The logical timestamp is represented by a 64-bit integer.
LOGICAL_TIMESTAMP_TYPE_STRING
3
The logical timestamp is represented by a string with a chronological timestamp for order comparison.
LOGICAL_TIMESTAMP_TYPE_INTEGER_AND_STRING
4
The logical timestamp is represented by a 64-bit integer and a string with a chronological timestamp for order comparison. Two logical timestamps i.e. combination of eLogicalTimestampTypeInteger and eLogicalTimestampTypeString.