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How To: Setup a Keyword for loading Raster Data into ArcSDE

Summary

This is an example of a DBTUNE keyword that could be used when loading Raster data into ArcSDE. It is recommended that you become familiar with the related links for background information on why these settings were chosen. For information on how to create a DBTUNE keyword, refer to the ArcSDE Configuration and Tuning Guide.

Procedure

The following is an example of a DBTUNE keyword that could be used when loading Raster data into ArcSDE (see your ArcSDE Configuration and Tuning Guide for information on how to create a dbtune keyword and a detailed list of the raster storage parameters).

  • Refer to the Oracle White paper How to stop Defragmenting and Start Living for details regarding why the following settings were chosen.

    Refer to Raster Data in ArcSDE 8.3 for details of the schema used to store a raster in ArcSDE
  • Large Rasters require customized storage.
  • The BLK table will become LARGE. Create a separate tablespace to store it in and ensure no other data is stored in this tablespace.
  • Other segments associated with a Raster are small. Use a separate tablespace with small extents to avoid over allocating space.
  • Use Locally Managed Uniform Extents with Automatic Segment Space Management.
  • For the BLK table, consider using the following extent sizes
    . If the BLK table is smaller than 128M, use 128K extents
    . If the BLK table is between 128M and 4G, use 4M extents
    . If the BLK table is larger than 4G, use 128M extents
  • Use 16K block size or larger.
  • For large raster loads, load a sample to estimate the total storage requirements.
  • You will need to consider the maximum database file size you want to use. Generally, it is not good to exceed 2 GB for a file size.
  • An example of the tablespaces you could use is:

    Code:
    CREATE TABLESPACE "RASTER_BLK_TABLE"
    DATAFILE '/ora920/oradata/ora920/RASTER_BLK_TABLE_01.dbf'
    SIZE 402M
    EXTENT MANAGEMENT LOCAL UNIFORM SIZE 4M
    SEGMENT SPACE MANAGEMENT AUTO
    CREATE TABLESPACE "RASTER_DATA"
    DATAFILE '/ora920/oradata/ora920/RASTER_DATA_01.dbf'
    SIZE 2M
    EXTENT MANAGEMENT LOCAL UNIFORM SIZE 128K
    SEGMENT SPACE MANAGEMENT AUTO

  • An example of the keyword, using these tablespace is:

    Code:
    ##RASTER
    AUX_INDEX_COMPOSITE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    AUX_STORAGE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"

    BLK_INDEX_COMPOSITE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    BLK_STORAGE "TABLESPACE RASTER_BLK_TABLE PCTFREE 10 INITRANS 4"

    BND_INDEX_COMPOSITE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    BND_INDEX_ID "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    BND_STORAGE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"

    B_INDEX_ROWID "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    B_INDEX_SHAPE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    B_INDEX_USER "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    B_STORAGE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"

    RAS_INDEX_ID "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    RAS_STORAGE "TABLESPACE RASTER_DATA PCTFREE 10 INITRANS 4"
    END

  • This example is for data being loaded into tablespaces that were created using Locally Managed Uniform extents; therefore, all settings in relation to table extents were deliberately omitted from the dbtune string.
  • This information is covered in detail in the 'ArcSDE Administration for Oracle' Training course.
  • Add the keyword to the dbtune table with the 'sdedbtune' administration command. Ensure you use the keyword when loading the raster data.

  • Note:
    Once the data is loaded, ensure you compute the statistics. Failure to do so will cause poor performance, due to the poor execution plan Oracle chooses using the Cost Based Optimizer when the statistics are absent. Use Oracle dbms_stats package to calculate the statistics.

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