Creating a 1:M Parcel File buy joining

[MicahWarnock1]

In ArcMap I can join our parcel polygon file to our CAMA Assessors database by our GISID.  This gives me a 1:1 match.  If I right click and export the joined parcel polygon file the results are a 1:M stacked parcel export.  I use this tool to create a searchable parcel layer on our WebGIS.  Over the past week, I have tried to automate this through the model builder process with no success.  What I am looking for is how to perform a quick export(right click export in arcmap) in the model building process or a tool that functions the same.

[MichaelDumais]

Hi Micah,

How long does it take to export your parcel-join? 

I'm asuming you would be expecting a record count that would closely match the record count in your Assessor table.

It sounds like your Assessor table has a foreign key field that relates to geometry in your parcel layer to get the stacked parcels you describe, which are your multi-family units (Apartments & Condo scenario) that share the same geometry.    I too have a similar scenario where that stacked unit layer is important for our permiting software to return the correct tax roll parcel-id.

I've tried creating a view in the hopes of exporting a nightly layer with no success.  When I try to export the join of our parcel layer to tax roll table, I get a ridiculous amount of resulting polygons.

If you have performance issues with ArcMap, try using ArcPro, which is a 64 bit app.  It will use the internal memory of your work-station better than ArcDesktop apps.  I've noticed a difference using ArcPro vs ArcMap when exporting these type of joined scenarios.

Did you find a work-around for your scenario?

Cheers, Mike

[MicahWarnock1]

Hi Mike,

The join and export in my case does not take long at all and the returned product is exactly what I am looking for.  We implemented a GISID for the 1 to many parcels and I spent a fair amount of time making sure the links were correct.  I have not found a solution or workaround at the moment.  I have successfully created the join using model builder as well as exporting the data with the results I am looking for.  At that time I was running into an error after exporting it to python script due to workspace issues since in order to do the export you needed to be in an MXD environment.  I dropped the project for a bit as other things came up.  I have recently taught myself how to engage a workspace MXD in python which I think will be my solution, unfortunately, I did not make notes on how I did the join and export in model builder and can't quite replicate it again.  I think the combination of the workspace python code and remembering how I created the join will be my solution.

In regards to your one to many issues,  I have 9K parcels roughly and 11K assessor records.  When I export my records I end up with about 11K record+/-  how big of a jump do you get?  How do you join your assessor's record to your parcels?  Do you use a GISID?

One thing to look out for.  When you export your Tax Rolls/Assessors data make sure you are getting one line item for one parcel.  Some times when you try and get public information from CAMA systems you can select a column that has multiple lines such as deeds.  If a property has been sold 3 times you will have 3 line items.  Just a thought.

Best, MW

[MichaelDumais]

Thanks for responding Micah!

Yes, my scenario also has a common field that references a polygon.

I'm working with over 290K parcel/tax-roll records that reference over 190K

shapefiles via a shared field.

I get over 8 billion polygons and it takes 1/2 a day to run. Not going to

try to automate this craziness☺

I really wish I could just add a shape field to my tax roll table and do a

simple update like below. It works fine via SSMS and takes about 4 minutes

to push the geometry from the parcel layer into the tax roll table. But,

life is not so easy…

-- Create new Shape (Geometry) field and populate via an update statement

alter table taxroll add NULL;

-- Update the field via join

update a.[shape] = PARCEL_Layer.Shape

FROM taxroll a INNER JOIN

PARCEL_Layer b ON a.shapeid = b.shapeid

Are you working with a SDE geodatabase?

[MichaelDumais]

So far, I’ve automated (via a SQL agent job) a PAO download that gets all

the necessary files and performed various operations to get a

parcel feature class and taxroll table in a SQL server 2012-geodatabase.

Now, I'm experimenting with how to best merge the geometry and parcel

details into an export that can run in a reasonable amount of time 5-10

minutes.

Do you keep track of your geoprocessing window results?

You can copy paste the results out of your successful geoprocessing

operations to string together a script.

I can send you some of the scripts I've used in the past

[MichaelDumais]

Micah,

The geo-processing results window shows how I created the stacked parcel

scenario.

The dissolve and sql-view where the trial-an-error discoveries that

produced a parcel model I was looking to create.