Function WriterSingleQual

pg_documentdb/src/explain/documentdb_explain.c:411–510

static void
WriterSingleQual(pgbson_writer *writer, Expr *qual)
{
	List *args;
	const MongoQueryOperator *operator = GetMongoQueryOperatorFromIndexOrRuntimeExpr(
		(Node *) qual, &args);

	if (list_length(args) != 2 || operator->operatorType == QUERY_OPERATOR_UNKNOWN)
	{
		/* Check if it's for the shard_key_value or object_id */
		if (IsA(qual, OpExpr))
		{
			OpExpr *opExpr = (OpExpr *) qual;
			if (IsA(linitial(opExpr->args), Var))
			{
				Var *firstVar = (Var *) linitial(opExpr->args);
				if (firstVar->varno == INDEX_VAR &&
					firstVar->varattno ==
					DOCUMENT_DATA_TABLE_SHARD_KEY_VALUE_VAR_ATTR_NUMBER &&
					firstVar->vartype == INT8OID)
				{
					return;
				}
				else if (firstVar->varno == INDEX_VAR &&
						 firstVar->varattno ==
						 DOCUMENT_DATA_TABLE_OBJECT_ID_VAR_ATTR_NUMBER &&
						 firstVar->vartype == BsonTypeId())
				{
					/* Object_Id qual - write as object_id filter */
					Expr *secondArg = lsecond(opExpr->args);
					if (IsA(secondArg, Const))
					{
						Const *secondConst = (Const *) secondArg;
						pgbsonelement secondElement;
						PgbsonToSinglePgbsonElementWithCollation(DatumGetPgBson(
																	 secondConst->
																	 constvalue),
																 &secondElement);

						const char *operatorName = "$unknown";
						if (opExpr->opno == BsonEqualOperatorId())
						{
							operatorName = "$eq";
						}
						else if (opExpr->opno == BsonLessThanOperatorId())
						{
							operatorName = "$lt";
						}
						else if (opExpr->opno == BsonLessThanEqualOperatorId())
						{
							operatorName = "$lte";
						}
						else if (opExpr->opno == BsonGreaterThanOperatorId())
						{
							operatorName = "$gt";
						}
						else if (opExpr->opno == BsonGreaterThanEqualOperatorId())
						{