1. A computer-implemented method comprising: maintaining a plurality of access-tracking data that respectively corresponds to a plurality of data rows that are managed by a database server; while the database server is executing in normal operation mode, performing steps comprising: automatically determining whether a first data row, of the plurality of data rows, has been recently accessed based on first access-tracking data, of the plurality of access-tracking data, that corresponds to the first data row; wherein the first data row is stored in first one or more data blocks; after determining that the first data row has been recently accessed, automatically removing the first data row from the first one or more data blocks and storing the first data row in one or more hot data blocks; wherein the one or more hot data blocks are designated for storing those data rows, from the plurality of data rows, that have been recently accessed; wherein the method is performed by one or more computing devices.