Function GenerateRootTerm

pg_documentdb/src/opclass/gin_index_term.c:2193–2205

* This is the root term that all documents get when the indexed path exists. * We pick a term that points to a path that is illegal ('') * and give it to all terms. This allows us to answer questions * on complement sets (e.g. NOT operators) from the index. */

 * on complement sets (e.g. NOT operators) from the index.
 */
Datum
GenerateRootTerm(const IndexTermCreateMetadata *termData)
{
	pgbsonelement element = { 0 };
	element.path = "";
	element.pathLength = 0;
	element.bsonValue.value_type = BSON_TYPE_MINKEY;

	/* Can't mark this as metadata due to back-compat. This is okay coz this is legacy. */
	IndexTermMetadata termMetadata = IndexTermNoMetadata;
	return PointerGetDatum(SerializeBsonIndexTermCore(&element, termData,
													  termMetadata).indexTermVal);
}


Datum