DatumToHLC performs the conversion from a Datum to an HLC timestamp.

Eval evaluates the timestamp argument to an AS OF SYSTEM TIME query.

IsFollowerReadTimestampFunction determines whether the AS OF SYSTEM TIME clause contains a simple invocation of the follower_read_timestamp function.

AsOf is when the DatumToHLC() is used for an AS OF SYSTEM TIME statement.

FollowerReadTimestampExperimentalFunctionName is the name of the old "experimental_" function, which we keep for backwards compatibility.

FollowerReadTimestampFunctionName is the name of the function which can be used with AOST clauses to generate a timestamp likely to be safe for follower reads.

ReplicationCutover is when the DatumToHLC() is used for an ALTER VIRTUAL CLUSTER ..

Split is when the DatumToHLC() is used for a SPLIT statement.

WithMaxStalenessFunctionName is the name of the function that can be used with AOST clauses to generate a bounded staleness at a maximum interval.

WithMinTimestampFunctionName is the name of the function that can be used with AOST clauses to generate a bounded staleness at a fixed timestamp.

OptionAllowBoundedStaleness signifies Eval should not error if a bounded staleness query is found.

DatumToHLCUsage specifies which statement DatumToHLC() is used for.

EvalOption is an option to pass into Eval.