ObjectNotImported error when importing exclusion constraints with GiST operators

[mattias-aims]

Bug description

When importing a database that contains exclusion constraints using GiST index with = and && operators on bigint and tstzrange columns, pgModeler fails with ObjectNotImported and UndefinedAttributeValue errors.

How to reproduce

On PostgreSQL 18.1:

1. Create a table with an exclusion constraint using GiST:

  CREATE EXTENSION IF NOT EXISTS btree_gist;

  CREATE TABLE test_table (
      id bigint NOT NULL,
      valid_period tstzrange NOT NULL DEFAULT tstzrange(now(), 'infinity')
  );

  ALTER TABLE test_table
      ADD CONSTRAINT test_table_id_valid_period_excl
      EXCLUDE USING gist (id WITH =, valid_period WITH &&);

2. Use pgModeler's "Import" feature to import from this database

3. The constraint fails to import

Expected behavior

Successfully import the exclusion constraint with proper operator resolution

Info about your desktop

• OS: Debian Linux
• Version: Linux debian 6.1.0-41-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.158-1 (2025-11-09) x86_64 GNU/Linux
• Window manager: Gnome
• pgModeler version: pgmodeler_plus-2.0.0-alpha-linux64.appimage
• Qt version: ?

Stacktrace / Debug info

  [ObjectNotImported] The object 'test_table.test_table_id_valid_period_excl' (Constraint),
  oid 'XXXXX', could not be imported due to one or more errors! Check the exception stack
  for more details. 'HINT:' if the object somehow references objects in 'pg_catalog' or 
  'information_schema' consider enabling the import of system/extension objects.

  [UndefinedAttributeValue] Attribute 'operator' with an undefined value in file
  '/home/user/pgModeler/schemas/xml/excelement.sch', line 28, column 23!

Raw attributes from error

  columns: [0:1]={1,2}
  ex-constr: true
  expressions: id WITH =, valid_period WITH &&)
  index-type: gist
  name: test_table_id_valid_period_excl
  no-inherit: true
  opclasses: [0:1]={16527,10078}
  operators: {410,3888}
  type: ex-constr

Additional info

The issue appears to be that pgModeler cannot resolve the operators (OIDs 410 for = on bigint, 3888 for && on tstzrange) when they come from the btree_gist extension. The opclasses reference OIDs that pgModeler doesn't recognize.