Note – this will take a LONG time to run – quite possibly many hours - on a big dataset as it drops and recreates the index using different parameters – sledgehammer approach, but given the permutations available in SQL server spatial indexing and the level of confusion around optimising – this is the empirical approach.
lifted from here: http://stackoverflow.com/questions/2920948/selecting-a-good-sql-server-2008-spatial-index-with-large-polygons
Basically crate the SPROC listed at the bottom, then setup some example calls (3 or 4 different ones to minimise caching artefacts)
Then set it running and go on holiday …
Setup your parameters:
DECLARE @g1 VARCHAR(MAX)
SET @g1 = 'GEOMETRY::STGeomFromText(''POLYGON((252783.989267352 461095.507712082,260134.010732648 461095.507712082,260134.010732648 465068.492287918,252783.989267352 465068.492287918,252783.989267352 461095.507712082))'', 28992)'
DECLARE @g2 VARCHAR(MAX)
SET @g2 = 'GEOMETRY::STGeomFromText(''POLYGON((5580.146375 5340.100667,655613.186375 5340.100667,655613.186375 1219811.501845,5580.146375 1219811.501845,5580.146375 5340.100667))'',28992)'
exec sp_tune_spatial_index 'OBSVEG.OBS_Locations' ,'sidx_OBS_Locations_geom',2,8,@g1,@g2
Create Stored procedure:
N.B. Assumes geometry field is called geom
N.B. You MUST modify the SPROC to use extents for your SRID
USE [CMSI-OBSVEG]
GO
/****** Object: StoredProcedure [dbo].[sp_tune_spatial_index] Script Date: 10/01/2013 11:35:27 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[sp_tune_spatial_index]
(
@tabnm VARCHAR(MAX), -- This parameter stores the name of the spatial table for which you are tuning the index
@idxnm VARCHAR(MAX), -- This parameter stores the name of the spatial index of the named table
@min_cells_per_obj INT, -- Minimum Cells Per Object to test on. Suggested to start at 2.
@max_cells_per_obj INT, -- Maximum Cells Per Object to test on.
/* The test requires two geometry instances to use in test query 1 and 2.
The first one should cover the area of default extent. The second should
cover an area roughly the size of the area shown when zoomed in, panning
around. It is required that the variable store a string that will create
the geometry instance since this will be done within the procedure and
cannot be a variable of type: GEOMETRY. The SRID of these instances must
match that of the table you are testing. */
@testgeom1 VARCHAR(MAX), -- This parameter stores the first geometry instance creation string that will be used in the test
@testgeom2 VARCHAR(MAX) -- This parameter stores the second geometry instance creation string that will be used in the test
)
AS
SET NOCOUNT ON;
/* Prior to running this procedure, two tables are required. These tables are
created here to prepare for running the procedure. */
PRINT 'Checking for required tables...'
IF EXISTS(SELECT 1 FROM sysobjects WHERE name IN ('cell_opt_perm', 'spat_idx_test_result'))
BEGIN
PRINT '... The "cell_opt_perm" and "spat_idx_test_result" tables exist.'
END
ELSE
BEGIN
PRINT '... Creating "cell_opt_perm" and "spat_idx_test_result" tables.'
