空间数据库课件：第四讲 Oracle 及Oracle Spatial

1、第四讲 Oracle 及Oracle SpatialOracle简介Oracle公司是全球最大的信息管理软件及服务供应商，也是全球第二大独立软件公司，成立于1977年，总部位于美国加州Redwoodshore，Oracle是世界上第一个商品化的关系型数据库管理系统，也是第一个在其全线产品中开发并部署100%基于互联网企业软件的公司，为世界上150个以上的国家提供数据库、服务器、开发工具和企业应用产品，还有相关的咨询、教育和支持服务。Evolution of Oracle SQL EngineOracle81997Oracle8i1999Oracle9i2001Oracle9i R22002SQ

2、L /XML Integration (XMLType, URIType, etc.) OLAPDatetime TypesANSI JoinsCASE ExpressionsXML DBSQL/XMLW3C StandardsData MiningGridWeb ServicesRegular ExpressionsNative NumbersBLASTExpression FilterObjects ExtensionData Cartridges SQL/Java IntegrationinterMedia TypesData and Processing complexityOracl

3、e 10g2003二、ORACLE体系结构总览DatabaseInstanceSGARedo logbufferData buffercacheShared poolData dict.cacheLibrarycache PMON DBW0SMON LGWRCKPTOthersUserprocessServerprocessPGAControl filesData files Redo logfilesArchived log filesParameterfilePasswordfileFixed SGAORACLE体系结构总览OracleRedo Log BufferData BufferS

4、hared Pool后台进程：SGA内存DatabaseInstance表空间段区块数据库文件控制文件日志文件三个辅助文件：参数文件、口令文件，归档文件三个核心文件物理存储逻辑存储Oracle数据库对象User Process and Server ProcessOracle-DBMSPMON, SMON, DBWR, LGWR,（1）支持大数据库、多用户的高性能的事务处理。（2）Oracle遵守数据存取语言、操作系统、用户接口和网络通信协议的工业标准。（3）实施安全性控制和完整性控制。（4）支持分布式数据库和分布处理。（5）具有可移植性、可兼容性和可连接性。（6）支持UDT，其Spatial

5、广泛用于GIS数据的存储 Oracle特征RasterTopologyNetwork modellingSpatial MiningMapViewerOracle 7.3.3Spatial Data OptionPoints, Lines, PolygonsSpatial OperatorsOracle 8.0.4Spatial CartridgePoints, Lines, PolygonsSpatial Operators40% Faster PerformanceOracle 8iSpatial Data TypeSpatial OperatorsLinear ReferencingCo

6、ordinate TransformationLong transactions .1994 1995 1996 1997 1998 1999 2000 2001 2003 2004 2005 2007Replication, partitioningSpatial aggregationGeodetic coordinates Oracle 9i Oracle 10g Oracle 7.1.6Multi DimensionPoints OnlyOracle 11g 3D supportSolid modellingWeb servicesOracle对空间数据的支持Oracle对空间数据的支

7、持OGCWMS, WFS, GML, WFS-T, CS-W, KML, CityGML geometrytopologynetworksgeoraster3D modelsMapInfoIntergraphMapViewerESRIBentleyAutodeskOracle Spatial组成： 一个MDSYS Schema（模式），规定了对空间数据类型在存储、语法、语义方面的支持； 一种空间索引机制（R-Tree,四叉树）； 一组操作过程和函数来执行空间查询和相关空间分析操作（服务器端空间操作算子）； 相关管理工具。Oracle Spatial强大的线性参照系统 400 多个空间运算函数，

