which of the following materials may be used as grid interspace material:
1. lead
2. plastic
3. aluminum
a. 1 only
b. 1 and 2 only
c. 2 and 3 only
d. 1,2 and 3
-------------------------
The spatial grid index:
Geodatabases in Oracle and DB2 use grid indexes. The spatial index is created by applying a grid to the data in the spatial column. The spatial grid index is two-dimensional and encompasses a feature class similar to the reference grid that you might find on a common road map. You can assign the spatial grid index one, two or three levels, each with its own cell size. The first mandatory grid level has the smallest cell size. The second and third optional grid cell levels are disabled by setting their values to 0. If enabled, the second grid cell size must be at least three times larger than the first grid cell size, and the third size The grid cell must be three times larger than the second.
In the following example, the feature class has two grid levels. Area form 101 is located in a grid cell 4 of level 1. A record is added to the spatial index table because the entity resides in less than four grid cells (in this case, in one). The envelope for area entity 102 is located in cells 1 to 8 at level 1. Since the entity's envelope resides in more than four grid cells, the entity is promoted to level 2, where its envelope conforms to Two grid cells. Entity 102 is indexed at level 2, and two records are added to the spatial index table.
Inserting, updating or deleting an entity updates the spatial index. The extent of each entity overlaps with the lowest grid level to obtain the number of grid cells. If the entity exceeds the value set for the MAXGRIDSPERFEAT value in the SERVER_CONFIG table, the geometry is promoted to the next higher grid level, if one has been defined.
For Oracle databases, you can specify the location where the spatial index is created if you set the S_STORAGE parameter of the configuration keyword that you use to create the feature class. See Oracle Configuration Parameters for information on how to set the values of the configuration parameters.
1. lead
2. plastic
3. aluminum
a. 1 only
b. 1 and 2 only
c. 2 and 3 only
d. 1,2 and 3
-------------------------
The spatial grid index:
Geodatabases in Oracle and DB2 use grid indexes. The spatial index is created by applying a grid to the data in the spatial column. The spatial grid index is two-dimensional and encompasses a feature class similar to the reference grid that you might find on a common road map. You can assign the spatial grid index one, two or three levels, each with its own cell size. The first mandatory grid level has the smallest cell size. The second and third optional grid cell levels are disabled by setting their values to 0. If enabled, the second grid cell size must be at least three times larger than the first grid cell size, and the third size The grid cell must be three times larger than the second.
In the following example, the feature class has two grid levels. Area form 101 is located in a grid cell 4 of level 1. A record is added to the spatial index table because the entity resides in less than four grid cells (in this case, in one). The envelope for area entity 102 is located in cells 1 to 8 at level 1. Since the entity's envelope resides in more than four grid cells, the entity is promoted to level 2, where its envelope conforms to Two grid cells. Entity 102 is indexed at level 2, and two records are added to the spatial index table.
Inserting, updating or deleting an entity updates the spatial index. The extent of each entity overlaps with the lowest grid level to obtain the number of grid cells. If the entity exceeds the value set for the MAXGRIDSPERFEAT value in the SERVER_CONFIG table, the geometry is promoted to the next higher grid level, if one has been defined.
For Oracle databases, you can specify the location where the spatial index is created if you set the S_STORAGE parameter of the configuration keyword that you use to create the feature class. See Oracle Configuration Parameters for information on how to set the values of the configuration parameters.
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