves the record. Bob and Bobby will not be represented in the collection and their timestamp is inferred from that of the crosswalk. Robert however, having been just updated will be represented in the collection with a current timestamp that is greater than that of the crosswalk. The Recency rule will respect the timestamp of Robert found in the collection as the greater of it and the one found in the crosswalk. | 
| Can be written? | Yes | 
| Can be overwritten? | No, Reltio platform sets this timestamps automatically when either partial override happens or an attribute is created or updated. | 
| How it is set? | 
                                    
  | 
| How it is returned? | singleAttributeUpdateDates is a property of
                                    a crosswalk that is always returned (might be empty). It will
                                    have elements if specific attributes were updated through
                                    partial override or through attributes creates or
                                    updates. | 
| Effect on Survivorship: | The OV Recency rule considers the updateDate
                                    of a crosswalk when determining which attribute from a
                                    collection will be the most recent.
                                     | 
sourcePublishDate (Source or crosswalk level)
| Purpose: | sourcePublishDate is intended to represent
                                    the date of an extract from a source system. In this way, Reltio
                                    platform makes it easy to document the latest extract date that
                                    is represented for the data in Reltio platform. When you write
                                    this date, you can do so at the source level, and/or you can
                                    write it at the crosswalk level. In all cases, when you retrieve
                                    an object, Reltio platform returns only one
                                        sourcePublishDate and it is based on an
                                    internal calculation that returns the max of both dates found.  | 
| Recommended Use: | If a full extract is loaded, then user must set the
                                        sourcePublishDate at the source level.
                                    However if only a small set of records have been subsequently
                                    re-extracted, then the sourcePublishDate at the
                                    crosswalk level must be set for those records. Example: Suppose
                                    on April 1, 2017 the usual monthly extract from System “CRM” has
                                    been received and it has 99,000 records. You would load the file
                                    into Reltio platform and set the
                                        sourcePublishDate at the source level to
                                    04/01/2017. This is a single PUT operation.
                                    Then on April 5, a small set of 3 records were extracted,
                                    separately from the full set and loaded into Reltio platform.
                                    You must set the sourcePublishDate for these 3
                                    records to 04/05/2017 but do so at the crosswalk level. In this
                                    way when you retrieve any of these 3 records, they will show
                                    having been published on Apr 5. But if you retrieve any of the
                                    99,000 other than these 3, they will reveal a
                                        sourcePublishDate of Apr 1. | 
| Can be written? | Yes | 
| Can be overwritten? | Yes | 
| How it is set? | 
                                    
  | 
| How it is returned? | This property is returned only as an attribute in an object’s set of crosswalk dates. | 
| Effect on Survivorship: | The OV Recency rule considers the
                                        sourcePublishDate of an attribute value
                                    when determining which attribute from a collection will be the
                                    most recent.
                                    
                                 | 
Object createDate
| Purpose: | Each object carries the date that the object was first instantiated by Reltio platform and given a unique ID. This date is not shown in the UI but can be used in a search and can be retrieved as the createDate property of an object. The date is read-only and will never be overwritten. | 
| Recommended Use: | Initially, Reltio platform will automatically set this date to the date the entity was created in Reltio. During subsequent updates, this timestamp is not changed. | 
| Can be written? | No | 
| Can be overwritten? | No | 
| How it is set? | It is set automatically by Reltio platform when a record is created. | 
| How it is returned? | Create Date is always returned for an object. | 
| Effect on Survivorship: | None | 
Object updateDate
| Purpose: | Each object carries a date when it was most recently updated in Reltio platform from any source. This date is not available in the UI but can be used in a search and can be retrieved as the updateDate property of an object. The date is read-only and will never be overwritten. | 
| Recommended Use: | Initially, Reltio platform will automatically set this date to the date the entity was created in Reltio. During subsequent updates, Reltio platform will automatically set this date to the date the object was updated. | 
| Can be written? | No | 
| Can be overwritten? | No | 
| How it is set? | It is set automatically by Reltio platform when an object is created or updated. | 
| How it is returned? | Update Date is always returned for an object. | 
| Effect on Survivorship: | None | 
Detail on the Recency OV Rule
When the recency rule is chosen for an attribute, it tries to find the most recent value from each of the contributing crosswalks. But from each crosswalk, it considers the update date, the sourcePublishDate and individual attribute update date, and chooses the most recent from among those dates, as the recency date for that crosswalk.