topic Re: Personal Geodatabase Lockfile Won't Go Away in Python Questions

Personal Geodatabase Lockfile Won't Go Away

RobinPearce — Tue, 19 Jun 2012 10:15:27 GMT

Environment: ArcEditor/ArcMap/Arc Catalog 10.0 with Python 2.6.5

Problem: Running a script from ArcCatalog to populate an existing PGDB table from a CSV. The table gets filled perfectly but on completion of the script, the database lockfile(.ldb) doesn't disappear. Row and rows objects are both deleted in the script, so what is still holding the database? To clear the ldb, I have to close down ArcMap, then open the mdb in Access and then close it again. This defeats the whole object of convenience of staying in an ArcMap session to do a quick visual check of data just imported from CSV.

Here is my code:

import arcpy, csv

TypeOfData = str(arcpy.GetParameterAsText(0))
inputCSVfile = str(arcpy.GetParameterAsText(1))
FeatureClassTable = str(arcpy.GetParameterAsText(2))
row,rows = None,None

rows = arcpy.InsertCursor(FeatureClassTable)
fieldname = ["Last_Update","Last_Update_By","Feature_ID","Survey_ID","Survey_ID_Ref","Survey_Name","Feature_Name","Feature_Desc",
             "Symbology_Code","Symbology_Name","Line_ID","Line_Name","Easting","Northing","Depth","Altitude","Time_Stamp",
             "Heading","Remarks"]

inputTxtFile = open(inputCSVfile,"rb")
reader = csv.reader(inputTxtFile)
ID = 0

try:
  for inrow in inputTxtFile.readlines():
    if ID>0:
      itemstr = inrow.split(",")
      x = itemstr[10]
      y = itemstr[11]
      z = itemstr[12]
      m = 0
      point = arcpy.Point(x,y,z,m,ID)
      pnt = arcpy.PointGeometry(point)
      row = rows.newRow()
      row.setValue("Shape",pnt)
      row.setValue(fieldname[0],itemstr[0])
      row.setValue(fieldname[1],itemstr[1])
      if itemstr[2]!='': row.setValue(fieldname[3],itemstr[2])
      if itemstr[2]=='': row.setValue(fieldname[3],0)
      row.setValue(fieldname[4],itemstr[3])
      row.setValue(fieldname[5],itemstr[4])
      row.setValue(fieldname[6],itemstr[5])
      row.setValue(fieldname[7],itemstr[6])
      row.setValue(fieldname[8],itemstr[7])
      row.setValue(fieldname[10],itemstr[8])
      row.setValue(fieldname[11],itemstr[9])
      row.setValue(fieldname[12],itemstr[10])
      row.setValue(fieldname[13],itemstr[11])
      row.setValue(fieldname[14],itemstr[12])
      row.setValue(fieldname[15],itemstr[13])
      row.setValue(fieldname[16],itemstr[14])
      row.setValue(fieldname[17],itemstr[15])
      row.setValue(fieldname[18],itemstr[16])
      rows.insertRow(row)
      if ID%500==0: arcpy.AddMessage(ID)
    ID += 1
    if ID>100: break
  arcpy.AddMessage(ID-1)  

except:
  if not arcpy.GetMessages() == "":
    arcpy.AddMessage(arcpy.GetMessages(2))

finally:
  inputTxtFile.close()
  if row:
    del row
  if rows:
    del rows

What is really annoying, the same script runs in debug mode in PythonWin - as soon as I close PythonWin, the lockfile goes - without exiting my ArcMap session. But I don't want to use this method to run data.

What do I need to do?

Rob Pearce

Re: Personal Geodatabase Lockfile Won't Go Away

MathewCoyle — Tue, 19 Jun 2012 13:09:51 GMT

The does lock file actually stop you from doing anything? I know if FGDB lock files can persist after a session and have no impact on future sessions. I too have some lock files hanging around PGDBs after creation/processing and they don't seem impact on any analysis etc I want to do on them.

Re: Personal Geodatabase Lockfile Won't Go Away

JoshuaChisholm — Tue, 19 Jun 2012 16:51:08 GMT

I'd try (if you haven't already), removing EACH variable from memory until the lock file (hopefully) disappears. I'd start with typing "del row" and "del rows" into the console. Those lines should error since it looks like they are being properly removed in the script. Keep removing variables (like "del pnt"). "dir()" will give you the full list of all variable in memory.

Let me know if you find your culprit.
Good Luck!

Re: Personal Geodatabase Lockfile Won't Go Away

ChrisBater — Tue, 19 Jun 2012 18:18:46 GMT

I'd try (if you haven't already), removing EACH variable from memory until the lock file (hopefully) disappears. I'd start with typing "del row" and "del rows" into the console. Those lines should error since it looks like they are being properly removed in the script. Keep removing variables (like "del pnt"). "dir()" will give you the full list of all variable in memory.