8、如质心和聚合函数GeoRaster 数据类型，支持地理参照栅格图像的原生功能 支持更多文件格式以便加载和导出，支持更多的元数据和数据类型 存储和分析网络（图形）结构的数据模型 ，针对大型空间网络的按需加载，增强的高级分析和建模特性可持续存储和更新的拓扑的数据模型和模式 空间分析函数 支持地形模型、城市模型和虚拟世界的 3维数据类型，以及Lidar/PointCloud数据的支持Web服务支持（WFS 1.0/WFS-T 1.0/CSW 2.0/OpenLS 1.1/web服务安全性）支持SQL/MM 空间类型和操作符空间Java API 空间数据模型Oracle Spatial 在 MDSYS

9、 模式下定义了一系列几何类型、函数来支持空间数据的存储和使用，最为核心的是SDO_GEOMETRY 类型ArcSDE 也可以使用该类型。CREATE TYPE sdo_geometry AS OBJECT (SDO_GTYPE NUMBER,SDO_SRID NUMBER,SDO_POINT SDO_POINT_TYPE,SDO_ELEM_INFO MDSYS.SDO_ELEM_INFO_ARRAY,SDO_ORDINATES MDSYS.SDO_ORDINATE_ARRAY);（1）SDO_GTYPESDO_GTYPE是一个NUMBER型的数值，用来定义存储对象的类型。SDO_GTYPE是一

10、个4个数字的整数，其格式为dltt，其中d表示几何对象的维数；l表示三维线性参考系统中的线性参考值，当d为3维或者4维时需要设置该值，一般情况下为空；tt为几何对象的类型，Oracle Spatial定义了9种类型的几何类型，目前，tt使用了00到09另外，10到99是Oracle Spatial保留的数字，以备将来几何对象扩展所用。 （2）SDO_SRIDSDO_SRID也是一个NUMBER型的数值，它用于标识与几何对象相关的空间坐标参考系。如果SDO_SRID为空（null），则表示没有坐标系与该几何对象相关；如果该值不为空，则该值必须为MDSYS.CS_SRS表中SRID字段的一个值，在

11、创建含有几何对象的表时，这个值必须加入到描述空间数据表元数据的USER_SDO_GEOM_METADATA视图的SRID字段中。Oracle Spatial规定，一个几何字段中的所有几何对象都必须为相同的SDO_SRID值。 （3）SDO_POINTSDO_POINT是一个包含X,Y,Z数值信息的对象，用于表示几何类型为点的几何对象。如果SDO_ELEM_INFO和SDO_ORDINATES数组都为空，则SDO_POINT中的X,Y,Z为点对象的坐标值，否则，SDO_POINT的值可以忽略（用NULL表示）。Oracle Spatial强烈建议用SDO_POINT存储空间实体为点类型空间数据，

12、这样可以极大的优化Oracle Spatial的存储性能，提高查询效率。 （3）SDO_POINTSDO_POINT是一个包含X,Y,Z数值信息的对象，用于表示几何类型为点的几何对象。如果SDO_ELEM_INFO和SDO_ORDINATES数组都为空，则SDO_POINT中的X,Y,Z为点对象的坐标值，否则，SDO_POINT的值可以忽略（用NULL表示）。Oracle Spatial强烈建议用SDO_POINT存储空间实体为点类型空间数据，可以极大的优化Oracle Spatial的存储性能，提高查询效率。 10000个点（4）SDO_ELEM_INFOSDO_ELEM_INFO是一个可变

13、长度的数组，每3个数作为一个元素单位，用于解释坐标是如何存储在SDO_ORDINATES数组中的。这里把组成一个元素的3个数称为3元组。一个3元组包含以下3部分的内容：l SDO_STARTING_OFFSETSDO_STARTING_OFFSET 表明每个几何元素的第一个坐标在SDO_ORDINATES数组中的存储位置。它的值从1开始，逐渐增加。 lSDO_ETYPE SDO_ETYPE 用于表示几何对象中每个组成元素的几何类型。当它的值为1, 2, 1003和2003时，表明这个几何元素为简单元素。如果SDO_ETYPE为1003，表明该多边形为外环（第一个数为1表示外环），坐标值以逆时针

