SNB/IW: Updates for the type DateTime use Date inputs instead of DateTime

[whatsthecraic]

Hi,

In (all?) updates issued by the driver for the SNB/IW workload, when the specification expects a DateTime as parameter type, the driver always provide an instance of java.util.Date. Basically the time is not recorded. Is this behaviour implemented on purpose?

[szarnyasg]

The specification has been revised since and none of the Interactive read queries (complex, short) expect a DateTime. Dates can occur on the input and some queries return a DateTime, handled as a long (UNIX epoch) by the driver.

Related issue: #36

[szarnyasg]

Actually, the inserts indeed use Date parameters instead of DateTimes. Hah! See

• https://ldbcouncil.org/ldbc_snb_docs/workload-interactive-inserts.pdf
• https://github.com/ldbc/ldbc_snb_driver/blob/4916dcdf1552b9799113ccab6cdc27d3f94104f8/src/main/java/com/ldbc/driver/workloads/ldbc/snb/interactive/LdbcUpdate1AddPerson.java#L41

[szarnyasg]

This issue is still present in the codebase: https://github.com/ldbc/ldbc_snb_interactive_driver/blob/fe5bdf7cecd7c638599b05477debfc57e34108e6/src/main/java/org/ldbcouncil/snb/driver/workloads/interactive/LdbcUpdate1AddPerson.java#L42-L43

[szarnyasg]

Looked into this in more detail. java.util.Date stores timestamps with millisecond precision:

The class Date represents a specific instant in time, with millisecond precision.

The code had a confusing comment and a superfluous one - I removed them.