simon jacobi, 2018-04-29
current status of Temporal2 algebra:
*extendwith operator*
prototypical, naive implementation for mpoint x stream(ipoint) -> mpoint is working
sample query:
let t7c = [const mpoint value undef];
query t7c extendwith intstream (1,10) use [ fun (i:int) final ([const mpoint value ((("2000-01-01-00:00" "2000-01-01-00:01" TRUE FALSE) (0.0 0.0 1.0 1.0)) )] translate [[const duration value (0 60000)] * i, 1.0 * i , 1.0* i ]) ];
*Tools for testing*
Test operators for remote stream control implemented:
streamvalve / streamnext
*Open topics*
Operator to handle items in stream in separate transactions (c.f. ContinuousUpdate -> owntransactioninsert, but for StreamAlgebra -> use)
Interface for using Index-based access to Moving Types:
- How to update Index (if any):
-> within extendwith operator (register index at mpoint and trigger index update on change)
-> separate exendwithandupdateindex operator
---
2018-05-14
open:
- how to detect closing of database?
-> would be nice to persist mem before close
-> if second thread timer triggered writeback -> how to ensure we remain in consistent state?
--> does transaction prevent closing?
shared memory should be per database...
how to handle correct cleanup?
sequence 1 open db a, close a, open b, close b
sequence 2 open db a, ....... ......... close a
^ destroy mem b
^destroy mem a
Probably during Create we can check which (if any) database is open.
Then we may open the log... (-> can we detect, if it is already open?)
related:
how to export?
-> nl-rep: should not have internal id
-> nl->rep mem/log nono
but database:
- log + mpoint2 have id
object lifecycle:
-> Close: if last ref closed -> persist!? At least log?
-> Delete: mark deleted in log, persist log?
MPoint semantic -> no units =>? undefined
2018-07-26:
Pushing data to attributes seems to work single threaded and single process, but test:
- Assigning new MPoint to Tuple (id changes, backref remains)
- Deleting Tuple
- Deleting Relation
- Recreating Relation with same name (additional "unique id" required to detect this?)
Consider renaming StorageId to ReferenceId (or smth. like this)
ToDo:
- Refactor MemoryStructure (Map of ID -> Storage (vector<Unit>, bbox, ...))
- handle log cleanup!
- check locking for multiprocessing ("regular operation")
- check locking for multithreading (for push thread, if required)
- check transaction handling!
- extend to Attributes as named Objects
query pos_updates feed filter [ .DestTid = [const tid value 1] ] head[1] streamvalve ['Remote', 'a'] appendpositions ['trajectories2', 'DestTid', 'IPos','Trajectory'] count;
query streamnext ('a', 9);
query trajectories2;
restore database temporal2test from '/home/simon/secondo/bin/temporal2test';
query pos_updates feed filter [ .DestTid = [const tid value 1] ] head[1] appendpositions ['trajectories2', 'DestTid', 'IPos','Trajectory'] count;