14、存储；如果SDO_ETYPE为2003，表明该多边形为内环（第一个数为2表示内环），坐标值以顺时针存储。当SDO_ETYPE为4, 1005和2005时，表明这个几何元素为复杂元素。它至少包含一个3元组用以说明该复杂元素具有多少个简单几何元素。同样，1005表示多边形为外环，坐标值以逆时针存储；2005表示多边形为内环，坐标值以顺时针存储。l SDO_INTERPRETATION SDO_INTERPRETATION具有两层含义，具体的作用由SDO_ETYPE是否为复杂元素决定。如果SDO_ETYPE是复杂元素（4, 1005和2005），则SDO_INTERPRETATION表示它后面有几个

15、子3元组属于这个复杂元素。如果SDO_ETYPE是简单元素（1, 2, 1003和2003），则SDO_INTERPRETATION表示该元素的坐标值在SDO_ORDINATES中是如何排列的。（5）SDO_ORDINATESSDO_ORDINATES是一个可变长度的数组，用于存储几何对象的真实坐标，该数组的类型为NUMBER型，它的最大长度为1048576。SDO_ORDINATES必须与SDO_ELEM_INFO数组配合使用，才具有实际意义。SDO_ORDINATES的坐标存储方式由几何对象的维数决定，如果几何对象为三维，则SDO_ORDINATES的坐标以X1,Y1,Z1,X2,Y2,Z

16、2,.的顺序排列，如果几何对象为二维，则SDO_ORDINATES的坐标以X1,Y1,X2,Y2,.顺序排列。 SDO_Geometryinsert into BJPIC.GEOD_COUNTRY values(20,MDSYS.SDO_GEOMETRY(2007,NULL,NULL,MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,1,53,1003,1),MDSYS.SDO_ORDINATE_ARRAY(109.633316,18.113594,109.142250,18.347574,108.855591,18.499420,108.764137,19.077269,10

17、8.780563,19.204344,108.888641,19.312555,109.077347,19.420931,109.401825,19.701113,109.623779,19.676178,109.645920,19.752447,109.753990,19.930529,109.861320,19.918058,110.119545,。含有一个孔的多边形的存储SDO_GTYPE = 2003.2 表示是2维的，3 表示是一个多边形。SDO_SRID = NULL.SDO_POINT = NULL.SDO_ELEM_INFO = (1,1003,1, 19,2003,1). 此

18、处有两个三个一组的元素:1,1003,1 和 19,2003,1。1003 表示元素是一个外多边形环；2003表示元素是一个内多边形环。19 表示第二个元素（内多边形环）的坐标从SDO_ORDINATES数组的第19个数字开始 (也就是说7，意思是第一个点的坐标为 7,5)。INSERT INTO cola_markets VALUES(10,polygon_with_hole,MDSYS.SDO_GEOMETRY(2003, - 2-dimensional polygonNULL,NULL,MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,1, 19,2003,1), MDS

19、YS.SDO_ORDINATE_ARRAY(2,4, 4,3, 10,3, 13,5, 13,9, 11,13, 5,13, 2,11, 2,4,7,5, 7,10, 10,10, 10,5, 7,5);含有一个孔的多边形的存储复杂对象的存储第一组数字表示这个元素是一个复合多边形，它由两个曲线子元素组成，下两组数字描述了这两个子元素。第二组数字表示第一个曲线子元素由直线段组成，坐标起始点为1，结束点为第二条曲线的起始点5。因为是二维的，第一条曲线的结束点坐标在5和6。第三组数字表示第二个曲线子元素由一个圆弧组成，坐标起始点为5，结束点为下一条曲线的起始点或SDO_ORDINATES数组的当前长

20、度（如果是最后一个元素）。集合类型的存储MultipointSDO_GEOMETRY(2005, 32774, NULL,SDO_ELEM_INFO_ARRAY - multiple elements each with 1 pt(1,1,1, - triplet for first point element3,1,1, - triplet for second point element5,1,1 - triplet for third point element),SDO_ORDINATE_ARRAY(Xa, Ya, - coordinates of first pointXb, Yb,

