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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004
3.3.2 Oracle Database Physical Design: Oracle database
physical design is a file distribution plan on different
equipments. In order to accomplish physical design we must
tell the I/O contention of data files, the I/O bottleneck of
database files, the concurrent I/O process of the background
process and the disk used for database. Define the safety and
performance goal of the database, system hardware
environment and image structure.
In this spatial database we give a reference of four disks
physical design, Table 1. Its rationality has not been ensured.
Disk Contents
1 The Tablespace Files of SYSTEM, SDE and
TEMP, Control File, Redo Log File
2 The Tablespace Files of INDEXS and RBS,
Control File, Redo Log File, Export Files
3 The Tablespace Files of DOM, DEM, DRG,
DLG, METADATA and TOOLS, Control File,
Redo Log File
4 Oracle Software Files, ArcSDE Software Files,
Archive Log File, RASDERIVE Tablespace
Files.
Table 1. Four disks physical design
4. SPATIAL DATABASE CONFIGURATION AND
T UNING
4.1 Table Object Configuration
Once the size of oracle data block, a basic unit on database
operation, is determined, it can't be changed until recreate a
new database. So it is important to define the size properly. As
mentioned above, Raster Block Table needs a large disk space.
In this table the spatial data is stored as long raw or blob data
type. Large row size and rows accessed sequently need a large
data block size. However the Business Table, Raster Band
Table, Raster Band Auxiliary Table need few disk. Too large
data block size will make inverse effect. The ARCSDE suggest
that the least block is 8KB and the block size of 16KB has
more efficient for polyline and polygon features. So here we
use the 16KB data block size.
4.1.1 Table Object of The Raster Dataset
4.1.1.1 Small Table Objects: The small table objects such as
Business Table, Raster Table, Raster Band Table and Raster
Band Auxiliary Table only need one data block. So the storage
parameter in the dbtune.sde file of ARCSDE is configured as
following.
B STORAGE "PCTFREE 10 PCTUSED 90 INITRANS 4
TABLESPACE RASTERDERIVE STORAGE (INITIAL 16K
NEXT 16K FREELISTS 4 MINEXTENTS 1 PCTINCREASE
0)"
RAS STORAGE . "PCTFREE 10 PCTUSED 90
INITRANS 4 TABLESPACE RASTERDERIVE STORAGE
(INITIAL 16K NEXT 16K MINEXTENTS 1 MAXEXTENTS
200 PCTINCREASE 0 FREELISTS 4)"
BND_STORAGE "PCTFREE 10 PCTUSED 90
INITRANS 4 TABLESPACE RASTERDERIVE STORAGE
(INITIAL 16K NEXT 16K MINEXTENTS 1 MAXEXTENTS
200 PCTINCREASE 0 FREELISTS 4)"
AUX STORAGE "PCTFREE 10 PCTUSED 90
INITRANS 4 TABLESPACE RASTERDERIVE STORAGE
(INITIAL 16K NEXT 16K MINEXTENTS 1 MAXEXTENTS
200 PCTINCREASE 0 FREELISTS 4)"
4.1.1.2 Large Table Objects: The large table objects such as
Raster Block Table need a great amount of data blocks. The
amount of data blocks depends on the character of source data
and the compress method used. And another factor is the user-
defined dimension of the raster block in ArcSDE. We make an
experiment such as table 2 and table 3.
Block Table SDE BL | SDE BL | SDE BI. | SDE Bi
Name K 38 K 23 K 24 K 27
Raster Block 32*32 64*64 128*128 | 256*256
Dimension
Avg. Row Size 2252 9041 33759 133469
Number of 520778 130671 32889 8331
Rows
Number of 0 0 30368 8187
Chaining Rows
Number of 87699 130671 86744 72889
Data Block of
Table
Number of 952 | --——— 72 24
Data Block of
Index
Table 2. The Experiment of the Raster Block Table
Block Table The Ratio of Number of Disk Space
Name Efficient Data Block
Disk Space Per Row
SDE BLK 38 81.6% 0.17 1.34G
SDE_BLK 23 60.5% 0.87 1.73G
SDE_BLK_24 78% 2.63 1.32G
SDE_BLK_27 | 93% 8.75 1.12G
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