They can't handle high cardinality. Imagine having millions of columns in the column-oriented database (70% of those columns are updated every second). Imagine that you have to add new columns all the time.
The main misconception about TSDB's is that it's just a data with timestamp. TSDB's has multi-dimentional data model, time is only one of the dimensions.
The main misconception about TSDB's is that it's just a data with timestamp. TSDB's has multi-dimentional data model, time is only one of the dimensions.