21、 - coordinates of second pointXc, Yc - coordinates of third point)集合类型的存储MultipointSDO_GEOMETRY(2005, 32774, NULL,SDO_ELEM_INFO_ARRAY - SDO_ELEM_INFO attribute(1, 1, 3 - Point cluster element with 3 points),SDO_ORDINATE_ARRAY(Xa, Ya, - coordinates of first pointXb, Yb, - coordinates of second pointX

22、c, Yc - coordinates of third point)推荐方式集合类型的存储Multiline集合类型的存储SELECT SDO_UTIL.APPEND(SDO_GEOMETRY(2003, 32774, null,SDO_ELEM_INFO_ARRAY(1,1003, 3),SDO_ORDINATE_ARRAY(1,1, 2,2),SDO_GEOMETRY(2003, 32774, NULL,SDO_ELEM_INFO_ARRAY(1, 1003, 3),SDO_ORDINATE_ARRAY(2,3, 4,5) FROM dual;SDO_UTIL.APPEND(SDO_GE

23、OMETRY(2003,32774,NULL,.-SDO_GEOMETRY(2007, - SDO_GTYPE= Multi-polygon32774, NULL,SDO_ELEM_INFO_ARRAY(1, 1003, 3, 5, 1003, 3),SDO_ORDINATE_ARRAY(1, 1, 2, 2, 2, 3, 4, 5)三维数据的存储INSERT INTO geometry_examples (name, description, geom) VALUES(3-D POINT,3d Point , SDO_GEOMETRY (3001, - SDO_GTYPE format: D

24、00T. Set to 3001 for a 3-dimensional pointNULL, - No coordinate systemSDO_POINT_TYPE(2, - ordinate value for first dimension0 - ordinate value for second dimension2 - ordinate value for third dimension),NULL, - SDO_ELEM_INFO is not needed as SDO_POINT field is populatedNULL - SDO_ORDINATES is not ne

25、eded as SDO_POINT field is populated);三维点数据的存储INSERT INTO geometry_examples (name, description, geom) VALUES(3-D LineString,3-dimensional LineString ,SDO_GEOMETRY(3002, - SDO_GTYPE format: D00T. Set to 3002 for a 3-dimensional lineNULL, - No coordinate systemNULL, - No data in SDO_POINT attributeSDO

26、_ELEM_INFO_ARRAY( 1, 2, 1),SDO_ORDINATES_ARRAY(2, - first dimension for first point0, - second dimension for first point2, - third dimension for first point4, - first dimension for second point2, - second dimension for second point4 - third dimension for second point);三维线数据的存储ST_GeometryOracle也提供了另外

27、一种类型 ST_GEOMETRY，同时在此基础上提供了一些符合 OGC Simple Features Access 规范的操作。 事实上还是通过对SDO_GEOMETRY 的包装实现的。SQL select st_point(1,1) from dual; ST_POINT(1,1)(GEOM(SDO_GTYPE, SDO_SRID, SDO_POINT(X, Y, Z), SDO_ELEM_INFO, SDO_ORDINATES) - ST_POINT(SDO_GEOMETRY(2001, NULL, SDO_POINT_TYPE(1, 1, NULL), NULL, NULL) 几何对象

28、的构造空间数据的装载与转换Inserting Data into an SDO_GEOMETRY ColumnLoading from Text Files Using SQL*LoaderLOAD DATA INFILE *INTO TABLE sales_regionsAPPENDFIELDS TERMINATED BY |TRAILING NULLCOLS(id NULLIF ID = BLANKS,geom COLUMN OBJECT(SDO_GTYPE INTEGER EXTERNAL,SDO_POINT COLUMN OBJECT(X FLOAT EXTERNAL,Y FLOAT

