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FAQ: Can users set the LOB storage syntax in a dbtune file?

Question

Can users set the LOB storage syntax in a dbtune file?

Answer

Yes. Users can add LOB (large object) storage syntax in the dbtune file to finely control the storage parameters for LOB columns in a feature class or in a raster dataset and raster catalog.

The following are examples of how to correctly specify the LOB storage syntax in a dbtune file to finely control the LOB storage parameters for raster dataset SDE_BLK table (for example, LOB segment tablespace and other storage options)

Example 1: To store SDE_BLK table in tablespace RASTER and store the LOB column BLOCK_DATA to tablespace RASTER_LOB_SEGMENT, see the Esri white paper 'Converting from LONG RAW to BLOB in an ArcSDE for Oracle geodatabase'.

On page 2:

Code:
BLK_STORAGE "PCTFREE 0 INITRANS 4
TABLESPACE RASTER
LOB (BLOCK_DATA) STORE AS
(TABLESPACE RASTER_LOB_SEGMENT
CACHE PCTVERSION 0)"

Example 2: To store SDE_BLK table in tablespace RASTER and store the LOB column BLOCK_DATA to tablespace RASTER_LOB_SEGMENT and add CACHE with NOLOGGING and some other options:

Code:
BLOCK_STORAGE "PCTFREE 0 INITRANS 4 TABLESPACE RASTER
LOB (BLOCK_DATA) STORE AS
(TABLESPACE RASTER_LOB_SEGMENT enable storage in
row CHUNK 8192 pctversion 0 CACHE reads NOLOGGING)"

Example 3: To store SDE_BLK table in tablespace RASTER and store the LOB column BLOCK_DATA to tablespace RASTER_LOB_SEGMENT and add NOCACHE with NOLOGGING and some other options

Code:
BLOCK_STORAGE "PCTFREE 0 INITRANS 4 TABLESPACE RASTER
LOB (BLOCK_DATA) STORE AS
(TABLESPACE RASTER_LOB_SEGMENT enable storage in
row CHUNK 8192 pctversion 0 NOCACHE NOLOGGING)"

An example RASTER dbtune keyword:

Code:
##RASTER
ATTRIBUTE_BINARY "BLOB"
UI_TEXT "User Interface text for RASTER"
RASTER_STORAGE "BLOB"
BLOCK_STORAGE "PCTFREE 0 INITRANS 4 TABLESPACE RASTER
LOB (BLOCK_DATA) STORE AS(TABLESPACE RASTER_LOB_SEGMENT enable storage in row CHUNK 8192 pctversion 0 NOCACHE NOLOGGING)"
END

When a user creates a raster dataset with the above RASTER dbtune keyword, the SDE_BLK table will be stored in tablespace RASTER and the LOB segment for column BLOCK_DATA will be stored in tablespace RASTER_LOB_SEGMENT.
Note:
When combining the CACHE with the NOLOGGING, use CACHE READS NOLOGGING.

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