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Thanks Markus for your help (in message "How the
R-Tree index works?"), but I guess, I should be more specific in my question.
I have the next situation:
1- A table (A) with data, for
example:
ID
| what |
time |
howmuch
--------------------------------------------------
1 |
Beer | 03-01-2002 |
10
2
| Whiskey | 06-01-2002 | 3
3 |
Beer | 09-01-2002 |
15
4 |
Galactic Beer | 11-02-2043 | 40
2- A table (T) with time intervals, for
example:
Interval
| Inittime | finishtime
-------------------------------------------------
50
| 01-01-2002 | 04-01-2002
51
| 05-01-2002 | 10-01-2002
52 | 12-01-2002 | 12-01-2050
I want to now if is better to use R-Tree or Gist,
if I want to know: "Howmuch" is in every "Interval", with something like
this:
SELECT Interval, sum(howmuch)
from A,T where time>=Inittime and time<finishtime group by
interval;
I will have:
Interval | howmuch
------------------------------
50
| 10
51
| 18
52
| 40
The problem is I have a lot of rows in A and T. Is
better for the database to use R-Tree? or GiST?
Should I use 2 index, one for each table (like a simple join situation)?
If I use R-Tree for a B-Tree task will I loss performance? And for GiST?
I have another case, more complex (not conceptually
complex, complex for the database), but I will post it when this more simple
question be answered. Thanks all and specially thanks Markus for his
help.
Andrés Sommerhoff
R-Tree:
"a spatial access
method which splits space with hierarchically nested boxes. Objects are
indexed in each box which intersects them. The tree is height-balanced."
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