The ideal data for stratified sampling:
Stratified Random Sampling

The non-homogenous population is converted to homogenous groups/classes (strata); sample is drawn from each strata at random, in proportion to its size.
Applicable for large non-homogeneous population.
Gives a more representative sample than simple random sampling.
None of the categories is under or over-represented.
For example, In a population of 1000, a sample of 100 is to be drawn for Hemoglobin estimation; first convert non-homogenous population to homogenous strata (i.e. 700 males and 300 females), then draw 70 males and 30 females randomly respectively.
Heterogenous data
Homogenous data
Both
None