29、EXTERNAL)BEGINDATA1|2001|-76.99022|38.888654|2|2001|-77.41575|38.924753|SQLLDR spatial/spatial CONTROL=sales_regions.ctl空间数据的装载与转换Transporting Spatial Data Between Oracle DatabasesImport/Export UtilitiesEXP spatial/spatial FILE=customers.dmp TABLES=customersIMP scott/tiger FILE=customers.dmp IGNORE=

30、Y INDEXES=N TABLES=CUSTOMERSLoading from External FormatsSHP2SDO customers -g location -x(-180,180) -y(-90,90) -s 8307 -t 0.5The SHP2SDOutility outputs three files:customers.sql；customers.ctl；customers.dat.SQLPLUS spatial/spatial customers.sqlSQLLDR spatial/spatial CONTROL=customers.ctl空间数据的装载与转换Con

31、verting Between SDO_GEOMETRY and WKT/WKBSELECT a.location.GET_WKT() wkt FROM customers a WHERE id=1;SELECT SDO_UTIL.TO_WKTGEOMETRY(a.location) wkt FROM customers a WHERE id=1; Converting SDO_GEOMETRY Data in GML SELECT TO_CHAR(SDO_UTIL.TO_GMLGEOMETRY(location) gml_location FROM customers WHERE id=1;

32、 -GML2.0SELECT TO_CHAR(SDO_UTIL.TO_GML311GEOMETRY(）；-3.1Converting GML to SDO_GEOMETRYSELECT SDO_UTIL.FROM_GML311GEOMETRY(TO_CLOB()；空间索引Oracle支持R树索引以及四叉树索引create index idx_test_index_geom on spatial.test_index(geom) indextype is mdsys.spatial_index;需首先在视图USER_SDO_GEOM_METADATA插入表元数据insert into mdsys

33、.user_sdo_geom_metadata(table_name,column_name,diminfo) values(TEST_INDEX,GEOM, SDO_DIM_ARRAY( SDO_DIM_ELEMENT(X,1,100000,1), SDO_DIM_ELEMENT(Y,1,100000,1);create index idx_continent_geom on spatial.continent(geom) indextype is mdsys.spatial_index parameters(SDO_LEVEL=8);空间运算Oracle支持多种空间算子 SDO_RELAT

34、E 操作比较特殊，它通过 mask 参数来判断几何对象间是否满足某种空间关系空间运算Oracle支持多种空间算子 select continent from continent where sdo_inside(geom, SDO_GEOMETRY(2003,NULL,NULL,SDO_ELEM_INFO_ARRAY(1,1003,1),SDO_ORDINATE_ARRAY(0,0,180,-90,180,90,0,0)=TRUE; select continent from continent where sdo_relate(geom, SDO_GEOMETRY(2003,NULL,NUL

35、L,SDO_ELEM_INFO_ARRAY(1,1003,1),SDO_ORDINATE_ARRAY(0,0,180,-90,180,90,0,0), mask=INSIDE)=TRUE; 空间运算Oracle支持多种空间算子 缓冲分析select sdo_geom.sdo_buffer(SDO_GEOMETRY(2001,4326,SDO_POINT_TYPE(0,0, NULL),NULL,NULL),1000,1,arc_tolerance=0.1 unit=km) from dual;距离量测select objectid,sdo_geom.sdo_distance(SDO_GEOME

36、TRY(2001,NULL,SDO_POINT_TYPE(0,0, NULL),NULL,NULL),shape,0.01) from sdo_cities where objectid desc sdo_georaster Name Type - - RASTERTYPE NUMBER SPATIALEXTENT SDO_GEOMETRY RASTERDATATABLE VARCHAR2(32) RASTERID NUMBER METADATA SYS.XMLTYPEThe SDO_GEORASTER object type is included when Oracle Spatial i

