Obtaining storage characteristics

For most smart large objects, all you need to do is obtain the system-specified storage characteristics. When you obtain these storage characteristics for a smart large object, you can specify a location for it and override system-specified attributes.

1. Use the mi_lo_spec_init() function to allocate an LO-specification structure and to initialize this structure to the appropriate null values.

   When a storage characteristic in the LO-specification structure has the appropriate null value (zero or a NULL-valued pointer), the smart-large-object optimizer obtains the system-specified value for the storage characteristic. The smart-large-object optimizer calculates the system-specified values for disk-storage storage characteristics. Most applications can use these system-specified values. For more information, see System-specified storage characteristics.

2. Specify the location of the smart large object to override the default location. You can specify the location as one of the following:
   • The name of the sbspace associated with the CLOB or BLOB column in which you want to store the smart large object

     To store a new smart large object in a CLOB or BLOB column, use the mi_lo_colinfo_by_name() or mi_lo_colinfo_by_ids() function. These functions obtain the column-level storage characteristics for this column. One of the storage characteristics they obtain is the sbspace name for the column. For more information, see Obtain column-level storage characteristics.

   • The name of some other sbspace

     You might want to specify an sbspace name for a new smart large object that is embedded in an opaque data type. The mi_lo_specset_sbspace() accessor function sets the name of the sbspace in the LO-specification structure. For more information, see Define user-specified storage characteristics.

3. Optional: Override any attributes for the smart large object with the mi_lo_specset_flags() accessor function.

   The system-specified attributes have both logging and last-access time disabled. You might want to enable one or more attributes for the new smart large object. The mi_lo_specset_flags() function sets the attributes flag in the LO-specification structure. For more information, see Define user-specified storage characteristics.

4. Pass this LO-specification structure to one of the smart-large-object creation functions (mi_lo_create(), mi_lo_copy(), mi_lo_expand(), or mi_lo_from_file()) to create the smart large object.

   The smart-large-object creation function creates a smart large object that has storage characteristics that the LO-specification structure indicates. For more information, see Initialize an LO-specification structure.