CREATE TABLE cell_opt_perm(
[perm_id] [smallint] NOT NULL,
[permutation] [nvarchar](4) NOT NULL,
[level1] [nvarchar](6) NOT NULL,
[level2] [nvarchar](6) NOT NULL,
[level3] [nvarchar](6) NOT NULL,
[level4] [nvarchar](6) NOT NULL
)
INSERT INTO cell_opt_perm ([perm_id], [permutation], [level1], [level2], [level3], [level4])
VALUES (1,'LLLL','LOW','LOW','LOW','LOW'),
(2,'LLLM','LOW','LOW','LOW','MEDIUM'),
(3,'LLLH','LOW','LOW','LOW','HIGH'),
(4,'LLML','LOW','LOW','MEDIUM','LOW'),
(5,'LLMM','LOW','LOW','MEDIUM','MEDIUM'),
(6,'LLMH','LOW','LOW','MEDIUM','HIGH'),
(7,'LLHL','LOW','LOW','HIGH','LOW'),
(8,'LLHM','LOW','LOW','HIGH','MEDIUM'),
(9,'LLHH','LOW','LOW','HIGH','HIGH'),
(10,'LMLL','LOW','MEDIUM','LOW','LOW'),
(11,'LMLM','LOW','MEDIUM','LOW','MEDIUM'),
(12,'LMLH','LOW','MEDIUM','LOW','HIGH'),
(13,'LMML','LOW','MEDIUM','MEDIUM','LOW'),
(14,'LMMM','LOW','MEDIUM','MEDIUM','MEDIUM'),
(15,'LMMH','LOW','MEDIUM','MEDIUM','HIGH'),
(16,'LMHL','LOW','MEDIUM','HIGH','LOW'),
(17,'LMHM','LOW','MEDIUM','HIGH','MEDIUM'),
(18,'LMHH','LOW','MEDIUM','HIGH','HIGH'),
(19,'LHLL','LOW','HIGH','LOW','LOW'),
(20,'LHLM','LOW','HIGH','LOW','MEDIUM'),
(21,'LHLH','LOW','HIGH','LOW','HIGH'),
(22,'LHML','LOW','HIGH','MEDIUM','LOW'),
(23,'LHMM','LOW','HIGH','MEDIUM','MEDIUM'),
(24,'LHMH','LOW','HIGH','MEDIUM','HIGH'),
(25,'LHHL','LOW','HIGH','HIGH','LOW'),
(26,'LHHM','LOW','HIGH','HIGH','MEDIUM'),
(27,'LHHH','LOW','HIGH','HIGH','HIGH'),
(28,'MLLL','MEDIUM','LOW','LOW','LOW'),
(29,'MLLM','MEDIUM','LOW','LOW','MEDIUM'),
(30,'MLLH','MEDIUM','LOW','LOW','HIGH'),
(31,'MLML','MEDIUM','LOW','MEDIUM','LOW'),
(32,'MLMM','MEDIUM','LOW','MEDIUM','MEDIUM'),
(33,'MLMH','MEDIUM','LOW','MEDIUM','HIGH'),
(34,'MLHL','MEDIUM','LOW','HIGH','LOW'),
(35,'MLHM','MEDIUM','LOW','HIGH','MEDIUM'),
(36,'MLHH','MEDIUM','LOW','HIGH','HIGH'),
(37,'MMLL','MEDIUM','MEDIUM','LOW','LOW'),
(38,'MMLM','MEDIUM','MEDIUM','LOW','MEDIUM'),
(39,'MMLH','MEDIUM','MEDIUM','LOW','HIGH'),
(40,'MMML','MEDIUM','MEDIUM','MEDIUM','LOW'),
(41,'MMMM','MEDIUM','MEDIUM','MEDIUM','MEDIUM'),
(42,'MMMH','MEDIUM','MEDIUM','MEDIUM','HIGH'),
(43,'MMHL','MEDIUM','MEDIUM','HIGH','LOW'),
(44,'MMHM','MEDIUM','MEDIUM','HIGH','MEDIUM'),
(45,'MMHH','MEDIUM','MEDIUM','HIGH','HIGH'),
(46,'MHLL','MEDIUM','HIGH','LOW','LOW'),
(47,'MHLM','MEDIUM','HIGH','LOW','MEDIUM'),
(48,'MHLH','MEDIUM','HIGH','LOW','HIGH'),
(49,'MHML','MEDIUM','HIGH','MEDIUM','LOW'),
(50,'MHMM','MEDIUM','HIGH','MEDIUM','MEDIUM'),
(51,'MHMH','MEDIUM','HIGH','MEDIUM','HIGH'),
(52,'MHHL','MEDIUM','HIGH','HIGH','LOW'),
(53,'MHHM','MEDIUM','HIGH','HIGH','MEDIUM'),