37、s installed.The SDO_GEORASTER object type has five attributesThe pair (RASTERID, RASTERDATATABLE) uniquely identify a raster object in the database for specific user Various user-defined columnsSDO_GEORASTER object(for example, Boston)For eachrow (image):SDO_GEORASTER Object Type RASTERTYPE A five-d

38、igit number in the format d b t gt where: d identifies the number of spatial dimensions Currently must be 2 b indicates band or layer information 0 means one band or layer, 1 means more than one band or layer t must be set to 0, and is reserved for future use gt is the two-digit GeoRaster type, and

39、currently must be set to 01A RASTERTYPE of 20001 is raster data that has two dimensions and one band, and 21001 is raster data that has two spatial dimensions and one or more bandsSDO_GEORASTER Object Type SPATIALEXTENT defines the spatial extent or footprint associated with the raster data. The SPA

40、TIALEXTENT is of type SDO_GEOMETRY and its coordinate system is the model coordinate system if the raster data is georeferenced, or NULL if the raster data is not georeferenced.RASTERDATATABLE identifies the name of the raster data table. The raster data table contains the GeoRaster data, and has on

41、e row for each stored raster block. This table is created and managed by Oracle Spatial GeoRaster.RASTERID is used together with RASTERDATATABLE to uniquely identify all of the data associated with a GeoRaster object. METADATA is the XML metadata defined by Oracle Spatial GeoRaster SDO_RASTER Object

42、 TypeSQL desc sdo_raster Name Type - -RASTERID NUMBERPYRAMIDLEVEL NUMBERBANDBLOCKNUMBER NUMBERROWBLOCKNUMBER NUMBERCOLUMNBLOCKNUMBER NUMBERBLOCKMBR SDO_GEOMETRYRASTERBLOCK BLOBThe SDO_RASTER object type is included when Oracle Spatial is installed.SDO_RASTER Object Type RASTERID associates one or mo

43、re blocks of raster data in the raster data table with a specific row in a table containing the SDO_GEORASTER object type. Each block in the raster data table is stored in a separate row.PYRAMIDLEVEL is the pyramid level of the raster data. A PYRAMIDLEVEL of 0 indicates the data is at its original r

44、esolution, and at each increasing integer level indicates the reduction in resolution by a factor of two.BANDBLOCKNUMBER, ROWBLOCKNUMBER, and COLUMNBLOCKNUMBER are all defined in terms of the BLOCKSIZE the user or application chooses for the storage parameters of the raster data. These will be discu

45、ssed in a future slide.SDO_RASTER Object Type BLOCKMBR is the Minimum Bounding Rectangle around the the data stored in the block SDO_GEOMETRY type In cell coordinate space SDO_SRID = NULL All coordinates are integers (minimum row/column and maximum row/column) Currently not used, will be used for ir

46、regular blockingRASTERBOCK contains the raster cell data for the given block BLOB type (Binary Large OBject)Raster Data Table A raster data table is an object table that contains GeoRaster data. Only data of type SDO_RASTER Can be created by Oracle Spatial GeoRaster Can be created by user GeoRaster

47、in the DatabaseGeoRaster DatabaseOther related tables (VAT, LUT, and others)Table with GeoRaster Column.GeoRaster System DataRaster data table.BLOBsMapping Between SDO_GEORASTER Objects and SDO_RASTER Tables XXX_SDO_GEOR_SYSDATATABLE_NAMECOLUMN_NAMERDT_TABLE_NAMERASTERIDSDO_GEORASTERRasterDataTableR

48、asterIDTable with GeoRasterSDO_RASTERRasterID . . .SDO_RASTERRasterIdRaster Data TableLoading GeoRaster DataExample with server-side loader fileName := t_dir|/tgrimg2.tif;select georaster into geor from georaster_table where georid = 2 for update;mdsys.sdo_geor.importFrom(GeoTIFF,file, fileName,rebl

