Max # extents exceeded

Question

Hi,
I am having problems with the max # extents being exceeded.
I am creating a spatial index using the following script:
CREATE INDEX GIS.MYTABLE_SX ON
GIS.MYTABLE(GEOMETRY)
indextype is MDSYS.SPATIAL_INDEX
parameters ( 'SDO_LEVEL=6,
     SDO_NUMTILES = 8,
     SDO_COMMIT_INTERVAL = 1000,
     TABLESPACE = GISI,
     INITIAL = 131072,
     NEXT = 131072,
     PCTINCREASE = 0,
     MINEXTENTS = 1,
     MAXEXTENTS = 2147483645,
     BTREE_INITIAL = 512K,
     BTREE_NEXT = 512K,
     BTREE_PCTINCREASE = 0')
This in turn creates the table
MYTABLE_SX_HL6N8$
and
the indexes
MYTABLE_SX_HL6N8$_B1
(x4 - one for each field SDO_GROUPCODE, SDO_CODE, SDO_STATUS, SDO_ROWID)
and
MYTABLE_SX_HL6N8$_B2
(x1 one for SDO_ROWID)
using the following script:
DROP TABLE MYTABLE_SX_HL6N8$ CASCADE CONSTRAINTS ;
CREATE TABLE MYTABLE_SX_HL6N8$ (
SDO_GROUPCODE RAW (14),
SDO_ROWID ROWID,
SDO_CODE RAW (14),
SDO_STATUS VARCHAR2 (1))
TABLESPACE GISI
PCTFREE 10
PCTUSED 40
INITRANS 1
MAXTRANS 255
STORAGE (
INITIAL 131072
NEXT 131072
PCTINCREASE 0
MINEXTENTS 1
MAXEXTENTS 2147483645
FREELISTS 1 FREELIST GROUPS 1 )
NOCACHE;
CREATE INDEX MYTABLE_SX_HL6N8$_B1 ON
"GIS".MYTABLE_SX_HL6N8$(SDO_GROUPCODE, SDO_CODE, SDO_ROWID, SDO_STATUS)
TABLESPACE GISI PCTFREE 10 STORAGE(INITIAL 524288 NEXT 524288 PCTINCREASE 0 )
CREATE INDEX MYTABLE_SX_HL6N8$_B2 ON
"GIS".MYTABLE_SX_HL6N8$(SDO_ROWID)
TABLESPACE GISI PCTFREE 10 STORAGE(INITIAL 524288 NEXT 524288 PCTINCREASE 0 )
The problem is when you create a spatial index using the top script the max # extents do not get applied to
MYTABLE_SX_HL6N8$_B1
and
MYTABLE_SX_HL6N8$_B2
Instead these tables take on the default max # extents set on the tablespace.
How do I set the max # extents for indexes
MYTABLE_SX_HL6N8$_B1
and
MYTABLE_SX_HL6N8$_B2
to MAXEXTENTS 2147483645 for example. I am aware that this is not good practice but I would like to know if it is possible. Is it a spatial issue? I have tried to increase the size of
the BTREE_INITIAL and BTREE_NEXT to 512K from 128K but it still complains about max # extents (999) reached. A way round it is obviously to increase the default max # extents on the tablespace but that requires DBA intervention. I would like to know how one can do this programatically using the top script or something similar.
Thanks
Regards
Stephen

Answer 1

Hi Stephen,
A few thoughts:
Oracle has pretty much dropped hybrid indexing in terms of it being
a generically useful way to index data. As of 9.0.1.2 the suggestion
is to use R-tree indexes unless there is something about your
workload or data set that makes the use of R-trees bad.
If you don't use R-tree indexing, then stick with fixed indexing. The
original idea of hybrid indexing was to allow better approximations
of geometries without the index growing too large, but it turns out the
SQL index query within spatial took longer than anticipated.
In terms of setting up the spatial index, when creating a quadtree index
you can specify the btree_initial and btree_next in the parameters clause
of the create index statement, which allows you to adjust the btree indexing
parameters as you noted, but there is no way to set the max number of
extents (or in fact the tablespace used for the b-tree indexes).
When you need that control, you need to to have dba intervention to set the
default tablespace and parameters at the user level before creating the spatial
index. The parameters in the parameters clause can set up the index table
parameters, and the default parameters can be used for the btree indexes.
regards,
dan