Data Import performance of retrieving source records

CREATE OR REPLACE VIEW source_records_view AS
SELECT records._id,
       json_build_object('recordId', records.jsonb ->> 'id',
                         'snapshotId', records.jsonb ->> 'snapshotId',
                         'recordType', records.jsonb ->> 'recordType',
                         'deleted', records.jsonb ->> 'deleted',
                         'additionalInfo', records.jsonb -> 'additionalInfo',
                         'metadata', records.jsonb -> 'metadata',
                         'rawRecord', raw_records.jsonb,
                         'parsedRecord', COALESCE(marc_records.jsonb))
         AS jsonb
FROM records
       JOIN raw_records ON records.jsonb ->> 'rawRecordId' = raw_records.jsonb ->> 'id'
       LEFT JOIN marc_records ON records.jsonb ->> 'parsedRecordId' = marc_records.jsonb ->> 'id'
WHERE records.jsonb ->> 'parsedRecordId' IS NOT NULL;

SELECT *
FROM diku_mod_source_record_storage.source_records_view
WHERE lower(f_unaccent(diku_mod_source_record_storage.source_records_view.jsonb ->> 'recordType')) LIKE
      lower(f_unaccent('MARC'))
LIMIT 50 OFFSET 0;

CREATE INDEX idx_btree_raw_record_id ON records USING BTREE ((jsonb ->> 'rawRecordId'));
CREATE INDEX idx_btree_parsed_record_id ON records USING BTREE ((jsonb ->> 'parsedRecordId'));

CREATE INDEX idx_btree_raw_records_id ON raw_records USING BTREE ((jsonb ->> 'id'));
CREATE INDEX idx_btree_marc_records_id ON marc_records USING BTREE ((jsonb ->> 'id'));

{
      "tableName": "records",
      "withMetadata": true,
      "pkColumnName": "_id",
      "generateId": false,
      "withAuditing": false,
      "uniqueIndex": [
        {
          "fieldName": "id",
          "tOps": "ADD"
        }
      ],
      "index": [
        {
          "fieldName": "id",
          "tOps": "ADD"
        }
      ],
      "foreignKeys": [
        {
          "fieldName": "rawRecordId",
          "targetTable": "raw_records",
          "tOps": "ADD"
        },
        {
          "fieldName": "parsedRecordId",
          "targetTable": "marc_records",
          "tOps": "ADD"
        }
      ]
    }