49、ock=true, blockSizeX=512,blockSizeY=512,geor);update georaster_table set georaster = geor where georid = 2;commit;Operations on GeoRaster ObjectsSDO_GEOR.copySDO_GEOR.changeFormat & changeFormatCopySDO_GEOR.subsetSDO_GEOR.scale and scaleCopySDO_GEOR.generatePyramid and deletePyramidSDO_GEOR.generate

50、SpatialExtentSDO_GEOR.mosaic And others ExportSDO_GEOR.exportTo will export GeoRaster objects to image files:ESRI World FileTIFF, JPEG, etc.But it will be very limited supportViewing GeoRaster DataTwo choices:Call exportTo to export georaster objects to image files and display them using standard br

51、owsers or toolsUse the simple standalone GeoRaster Viewer provided with GeoRasterOracle Spatial FeaturesG1G2G3G4G5n4e5f1f2f3f0n1n2n3n5n6n7n8n9e1e2e3e4e6e7e8e9e10Object ViewTopology ViewTopology in the DatabaseDatabase componentStorage of the topology and related featuresMetadata views Procedures to

52、create and populate topology related structuresSQL procedures to do validation of the topology Spatial index for topological dataRead-only applications using the topology data model and corresponding features should use the SQL interfaces in the database Topology JAVA APIJAVA componentA toolkit for

53、developing editing applications based on topological data modelEditing applications must use the JAVA API to manage all the topology editing operationsAdd to a topologyRemove topological elementsUpdate topologyInternally, the JAVA API ensures the necessary relationships between features and the topo

54、logical elements the features are composed of remain consistentFeature ModelHow do users/applications map features to the topological elements the features are composed of?For instance:Determine the street name associated with a particular edgeDisplay the faces (parcel) given a map/lot number Users/

55、Applications create feature tablesStore attribute information associated with spatial featuresOne feature table for each layerFeature Model ExampleExamples of area/linear/point featuresF1E7E6E4E5E3E2E1F2N1N2N6N3N5N4Linear Feature: (E1,-E2)Point Feature: (N3)Area Feature: (F1,F2)Spatial Feature Table

56、sCreate Table Land_Parcels (ParcelKey NUMBER PRIMARY KEY,BookID VARCHAR2(15) MapID VARCHAR2(15),ParcelID VARCHAR2(15),Owner VARCHAR2(30),Other attributes if requiredFeature SDO_TOPO_GEOMETRY);The new type, SDO_TOPO_GEOMETRY, is added for topology. A constructor is used with this type for relating to

57、pological elements and feature attributes, and a user-defined constructor is used when loading attributes associated with topological elementsSpatial Topo-Geometry LayerColumn of type SDO_TOPO_GEOMETRY in a TableSimilar concept to SDO_GEOMETRY layerFrom an application point of view, this is similar

58、to current geometry layerEach layer has a unique ID in a topologyTopology Manager manages metadata for each Topo-Geometry layerUSER_SDO_TOPO_INFOALL_SDO_TOPO_INFOSDO_TOPO_GEOMETRYSQL describe sdo_topo_geometry Name Null? Type - - - TG_TYPE NUMBER TG_ID NUMBER TG_LAYER_ID NUMBER TOPOLOGY_ID NUMBERMET

59、HOD-MEMBER FUNCTION GET_GEOMETRY RETURNS SDO_GEOMETRYSDO_TOPO_GEOMETRYSimilar in concept to SDO_GEOMETRYTG_TYPE - Type of topology geometry 1 = point or multipoint 2 = line or multi-line 3 = polygon or multi-polygon4 = heterogeneous collectionTG_ID - Unique ID (generated by Spatial) for the topology

60、 geometryTG_LAYER_ID - System-assigned ID for the topology geometry layer This number is unique within the topology geometry layerTOPOLOGY_ID Unique ID of the topologySDO_TOPO_GEOMETRY Constructor (1)TOPOLOGY is the name of the topology, specified when the topology was created TG_TYPE is the Geometr