A spatial database has following types of tables:
GEOMETRY_COLUMNS
SPATIAL_REF_SYS
FEATURE TABLE
GEOMETRY TABLE
GEOMETRY_COLMNS table
Each Geometry Column in the database has an entry in the table. The data consists of the following:
1. id of feature table that the column in;
2. name of the geometry column;
3. srid of the column;
4. type of the geometry column;
5. coordinate dimension of the column;
6. the geometry table(which stores geometry data)'s id;
7. "the information necessary to navigate the geometry table in the case of normalized geometry storage."
SPATIAL_REF_SYS table
columns in this table:
1. SRID
2. AUTH_SRID
3. AUTH_NAME
4. SRTEXT(Well-Known Text for the SR)
Feature tables
a normal table with a foreign key to real geometry table.
Geometry tables
1. Normalized geometry schema
a normalized geometry schema stores coordinates of geometric objects as predefined SQL numeric types.
1. ETYPE, the geometry type;
2. ESEQ, id for each element (design for geometryCollection);
3. SEQ, the sequence of element in a geometry collection;
4. holes for polygon;
5. SEQ designates the part order of PolygonRings;
6. not used coordinates will be set null;
7. for the geometric objects that continus onto another row, the last point of the previous row will be same as the first of next row;
8. no limit on the number of geometric elements and number of rows in an element.
2. Binary geometry schema
geometry object as well as its bounding box(MBR) will be stored. the table consist of
GID, XMIN, XMAX, YMIN, YMAX, WKB
ANNOTATIONS metadata table
.......