Function CollectionIdGetIndexNames

pg_documentdb/src/metadata/index.c:611–666

* CollectionIdGetIndexNames returns names of the indexes that collection * with collectionId has. If 'inProgressOnly' flag is true, it returns * only the index names whose build is in progress. */

 * only the index names whose build is in progress.
 */
List *
CollectionIdGetIndexNames(uint64 collectionId, bool excludeIdIndex, bool inProgressOnly)
{
	StringInfo cmdStr = makeStringInfo();
	appendStringInfo(cmdStr,
					 "SELECT array_agg((index_spec).index_name ORDER BY index_id) "
					 "FROM %s.collection_indexes WHERE collection_id = " UINT64_FORMAT,
					 ApiCatalogSchemaName, collectionId);

	if (inProgressOnly)
	{
		appendStringInfo(cmdStr,
						 " AND %s.index_build_is_in_progress(index_id)",
						 ApiInternalSchemaName);
	}
	else
	{
		appendStringInfo(cmdStr,
						 " AND (index_is_valid OR %s.index_build_is_in_progress(index_id))",
						 ApiInternalSchemaName);
	}

	if (excludeIdIndex)
	{
		appendStringInfo(cmdStr, " AND (index_spec).index_name != %s",
						 quote_literal_cstr(ID_INDEX_NAME));
	}

	bool isNull = true;
	bool readOnly = true;
	Datum resultDatum = ExtensionExecuteQueryViaSPI(cmdStr->data, readOnly,
													SPI_OK_SELECT, &isNull);
	if (isNull)
	{
		/* This collection does not contain any indexes */
		return NIL;
	}

	ArrayType *array = DatumGetArrayTypeP(resultDatum);

	/* error if any Datums are NULL */
	bool **nulls = NULL;

	Datum *elems = NULL;
	int nelems = 0;
	ArrayExtractDatums(array, TEXTOID, &elems, nulls, &nelems);

	List *indexNameList = NIL;

	for (int i = 0; i < nelems; i++)
	{
		indexNameList = lappend(indexNameList, TextDatumGetCString(elems[i]));
	}

	return indexNameList;
}