常见问题解答：用户是否可以在 dbtune 文件中设置 LOB 存储语法？

答案

Note:
ArcSDE software, including the application server, command tools, and SDK with C and Java APIs, was deprecated at ArcGIS 10.2.2 and is no longer distributed.

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 examples demonstrate 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 Esri Technical 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.