How would you represent a temporal many-to-many relation in SQL? Under non-temporal circumstances one would use a junction table (aka link/bridge/map) to connect the two sides. Is adding temporal tracking as simple as including a ValidStart and ValidEnd columns on the junction table? If you have done this, what issues (if any) did you r...
Has anyone found a simple, but effective way to extract date references from text? I've done a fair amount of searching for temporal extraction tools, but there isn't a lot out there. There are a few white papers, but it seems to fall into a subset of the whole semantic web thingy but not given much attention. I'm just looking for s...
I have a particularly difficult business constraint that I would like to enforce at the database level. The data is financial in nature, and so must be protected from inconsistencies to the nth degree – no trusting the business layer with this stuff. I use the word "temporal" somewhat loosely, meaning that I intend to control how an enti...
Hi, Can anyone supply some tips/pointers/links on how to implement a temporal state-table with NHibernate? I.e., each entity table has *start_date* and *end_date* columns that describe the time interval in which this this row is considered valid. When a user inserts a new entity, the *start_date* receives 'now' and the *end_date* will ...
Let's say you're implementing rails app for a snowboard rental store. A given snowboard can be in one of 3 states: away for maintenance available at store X on loan to customer Y The company needs to be able to view a rental history for a particular snowboard a particular customer The rental history needs to include temporal dat...
I have a series of timestamped on/off data in a table, representing on/off states, or the point at which a state "starts" 00:00:00 0 04:00:00 1 08:00:00 0 09:00:00 1 15:00:00 0 20:00:00 1 23:59:59 0 I need to calculate the total duration of (say) the ON state over a 24h period. In this simplified example total du...
I have an application that receives a number of datums that characterize 3 dimensional spatial and temporal processes. It then filters these datums and creates actions which are then sent to processes that perform the actions. Rinse and repeat. At present, I have a collection of custom filters that perform a lot of complicated spatial...
I am sure this was done 1000 times in 1000 different places. The question is I want to know if there is a better/standard/faster way to check if current "time" is between two time values given in hh:mm:ss format. For example, my big business logic should not run between 18:00:00 and 18:30:00. So here is what I had in mind: public stati...
Does anyone know of a library to handle events and recurring events likes the temporal expression libraries that exist for ruby like Runt (http://runt.rubyforge.org/) or TExp (http://texp.rubyforge.org/). Those libraries are perfect for what I need, but I need something in the >.NET Framework. Thanks! ...
I'm trying to wrap my head around this task and wondering if there is a standard way of doing this or some libraries that would be useful. Certain events are tracked and timed at several data sources S1 ... SN. The recorded information is the event type and timestamp. There may be several events of the same type sequentially or they may...
I'm curious if anyone has implemented or even knows of any bitemporal databases built on NoSQL platforms (e.g., riak). ...
I'm looking for temporal libraries for Java, i.e. libraries which allow to store multiple historical version of the same concept. I'm looking for a library which has an API to do something like: Instant i1 = Instant.valueOf("2010-01-01"); Instant i2 = Instant.valueOf("2010-01-02"); Attribute<String> a = .... a.setValue(i1, "String as ...