Tom Lane <[EMAIL PROTECTED]> writes:
> Otherwise I think you really need a special datatype for time
> intervals and a GIST or r-tree index on it :-(.
You could actually take short cuts using expression indexes to do this. If it
works out well then you might want to implement a real data type to avoid the
overhead of the SQL conversion functions.
Here's an example. If I were to do this for real I would look for a better
datatype than the box datatype and I would wrap the whole conversion in an SQL
function. But this will serve to demonstrate:
stark=> create table interval_test (start_ts timestamp with time zone, end_ts
timestamp with time zone);
CREATE TABLE
stark=> create index interval_idx on interval_test using gist
(box(point(start_ts::abstime::integer, end_ts::abstime::integer) ,
point(start_ts::abstime::integer, end_ts::abstime::integer)));
CREATE INDEX
stark=> explain select * from interval_test where
box(point(now()::abstime::integer,now()::abstime::integer),point(now()::abstime::integer,now()::abstime::integer))
~ box(point(start_ts::abstime::integer, end_ts::abstime::integer) ,
point(start_ts::abstime::integer, end_ts::abstime::integer));
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Index Scan using interval_idx on interval_test (cost=0.07..8.36 rows=2
width=16)
Index Cond: (box(point((((now())::abstime)::integer)::double precision,
(((now())::abstime)::integer)::double precision),
point((((now())::abstime)::integer)::double precision,
(((now())::abstime)::integer)::double precision)) ~
box(point((((start_ts)::abstime)::integer)::double precision,
(((end_ts)::abstime)::integer)::double precision),
point((((start_ts)::abstime)::integer)::double precision,
(((end_ts)::abstime)::integer)::double precision)))
(2 rows)
--
greg
---------------------------(end of broadcast)---------------------------
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