I wonder if/how that fails if you create the index before adding data:
CREATE TABLE test_path(path ltree); CREATE INDEX ON test_path USING GIST(path); INSERT INTO test_path SELECT * FROM comments.mp_comments;
Does that fail on a particular row ?
How many paths do you have and how long? How big is the table?
Yes, it fails.
I got permission and created a partial dump of the data with: CREATE TABLE lc AS SELECT id, path FROM comments.mp_comments WHERE length(path::text)>=500;
Attached. It is reproduces the error I get. One needs to create ltree extension first.
I understand, that issue most likely comes from the length of the ltree data stored in the columns. But error is a bit misleading…