Description: This feature class contains historical data from the SanGIS PARCELS_ALL layer for tax parcels that have been "killed" by the San Diego County Assessor's office. That is, parcel numbers that are no longer used and/or valid. This data set is provided for the exclusive use of SanGIS JPA member users only and is not available to the general public. No data is available for parcels killed prior to October 2000. Data prior to March 14, 2011 is incomplete. See metadata description for the PARCELS_ALL dataset for more information on tax parcel information. Parcel History Feature Dataset Structure DescriptionThe Parcel History feature dataset contains the following four parts:The parcel history feature class (Parcel_Historical)The master property record (MPR) table (MPR_Historical)The property assessment record (PAR) table (PAR_Historical)Two relationships to relate the feature class to the MPR and PAR tables(Rel_ParcelHistoricalHasMPRHistorical) and (Rel_ParcelHistoricalHasPARHistorical)These components are published in the SanGIS data warehouse in a feature data set called Landbase_Historical.The feature class and tables are related by the APN. With one exception, the feature class and tables are copied exactly as they appear on the date the parcel is archived. The one exception is that SanGIS adds the attribute APNDISAPPEARED to each table and the feature class at the time the parcel is archived. This is discussed in more detail below. Attribute values in the feature class are as they appear in the SanGIS data warehouse at the time the parcel is archived. Some of the attributes are generated from overlays with other layers, some are taken from the MPR and some are from the PAR data. The source of the attribute is indicated in the descritption for that attribute.Parcel History Layer Creation MethodologyThis is a brief and simplified description of how the parcel history layer and related tables are created. The MPR file is received from the County Assessor once a week. Therefore this description generally describes the process that occurs on a weekly basis starting with receipt of the MPR file.MPR and PAR files from the previous week are copied to a temporary location.A comparison is made between the current week’s MPR and the previous week’s MPR.A list is generated of all APNs that appeared in the previous week but that are not in the current week’s MPR. This is the list of parcels to be archived (the archive list).For each parcel in the archive list:Parcel geometry and parcel feature class attributes are copied from the Parcels feature class in the SanGIS data warehouse to the Parcel_Historical feature class.MPR data is copied from the previous week’s MPR file to the MPR_Historical table.PAR data is copied from the previous week’s PAR file to the PAR_Historical table.The “APNDISAPPEARED”value is generated and added to each new record in the parcel history feature class and the MPR and PAR history tables.Data checks are done as needed and the history data is published to the SanGIS data warehouse.The APNDISAPPEARED value is the date of the MPR file in whichthe parcel first failed to appear. That is, if a parcel shows up in the MPR file received on 4/2/2011 and does not appear in the MPR file the next week (4/9/2011) the “APNDISAPPEARED”date will be 4/9/2011.Notes on Parcel History Layer Data Prior to March 14, 2011The process and data structure described above applies to all parcels archived by SanGIS starting on March 14, 2011. That is the date that sufficient processes were in place to archive retired parcels from the SanGIS data warehouse and include the complete MPR and PAR data provided by the County Assessor.Prior to March 14, 2011 parcels were not archived from the SanGIS data warehouse. However, a onetime project was initiated to collect available data from a set of CDs/DVDs of publicly available parcel data. In general these datasets were generated on a quarterly basis and represent a snapshot of the parcel base at the time they were created. However, the data on the CDs/DVDs included only the data that was made available to the public through SanGIS’data download site. This data excluded certain property characteristics and consisted only of the parcel feature class. In addition, the feature class changed from time to time so that not all attributes were available in each quarterly CD/DVD.The impact is that any parcels retired prior to March 14, 2011 will contain only a subset of the data available from that date forward. No MPR or PAR data is available for the parcels prior to March 14, 2011 and some attributes that are currently available to JPA members in the data warehouse are also not available (because they were not published to the public site).Furthermore, not all retired parcels were captured in the CDs/DVDs. This occurs because the CDs/DVDs were created only on a quarterly basis. If a parcel was created and then retired between the times the quarterly DVDs were created the parcel will not be on either the previous or current quarterly disc and so will not appear in the parcel history layer.For example, SanGIS has a snapshot of the parcel base created in January 2004 and another snapshot created in April 2004. Any parcel that was both created and retired between January and April 2004 will not appear in the parcel history layer.The CDs/DVDs held by SanGIS go back as far as October 2000. However, not all parcels in the County can be found on those discs back to that date. Some discs contained only parcels for the southern portion of the County, some only for the northern portion, and others only for the eastern part. The user must be aware that the retired parcel history prior to March 14, 2011 is incomplete and is not recoverable with the current data sources available to SanGIS.A Note About the APNDISAPPEARED AttributeThe APNDISAPPEARED attribute value is generated by SanGIS and added to the parcel history feature class and the MPR and PAR history tables. This value is an indicator only and in no way represents the date at which the parcel ceased to exist. The APNDISAPPEARED indicates only the date that SanGIS first discovered the parcel was no longer in the data source.For parcels archived after March 14, 2011 the APNDISAPPEARED value indicates the date that SanGIS first discovered the parcel was no longer in the MPR file. This does not mean that the parcel was retired on that date. The actual parcel retirement date can only be determined through a research of records at the County Assessor’s office.For parcels prior to March 14, 2011 the APNDISAPPEARED value will be the date of the CD or DVD that the parcel was first discovered missing. For example, if a parcel was on the January 2004 DVD but not on the April 2004 DVD the APNDISAPPEARED date would be shown as April 1, 2004 even though the parcel may have been retired anytime in the January to April time frame.In addition, the APNDISAPPEARED date for parcels archived between March 14, 2011 and April 1, 2011 will show as 4/1/2011.The user is cautioned that the APNDISAPPEARED date value only provides an indicator that the parcel existed at some time prior to that date.Parcels Without Geometry (possessory interest and others)From March 14, 2011 forward, any parcel found in the MPR will be archived. This includes possessory interest parcels that do not have geometry associated with them and thus are not in the current parcel layer at SanGIS. When archived, the MPR and PAR data are updated in the MPR and PAR history tables along with the APNDISAPPEARED date. However, there will be no corresponding entry in the Parcel_Historical feature class.This class of parcels may also include parcels that were created but never mapped by the County Assessor, were created and retired before SanGIS was able to create the geometry, or parcels that were created temporarily by the Assessor’s office for their business purposes. SanGIS is not able to determine the reason the parcel does not include geometry.
Service Item Id: c44ec082caf746ce96b1a7b641b939ea
Copyright Text: SanGIS using legal recorded data provided by the County Recorders and Assessor's Office. See the County ARCC website at https://arcc.sdcounty.ca.gov/Pages/default.aspx for more information about tax parcels