MaxRows defaults to 500
With the Recordset.MaxRows property you set the maximum number of rows that will be loaded into the resultset for the recordset.
By default the value is set to 500 rows (records).
You can change the limit by setting the MaxRows property before calling Recordset.ExecSql().
customers.MaxRows = 20000;
Topic Scale considerations discusses how to plan the amount of data to retrieve.
When a recordset contains multiple resultsets, MaxRows counts for each of the resultsets. For example:
multi_rs.MaxRows = 100;
multi_rs.Resultset1 will contain a maximum of 100 records
multi_rs.Resultset2 will contain a maximum of 100 records
The limit can be disabled by setting MaxRows to zero. We recommend you to never do this.