(54,'MHHH','MEDIUM','HIGH','HIGH','HIGH'),
(55,'HLLL','HIGH','LOW','LOW','LOW'),
(56,'HLLM','HIGH','LOW','LOW','MEDIUM'),
(57,'HLLH','HIGH','LOW','LOW','HIGH'),
(58,'HLML','HIGH','LOW','MEDIUM','LOW'),
(59,'HLMM','HIGH','LOW','MEDIUM','MEDIUM'),
(60,'HLMH','HIGH','LOW','MEDIUM','HIGH'),
(61,'HLHL','HIGH','LOW','HIGH','LOW'),
(62,'HLHM','HIGH','LOW','HIGH','MEDIUM'),
(63,'HLHH','HIGH','LOW','HIGH','HIGH'),
(64,'HMLL','HIGH','MEDIUM','LOW','LOW'),
(65,'HMLM','HIGH','MEDIUM','LOW','MEDIUM'),
(66,'HMLH','HIGH','MEDIUM','LOW','HIGH'),
(67,'HMML','HIGH','MEDIUM','MEDIUM','LOW'),
(68,'HMMM','HIGH','MEDIUM','MEDIUM','MEDIUM'),
(69,'HMMH','HIGH','MEDIUM','MEDIUM','HIGH'),
(70,'HMHL','HIGH','MEDIUM','HIGH','LOW'),
(71,'HMHM','HIGH','MEDIUM','HIGH','MEDIUM'),
(72,'HMHH','HIGH','MEDIUM','HIGH','HIGH'),
(73,'HHLL','HIGH','HIGH','LOW','LOW'),
(74,'HHLM','HIGH','HIGH','LOW','MEDIUM'),
(75,'HHLH','HIGH','HIGH','LOW','HIGH'),
(76,'HHML','HIGH','HIGH','MEDIUM','LOW'),
(77,'HHMM','HIGH','HIGH','MEDIUM','MEDIUM'),
(78,'HHMH','HIGH','HIGH','MEDIUM','HIGH'),
(79,'HHHL','HIGH','HIGH','HIGH','LOW'),
(80,'HHHM','HIGH','HIGH','HIGH','MEDIUM'),
(81,'HHHH','HIGH','HIGH','HIGH','HIGH')
CREATE TABLE spat_idx_test_result(
[perm_id] [int] NOT NULL,
[num_cells] [int] NOT NULL,
[permut] [nvarchar](4) NOT NULL,
[g1t1] [bigint] NULL,
[g1t2] [bigint] NULL,
[g1t3] [bigint] NULL,
[g1t4] [bigint] NULL,
[g2t1] [bigint] NULL,
[g2t2] [bigint] NULL,
[g2t3] [bigint] NULL,
[g2t4] [bigint] NULL
)
INSERT INTO dbo.spat_idx_test_result
VALUES (0,16,0,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL)
END
/* delete all rows from "spat_idx_test_result" table. This makes it ready to stuff in new results.
!!!WARNING!!! if your test was interupted, the table will be cleared out and the test will
begin from the beginning. You could try to modify this to start where you left off but
I didn't have time and this worked well enough for me. */
DELETE FROM spat_idx_test_result
WHERE perm_id != 0
/* set up counters */
DECLARE @a1 INT
DECLARE @a2 INT
DECLARE @a3 INT
DECLARE @a4 INT
/* set up variables to hold high/medium/low values and permutation to use in rebuilding
the spatial index and recording stats */
DECLARE @lev1 VARCHAR(6)
DECLARE @lev2 VARCHAR(6)
DECLARE @lev3 VARCHAR(6)
DECLARE @lev4 VARCHAR(6)
DECLARE @permut VARCHAR(6)
DECLARE @num_cell VARCHAR(4)
DECLARE @time_str VARCHAR(20)
DECLARE @perm_id VARCHAR(20)
/* create variables to hold timestamps for beginning and ending of test queries */
DECLARE @start_t DATETIME
DECLARE @end_t DATETIME
DECLARE @elapse_t INT
