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FAQ: What are appropriate values for the SDE DBTUNE parameter st_geom_lob_storage?

Question

What are appropriate values for the SDE DBTUNE parameter st_geom_lob_storage?

Answer

The ArcSDE DBTUNE parameter, st_geom_lob_storage, is used for defining the storage characteristics of the ST_Geometry attribute, the ST_Geometry points attribute's LOB segment storage, and the LOB's segment index.

The following example demonstrates a valid configuration string for the st_geom_lob_storage parameter, which defines the ST_Geometry attribute's storage characteristics, the point attribute's LOB segment storage characteristics, and the LOB's segment index storage characteristics.

Code:
ST_GEOM_LOB_STORAGE "STORE AS (
ENABLE STORAGE IN ROW CHUNK 8K RETENTION CACHE
TABLESPACE users_data STORAGE (INITIAL 500M PCTINCREASE 10)
INDEX (TABLESPACE users_lob_idx STORAGE (INITIAL 50M PCTINCREASE 10)))"

When the feature class is created, the ST_Geometry LOB's points are stored in the users_data tablespace with an initial 500M extents and the next extent increases by 10 percent. The ST_Geometry points LOB index is created in the users_lob_idx tables, and the initial extent is 50M and the next extent increases by 10 percent.

Note:
Oracle recommends not to define the name of the LOB segment's index and storage clause as demonstrated above and in the ArcSDE dbtune file 'INDEX (TABLESPACE users_lob_idx STORAGE (INITIAL 50M PCTINCREASE 10))'. See the following knowledge base article: Should the Oracle LOB segment's index name be specified when creating an ST_Geometry attribute? for additional information.

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