Reduce Processing Time for Update Cursor

Question

I am updating a field for a feature class that is on an enterprise geodatabase in SQL server. This is an ArcSDE connection.

My goal is to search for null values, and convert these to 0. The script is currently run through python on ArcCatalog 10.3. This is the part of the script in question:

fc= r"C:\Users\migrate\AppData\Roaming\ESRI\Desktop10.3\ArcCatalog\OZ@DB_MAPS.sde\DB.OZ.BaseMap\DB.OZ.PlantCenter"
arcpy.MakeFeatureLayer_management (fc, "fc_temp")   
with arcpy.da.UpdateCursor ("fc_temp", fieldID) as cursor:
    for row in cursor:
        if row[0] == None:
            row[0] = 0
            cursor.updateRow(row)

This dataset has about 20,000 entries, and the processing time is immense (over an hour at this point) for this part of the script. Is there a way to change the code to improve processing time for update cursors?

Answer 1

Use Select by Attribute to select all records with a Null value in the relevant field, then Calculate that field with the desired value. I might be missing something, but I can't see a reason to use an update cursor.

A possible solution would be:

fc= r"C:\Users\migrate\AppData\Roaming\ESRI\Desktop10.3\ArcCatalog\OZ@DB_MAPS.sde\DB.OZ.BaseMap\DB.OZ.PlantCenter"
arcpy.MakeFeatureLayer_management (fc, "fc_temp")
arcpy.SelectLayerByAttribute_management("fc_temp","NEW_SELECTION",'"fieldID" IS NULL')
arcpy.CalculateField_management("fc_temp","fieldID","0","PYTHON","")

Answer 2

You may want to use where_clause, so you are performing this function only on records with null values. This should speed up the script. Here is a sample script:

where_clause = 'fieldID IS NULL'
with arcpy.da.UpdateCursor ("fc_temp", fieldID, where_clause) as cursor:
    for row in cursor:
        row[0] = 0
        cursor.updateRow(row)