Let me know if you find your culprit.
Good Luck!

Try "del arcpy" too.

Re: Personal Geodatabase Lockfile Won't Go Away

KevinBell — Tue, 19 Jun 2012 19:10:39 GMT

del the whole pgdb and use a fgdb!:p

Re: Personal Geodatabase Lockfile Won't Go Away

nimitz — Tue, 19 Jun 2012 19:22:17 GMT

What would be the difference between the PGDB and the FGDB?

Re: Personal Geodatabase Lockfile Won't Go Away

MathewCoyle — Tue, 19 Jun 2012 19:29:36 GMT

FGDB do not have a size limit. Support multi user viewing/editing. Topology, domains etc.

As of 10.0, there really is zero reason I know of to use a PGDB unless you need to tie it to Access for some archaic reason.

Re: Personal Geodatabase Lockfile Won't Go Away

RobinPearce — Wed, 20 Jun 2012 08:23:29 GMT

To all who responded to my question - many thanks.

Regarding use of PGDB, this decision unfortunately is client-driven - perhaps later on we can move to FGDB. The limitations with Access structure are well known to our company.

The existence of the lockfile does stop us editing the PGDB in any way, most importantly via ArcMap data editing. So it's a nuisance.

Joshua C and Chris B - thanks for your suggestions - I will try that out and report back!

Rob P
Gardline Geosurvey
Gt Yarmouth
Uk

Re: Personal Geodatabase Lockfile Won't Go Away

RobinPearce — Wed, 20 Jun 2012 14:54:28 GMT

Well, I just put in a 'del' statement for every variable and object name shown with dir(). Each delete seems to work ok. This just leaves the ones beginning with underscores plus 'pywin', which presumably only gets loaded with PythonWin anyway. Saved the script, ran directly. Still resolutely locked.

I know this must be possible because running the same script from the same Catalog window in ArcMap but using PythonWin via rightclick>debug, works. By the way, this is all on my local C drive, so no other users or network complications involved.

What is PythonWin doing to release the PGDB, that the straight script isn't?

Re: Personal Geodatabase Lockfile Won't Go Away

JoshuaChisholm — Wed, 20 Jun 2012 18:19:16 GMT

Rob, weird error. I was trying to find something wrong with your script, but it looks solid. Just one side note that shouldn't be related to this problem. Should the line "if ID>100: break" be changed to "if ID>100: continue"?

As for the lock file, does it disappear when you "del pywin"?

Re: Personal Geodatabase Lockfile Won't Go Away

RobinPearce — Sun, 12 Dec 2021 02:16:58 GMT

I've updated my 'finally' clause:

  finally:
    inputTxtFile.close()
    del row
    del rows
    del FeatureClassTable
    del ID
    del TypeOfData
    del fieldname
    del inputCSVfile
    del inputTxtFile
    del inrow
    del itemstr
    del m
    del pnt
    del point
    del reader
    del x
    del y
    del z
    del csv
    arcpy.RefreshCatalog("C:\GeneralWorkData\ArcGIS Test Data\OGP_BP\Python_work\BP8719_TestPop.mdb")
    del arcpy

'pywin' is not included because I'm trying to run this outside PythonWin. 'RefreshCatalog' is hardwired to my test PGDB after I stumbled over an old reference to this problem in an archived thread ("Python :: DeleteRows() and Release Object Reference", 9/27/04).

It don't work. I still have to crash out of Arcmap, then open the PGDB in Access then exit Access, to remove the lock. Surely there must be a way to do this properly! And I repeat, PythonWin manages to do it with Arcmap/Catalog still running.

ATTENTION ESRI: Are you still supporting PGDB file work? If you are, please have someone come out, review this thread, and tell me EXACTLY what I need to know to resolve this lockfile problem. Our company has already spent weeks trying to migrate from VBA, which is no longer supported, to Python. Are we wasting our time trying to run a Python script from an ArcMap/Catalog window?? THANK YOU!

Those of you exhorting us to switch to FGDB - can you assure us we won't have lockfile problems with that system?

Rob Pearce
(fed up with having to google every ESRI problem)

Re: Personal Geodatabase Lockfile Won't Go Away

RobinPearce — Fri, 22 Jun 2012 09:01:29 GMT

Right - when I run my script and then add the data layer to the map window, I am able to close ArcGIS (saving the mxd), and my precious ldb lockfile disappears immediately. I don't have to open an Access session to clear it.

Does this ring any bells with anyone?

I am trying to contact the people who created PythonWin, in case they know what their software is doing. You never know, I might actually get an answer!

Rob P