typedef struct _mongoc_bulk_operation_t mongoc_bulk_operation_t;

It is only valid to call mongoc_bulk_operation_execute() <> once. The mongoc_bulk_operation_t must be destroyed afterwards.

Bulk Write Operations <https://www.mongodb.com/docs/languages/c/c-driver/current/libmongoc/guides/bulk/>
mongoc_bulkwrite_t <>

If using MongoDB server 8.0+, prefer mongoc_bulkwrite_t <> over mongoc_bulk_operation_t <> to reduce network round trips.

mongoc_bulkwrite_t <> uses the bulkWrite server command introduced in MongoDB server 8.0. bulkWrite command supports insert, update, and delete operations in the same payload. bulkWrite supports use of multiple collection namespaces in the same payload.

mongoc_bulk_operation_t <> uses the insert, update and delete server commands available in all current MongoDB server versions. Write operations are grouped by type (insert, update, delete) and sent in separate commands. Only one collection may be specified per bulk write.