/* begin looping through cell option permutations */
SET @a1 = @min_cells_per_obj
WHILE @a1 <= @max_cells_per_obj
BEGIN
SET @a2 = 1
PRINT 'Started Testing for ' +CAST(@a1 AS VARCHAR(10)) +' cells per object'
WHILE @a2 < 82
BEGIN
SELECT @lev1 = level1, @lev2 = level2, @lev3 = level3, @lev4 = level4 FROM cell_opt_perm WHERE perm_id = @a2
SET @permut = '''' +(SELECT permutation FROM cell_opt_perm WHERE perm_id = @a2) +''''
EXEC
('
CREATE SPATIAL INDEX ' +@idxnm +' ON ' +@tabnm +'
(
[geom]
)
USING GEOMETRY_GRID
WITH
(
BOUNDING_BOX =(-100, -100, 300000, 650000),
GRIDS =(LEVEL_1 = ' +@lev1 +' ,LEVEL_2 = ' +@lev2 +' ,LEVEL_3 = ' +@lev3 +' ,LEVEL_4 = ' +@lev4 +' ),
CELLS_PER_OBJECT = ' +@a1 +' ,
PAD_INDEX = OFF,
SORT_IN_TEMPDB = OFF,
DROP_EXISTING = ON,
ALLOW_ROW_LOCKS = ON,
ALLOW_PAGE_LOCKS = ON,
FILLFACTOR = 100
)
ON [PRIMARY]'
)
PRINT 'Re-built index to ' +@permut
SET @a3 = 1
SET @a4 = 1
WHILE @a3 < 5
BEGIN
SET @start_t = GETDATE()
EXEC
(
'CREATE TABLE #tmp_tab (shp GEOMETRY)
DECLARE @g1 GEOMETRY
SET @g1 = ' +@testgeom1 +'
INSERT #tmp_tab (shp)
SELECT
r.geom AS shp
FROM
' +@tabnm +' r
WHERE
r.geom.STIntersects(@g1) = 1
DROP TABLE #tmp_tab'
)
SET @end_t = GETDATE()
SET @elapse_t = (SELECT DATEDIFF(MS, @start_t, @end_t))
SET @num_cell = CAST(@a1 AS VARCHAR(6))
SET @time_str = CAST(@elapse_t AS VARCHAR(20))
IF @a3 = 1
BEGIN
IF (SELECT TOP 1 perm_id FROM spat_idx_test_result) IS NULL
BEGIN
SET @perm_id = 1
END
ELSE
BEGIN
SET @perm_id = CAST((SELECT MAX(perm_id+1) FROM spat_idx_test_result) AS VARCHAR(20))
END
EXEC
(
'INSERT INTO spat_idx_test_result (perm_id, num_cells, permut, g1t' +@a3 +')
VALUES (' +@perm_id +', ' +@num_cell +', ' +@permut +', ' +@time_str +')'
)
END
ELSE
EXEC
(
'UPDATE spat_idx_test_result
SET
num_cells = ' +@num_cell +',
permut = ' +@permut +',
g1t' +@a3 +' = ' +@time_str +'
WHERE perm_id = ' +@perm_id
)
SET @a3 = @a3 + 1
END
WHILE @a4 < 5
BEGIN
SET @start_t = GETDATE()
EXEC
(
'CREATE TABLE #tmp_tab (shp GEOMETRY)
DECLARE @g2 GEOMETRY
SET @g2 = ' +@testgeom2 +'
INSERT #tmp_tab (shp)
SELECT
r.geom AS shp
FROM
' +@tabnm +' r
WHERE
r.geom.STIntersects(@g2) = 1
DROP TABLE #tmp_tab'
)
SET @end_t = GETDATE()
SET @elapse_t = (SELECT DATEDIFF(MS, @start_t, @end_t))
SET @num_cell = CAST(@a1 AS VARCHAR(6))
SET @time_str = CAST(@elapse_t AS VARCHAR(20))
EXEC
(
'UPDATE spat_idx_test_result
SET
num_cells = ' +@num_cell +',
permut = ' +@permut +',
g2t' +@a4 +' = ' +@time_str +'
WHERE perm_id = ' +@perm_id
)
SET @a4 = @a4 + 1
END
SET @a2 = @a2 + 1
END
SET @a1 = @a1 + 1
END
PRINT 'Testing of ' +@tabnm +' spatial index: ' +@idxnm +' is complete!'
