I'm running an Alteryx workflow where I am pulling data from one database to another PostgreSQL database containg PostGIS. However, when I run the workflow and write the data to the database, I am getting an error saying:

Output Data (18) DataWrap2ODBC::SendBatch: ERROR: WKB structure does not match expected size!;¶Error while executing the query Insert into "table_name"("column_1","column_2","column_3","geom") Values (?,?,?,ST_GeomFromWKB(?,4326))

or in other words, the error is saying that WKB structure does not match expected size. There is a geometry or Spatial Object column in the database that I am trying to send to PostgreSQL..

I thought it might be the Spatial Object Field Size (it's too small) but when I increased it, it didn't do anything. Does anybody know why I am getting this error and how to fix it?

EDIT: This is how the geom table looks like that I am trying to insert into my PostgreSQL PostGIS table:


  • 1
    Can you show use your PostGIS destination table structure using \d table_name in psql? For Insert into "table_name"("column_1","column_2","column_3","geom") Values (?,?,?,ST_GeomFromWKB(?,4326), can you give use one sample for the value that should replace the question mark from ST_GeomFromWKB(?,4326)? Edit your question the infos. Thanks
    – ThomasG77
    Commented Jul 29, 2021 at 0:10
  • @ThomasG77 I edited my question, I didn't add everything because it's like 30000+ characters but I think you can get the gist of it with just that Commented Jul 29, 2021 at 17:23
  • Share the full geometry using pastebin.com or another code sharing site and give us the link, please. We can't troubleshoot without enough infos. It's not I do not want to help but just can't guess with your provided info at the moment.
    – ThomasG77
    Commented Jul 29, 2021 at 20:26
  • @ThomasG77 it looks like this: pastebin.com/EGwKtQFT Commented Jul 29, 2021 at 20:33
  • Not public: you copied the content but if not the owner not available to others. Change permissions to make it public. The issue with the pastebin can be reproduce if not connected.
    – ThomasG77
    Commented Jul 29, 2021 at 22:42

2 Answers 2


We are able to use the provided string. The original_string provided is at https://jsfiddle.net/ovr1798k/1/

We are able to process it using the original string wrapped between SELECT ST_AsText(ST_GeomFromWKB(E'\\x and )) We made it human readable using ST_AsText to check the result.

A full working demo to insert your data can be

  column_1 text,
  column_2 text,
  column_3 text,
  geom geometry(Polygon,4326)

-- We supposed your srid is 4326 but change it if necessary
-- Change <yourlongwkbstring> with your own wkb string
INSERT INTO table_name(column_1, column_2, column_3, geom)
VALUES ('content1', 'content2', 'content3',
ST_SetSrid(ST_GeomFromEWKB(decode('<yourlongwkbstring>', 'hex')), 4326);

You can see a full working code at https://gist.github.com/ThomasG77/dae8e8a76db4fc720fb18d261da4076f (because too long to fit in the answer here). You will need to adapt our solution as we did not use placeholders ?

  • Okay, I tried it but it looks like I get another error now saying: Output Data (18) DataWrap2ODBC::SendBatch: ERROR: Invalid endian flag value encountered.; ¶Error while executing the query Insert into "table_name"("column_1","column_2","column_3","geom") Values (?,?,?,?,ST_GeomFromWKB(?,4326)) Commented Jul 30, 2021 at 21:21
  • "You tried it" What did you try? To use the INSERT INTO table_name(... I provided using psql command line? It's to be sure before the ODBC part issue. It's because I also encountered the same ERROR: Invalid endian flag value encountered.; and has been able to solve it with my exact syntax. So, when you tell me you got the same error I already solved, I smell a wrong use of my recipe (but could be wrong as the error could come from ODBC driver or system endianness)
    – ThomasG77
    Commented Jul 30, 2021 at 22:01
  • Try ST_AsText(ST_SetSrid(ST_GeomFromEWKB(decode(v2.spectrum_band_geometries.geom, 'hex')), 4326)). I've considered that v2.spectrum_band_geometries.geom contain the same wkb as the one you provided in your sample.
    – ThomasG77
    Commented Jul 31, 2021 at 0:07
  • Now I'm getting another error when doing ST_AsText(ST_SetSrid(ST_GeomFromEWKB(decode(v2.spectrum_band_geometries.geom, 'hex')), 4326)), the error is: Error running PostSQL on "table_name": ERROR: data type text has no default operator class for access method "gist";¶Error while executing the query Commented Aug 2, 2021 at 18:00
  • St_AsText is for debugging purpose when using psql. Just use ST_SetSrid(ST_GeomFromEWKB(decode(v2.spectrum_band_geometries.geom, 'hex')), 4326)
    – ThomasG77
    Commented Aug 2, 2021 at 19:50

Finally got it to work thanks to someone's help. What I did when first calling the data is SELECT column_1, column_2, column_3, ST_AsEWKB(geom) FROM table_name and then for the Post-Create SQL statement in the workflow, I did the following SQL statement:

ALTER TABLE table_name ALTER COLUMN geom TYPE geometry(geometry,4326) USING (ST_GeomFromEWKB(geom));

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