Oracle Spatial User's Guide and Reference - InfoLab

Usage Notes
SDO_TUNE.ESTIMATE_RTREE_INDEX_SIZE
partname
Name of a partition containing geometries from colname. If you specify this
parameter, the value returned by the function is the estimated size for an R-tree
index table on geometries in that partition. If you do not specify this parameter, the
value is the estimated size for an R-tree index table on all geometries in colname.
number_of_geoms
Approximate number of geometries in the spatial geometry table.
db_block_size
Database block size (in bytes).
sdo_rtr_pctfree
Minimum percentage of slots in each index tree node to be left empty when the
index is created. Slots that are left empty can be filled later when new data is
inserted into the table. The value can range from 0 to 50. The default value (10) is
best for most applications; however, a value of 0 is recommended if no updates will
be performed to the geometry column.
num_dimensions
Number of dimensions to be indexed. The default value is 2. If you plan to specify
the sdo_indx_dims parameter in the CREATE INDEX statement, the num_
dimensions value should match the sdo_indx_dims value.
is_geodetic
A value indicating whether or not the spatial index will be a geodetic index: 1 for a
geodetic index, or 0 (the default) for a non-geodetic index. (Section 4.1.2 explains
geodetic indexes.)
The function returns the estimated maximum number of megabytes needed for the
spatial index table (described in Section 2.5.2) for an R-tree spatial index to be
created. The value returned is the maximum number of megabytes needed after
index creation. During index creation, approximately three times this value of
megabytes will be needed in the tablespace, to ensure that there is enough space for
temporary tables while the index is being created.
This function has two formats:
■ Use the format with character string parameters (schemaname, tabname,
colname, and optionally partname) in most cases when the spatial geometry
table already exists, you do not plan to add substantially more geometries to it
Spatial Tuning Subprograms 18-5