The present application relates to managing memory of a KLL sketch for a streaming set. A computer system allocates an initial amount of memory from a computer memory to a buffer of a KLL sketch data structure based on a sparse sketch size independent of a data type of the streaming set. The system allocates an incremental amount of memory greater than or equal to the initial amount of memory from the computer memory to the buffer in response to a size of the streaming set exceeding a supported stream size of the KLL sketch data structure. The system determines a number of levels of the KLL sketch data structure based on a total allocated amount of memory and a size of the data type of the streaming set. The system adds new elements from the streaming set to the KLL sketch data structure based on the number of levels.