mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-12-09 08:10:09 +08:00
feac3364ed
documentation.
99 lines
3.2 KiB
Plaintext
99 lines
3.2 KiB
Plaintext
This is a R-Tree implementation using GiST.
|
|
Code (for PG95) are taken from http://s2k-ftp.cs.berkeley.edu:8000/gist/pggist/
|
|
and changed according to new version of GiST (7.1 and above)
|
|
|
|
All work was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov
|
|
(oleg@sai.msu.su). See http://www.sai.msu.su/~megera/postgres/gist
|
|
for additional information.
|
|
|
|
CHANGES:
|
|
Oct 10 MSD 2001
|
|
|
|
1. Implemented new linear algorithm for picksplit
|
|
ref. ( 'New Linear Node Splitting Algorithm for R-tree',
|
|
C.H.Ang and T.C.Tan )
|
|
|
|
Tue May 29 17:04:16 MSD 2001
|
|
|
|
1. Small fixes in polygon code
|
|
Thanks to Dave Blasby <dblasby@refractions.net>
|
|
|
|
Mon May 28 19:42:14 MSD 2001
|
|
|
|
1. Full implementation of R-tree using GiST - gist_box_ops,gist_poly_ops
|
|
2. gist_poly_ops is lossy
|
|
3. NULLs support
|
|
4. works with multi-key GiST
|
|
|
|
NOTICE:
|
|
This version will only work with PostgreSQL version 7.1 and above
|
|
because of changes in the function call interface.
|
|
|
|
INSTALLATION:
|
|
|
|
gmake
|
|
gmake install
|
|
-- load functions
|
|
psql <database> < rtree_gist.sql
|
|
|
|
REGRESSION TEST:
|
|
|
|
gmake installcheck
|
|
|
|
EXAMPLE USAGE:
|
|
|
|
create table boxtmp (b box);
|
|
-- create index
|
|
create index bix on boxtmp using gist (b gist_box_ops);
|
|
-- query
|
|
select * from boxtmp where b && '(1000,1000,0,0)'::box;
|
|
|
|
|
|
BENCHMARKS:
|
|
|
|
subdirectory bench contains benchmark suite.
|
|
Prerequisities: perl, DBI, DBD:Pg, Time::HiRes
|
|
|
|
cd ./bench
|
|
1. createdb TEST
|
|
2. psql TEST < ../box.sql
|
|
3. ./create_test.pl | psql TEST
|
|
-- change $NUM - number of rows in test dataset
|
|
4. ./bench.pl - perl script to benchmark queries.
|
|
Run script without arguments to see available options.
|
|
|
|
a)test without GiST index, using built-in R-Tree
|
|
./bench.pl -d TEST
|
|
b)test R-Tree using GiST index
|
|
./bench.pl -d TEST -g
|
|
|
|
|
|
RESULTS:
|
|
|
|
1. One interesting thing is that insertion time for built-in R-Tree is
|
|
about 8 times more than ones for GiST implementation of R-Tree !!!
|
|
2. Postmaster requires much more memory for built-in R-Tree
|
|
3. Search time depends on dataset. In our case we got:
|
|
+------------+-----------+--------------+
|
|
|Number boxes|R-tree, sec|R-tree using |
|
|
| | | GiST, sec |
|
|
+------------+-----------+--------------+
|
|
| 10| 0.002| 0.002|
|
|
+------------+-----------+--------------+
|
|
| 100| 0.002| 0.002|
|
|
+------------+-----------+--------------+
|
|
| 1000| 0.002| 0.002|
|
|
+------------+-----------+--------------+
|
|
| 10000| 0.015| 0.025|
|
|
+------------+-----------+--------------+
|
|
| 20000| 0.029| 0.048|
|
|
+------------+-----------+--------------+
|
|
| 40000| 0.055| 0.092|
|
|
+------------+-----------+--------------+
|
|
| 80000| 0.113| 0.178|
|
|
+------------+-----------+--------------+
|
|
| 160000| 0.338| 0.337|
|
|
+------------+-----------+--------------+
|
|
| 320000| 0.674| 0.673|
|
|
+------------+-----------+--------------+
|