On 19 Jun 2014, at 14:54, Gunnar Morling <gunnar(a)hibernate.org> wrote:
> valueColumnName is something that I elected no to use because
NoSQL we bind to so far do not have a strong schema. And at at given segmentColumnValue
only correspond a single value. It would come and bite me if someone for the same segment
value had two different value column names to differentiate two different sequence.
> Would it really bite you? I think e.g. MongoDB could perfectly handle this case via
two different fields for the two sequences in the same document/segment.
The two definitions share the same options except for valueColumnName.
The table is roughly as followed
key | value1 | value2
1 | 10 | 24
What would be the MongoDB representation in your approach?
It would look like this:
"_id" : 1,
"value1" : 10,
"value2" : 24
So you would get the different sequence values from different fields of that same
document. But I wouldn't recommend to do so due to the potential contention on that
single record. Thus I'd raise at least a warning during bootstrap. As it's not
portable to stores with a fixed schema, I'd rather not support it at all, though, and
raise an error.
Exactly. But that’s the thing, AFAIK we do *not* store it that way today as we don’t use
valueColumnName. So today we store it like this
so 10 and 24 has to both live at the same time in sequence _value.