ISPRS Workshop on Service and Application of Spatial Data infrastructure, XXXVI(4/W6), Oct.14-16, Hangzhou, China 
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2.2 Different Description of the Spatial Features 
Different GIS software uses the different methods for 
describing the spatial features stored in Oracle, for example, 
Maplnfo uses two dimensional coordinates (xl, yl, x2, y2 ) 
and coding for objects ( point:2001, line:2002, area:2003 etc); 
while AutoDesk Map uses three dimensional coordinates (xl, 
yl * zlt ^2, y2, z2 ) and coding for objects (point: 3001, 
line:3002, area:3003 etc). It is understood that these data of 
coordinates and coding are all stored into the databases of their 
own, however, the different GIS software adopted the different 
rules, and the rules could not be read each other 
As things are at the moment, there are three models that may be 
selected to solve the problems as mentioned above. One of the 
models is based on the different software platform, its main 
objective is to adopt common agreement when describing the 
spatial object, this model is rather limited. The second one is to 
work on the object metadata, and the metadata will be further 
developed based on the knowledge we have got to realize the 
interoperability. This one will be the emphasis discussed in this 
paper. The third one is called middleware model, that can be 
used to develop an interoperation method between Oracle and 
application system, unfortunately there is no ready middleware 
so far. 
3. METHOD TO EDIT THE ORACLE METADATA 
The central point of this method is to edit the metadata 
according to the requirements of interoperability by analyzing 
the differences of the info and structure of metadata in different 
GIS system. 
Let us take Maplnfo and Map as an example to explain that how 
they edit the metadata and can directly access the same spatial 
data in Oracle Spatial. 
3.1 Maplnfo Read the Spatial Data in Oracle Spatial Stored 
by Map 
First explain the method that Maplnfo stored data in Oracle 
Spatial, then discuss how Maplnfo read the data saved by Map. 
When uploading data to Oracle using its own user model, 
Maplnfo first register the metadata in Maplnftyjnapcatalog 
according to the basic info of the TAB, then load the object 
feature data to the table circularly. Meanwhile add some 
attribute field in the related table that is necessary when 
Maplnfo read the data. 
Comparing the table in Maplnfo and the table upload to 
database, three fields have been added 
GEOLOC field to store coordinates 
MI_PRINX primary key of the data table 
MI_STYLE symbol field to store objects symbol info 
Meanwhile, a spatial index was established in the field 
GEOLOC, an unique index has been established in MIPRINX. 
The names of the spatial data field and the unique index field 
are allowed to be changed, Maplnfo only requires the 
consistency of the registered field name in metadata table and 
field name in data table. This change of the field name provides 
the possibility for Maplnfo to read the data saved by other GIS 
software. 
The process for Maplnfo to read the spatial data that Map stored 
in Oracle Spatial: 
(1) Add MI STYLE field in data table, with the content null. 
(2) Register the data table in Maplnfojnapcatalog. 
Add the name of the field that store the spatial data in data table 
in SPATIALCOLUM, add MI PRINX in SYMBOL, and fill in 
the other corresponding field info. 
After these procedures, Maplnfo can read the spatial data stored 
by Map via DBMS data engine. 
3.2 Map Access the Spatial Data in Oracle Spatial Stored by 
Maplnfo 
First explain how Map stores the data in Oracle Spatial, then 
discuss how Map can read the spatial data saved in Oracle 
Spatial by Maplnfo. 
It is quite similar to Maplnfo when Map upload data to Oracle. 
First register in the metadata table, Map has several metadata 
tables in database. 
Admpfeaturelayer: record the relation between data table in 
database and the layer in Map, one table in Oracle can relate to 
one or more layer in Map, but one layer can only relate to one 
table. 
Admpimportsettings: record whether the user has set lock to 
Oracle schema. 
Admpmetadata: record how Map interpret the fields of the 
table in the database, 
Admpoptions: initial status is null, to save the settings for 
some query information, 
Admposemetadata: record projection and boundary info of the 
data table» 
For spatial data table, unlike the OBJECTDATA in DWG 
format, add fields in table structure: 
GEOMETRY: Field to save coordinates 
ENTITYID: Primary Key of the data table 
MAP: Symbol attribute field that Map used to explain object 
symbol 
In a word, the process for Map to read the data saved by 
Maplnfo is as follows: first add fields in the data table for 
symbol and layer name etc, and then add corresponding 
contents. When the table structure and contents are adjusted, 
next step is to register the data table in above metadata table 
belong Map schema, and then Map can access the table stored 
by Maplnfo. 
It may be seen from above analysis that if we want to access the 
data stored by Maplnfo in Oracle Spatial using AutoDesk Map, 
we have to built the register info of spatial data table of 
Maplnfo in AutoDesk Map metadata table according to the 
rules and semanteme, by which Map interprets the spatial data 
table, and add some symbol info for Map in data table. Also, if 
we want to access the data stored by Map in Oracle Spatial 
using Maplnfo, we have to built the register info of spatial data 
table of Map in Maplnfo metadata table according to the rules 
and semanteme, by which Maplnfo can interpret spatial data 
table, and add some symbol info for Maplnfo in data table. That