MySQL 5.7 permits fractional seconds for
TIMESTAMP values, with up to
microseconds (6 digits) precision. See
Fractional Seconds in Time Values.
There may be problems replicating from a source server that understands fractional seconds to an older replica (MySQL 5.6.3 and earlier) that does not:
CREATE TABLEstatements containing columns that have an
fsp(fractional seconds precision) value greater than 0, replication fails due to parser errors.
Statements that use temporal data types with an
fspvalue of 0 work with statement-based logging but not row-based logging. In the latter case, the data types have binary formats and type codes on the source that differ from those on the replica.
Some expression results differ on source and replica. Examples: On the source, the
timestampsystem variable returns a value that includes a microseconds fractional part; on the replica, it returns an integer. On the source, functions that return a result that includes the current time (such as
UTC_TIMESTAMP()) interpret an argument as an
fspvalue and the return value includes a fractional seconds part of that many digits. On the replica, these functions permit an argument but ignore it.