Hi, I am writing some spatio-temporal function in postgis. Like, ST_Enters( obj_geom, boundary_geom, time t1,time t2)
For example- Does vehicle enters in ABC between time t1 to t2? Let us suppose, i take only one object geometry at a time and do compare then i could not produce the output because it is continous function of time i.e. Enters is made up of Disjoint -> Touches -> Inside . So, for creating this function, i require all the object's geometry before it go inside the function. So that it can call only once. My first problem is that create or replace function ST_Enters(????, geometry,timestamp,timestamp) returns boolean ............ Which kind of data type to be used because i have to catch more than 1000 rows and geometry doesn't work for it. So, Can anyone tell me which data type can be used to catch this? Second, How can i use this function in SQL? Because suppose i write query like select ST_Enters ( obj_geom, (select boundary_geom from boundary), '25/2/2011 12:23:32','26/2/2011') from vehicledata where vehicleid= 'XYZ'; and again it comes out to be one object geometry matches with boundary geometry, if i store the inbetween data in some temp table then it creates a lot of computation between the table and if it end up in between then table may contains some wrong data. So, How to use this function in SQL in continuous manner?? Thanks in advance.