The column-level storage characteristics

The database administrator (DBA) assigns column-level storage characteristics with the CREATE TABLE statement. The PUT clause of CREATE TABLE specifies storage characteristics for a particular smart-large-object (CLOB or BLOB) column. (For more information, see the description of the CREATE TABLE statement in the Informix® Guide to SQL: Syntax.) The syscolattribs system catalog table stores column-level storage characteristics.

The ifx_lo_col_info() function obtains column-level storage characteristics for a smart-large-object column. To use the column-level storage characteristics for a new smart-large-object instance, follow these steps:
  1. Use the ifx_lo_def_create_spec() function to allocate an LO-specification structure and initialize this structure to null values.
  2. Pass this LO-specification structure to the ifx_lo_col_info() function and specify the desired column and table name as arguments.

    The function stores the column-level storage characteristics into the specified LO-specification structure.

  3. Pass this same LO-specification structure to the ifx_lo_create() function to create the instance of the smart large object.

When the ifx_lo_create() function receives the LO-specification structure as an argument, this structure contains the column-level storage characteristics that the previous call to ifx_lo_col_info() stored. Therefore, the database server assigns these column-level characteristics to the new instance of the smart large object.

When you use the column-level storage characteristics, you do not usually need to provide the name of the sbspace for the smart large object. The sbspace name is specified in the PUT clause of the CREATE TABLE statement or by the SBSPACENAME parameter in the ONCONFIG file.