Hi, Konstantin > > 1) A "Versioned Temporal Table DDL on source" can only be joined on the > PRIMARY KEY attribute, correct? Yes, the PRIMARY KEY would be join key.
> > 2) Isn't it the time attribute in the ORDER BY clause of the VIEW definition > that defines > whether a event-time or processing time temporal table join is used? I think event-time or processing-time temporal table join depends on fact table’s time attribute in temporal join rather than from temporal table side, the event-time or processing time in temporal table is just used to split the validity period of versioned snapshot of temporal table. The processing time attribute is not necessary for temporal table without version, only the primary key is required, the following VIEW is also valid for temporal table without version. CREATE VIEW latest_rates AS SELECT currency, LAST_VALUE(rate) -- only keep the latest version FROM rates GROUP BY currency; -- inferred primary key > > 3) A "Versioned Temporal Table DDL on source" is always versioned on > operation_time regardless of the lookup table attribute (event-time or > processing time attribute), correct? Yes, the semantics of `FOR SYSTEM_TIME AS OF o.time` is using the o.time value to lookup the version of the temporal table. For fact table has the processing time attribute, it means only lookup the latest version of temporal table and we can do some optimization in implementation like only keep the latest version. Best Leonard
