Disk-storage information
The LO-specification structure stores disk-storage information, which helps the database server determine how to store the smart large object most efficiently on disk.
The following table shows the disk-storage information along with the corresponding access functions.
| Disk-storage information | Description | ESQL/C accessor functions |
|---|---|---|
| Estimated number of bytes | An estimate of the final size, in bytes, of the smart large object. The database server uses this value to determine the extents in which to store the smart large object. This value provides optimization information. If the value is grossly incorrect, it does not cause incorrect behavior. However, it does mean that the database server might not necessarily choose optimal extent sizes for the smart large object. | ifx_lo_specget_estbytes() ifx_lo_specset_estbytes() |
| Maximum number of bytes | The maximum size, in bytes, for the smart large object. The database server does not allow the smart large object to grow beyond this size. | ifx_lo_specget_maxbytes() ifx_lo_specset_maxbytes() |
| Allocation extent size | The allocation extent size is specified in kilobytes.
Optimally, the allocation extent is the single extent in a chunk that
holds all the data for the smart large object. The database server performs storage allocations for smart large objects in increments of the allocation extent size. It tries to allocate an allocation extent as a single extent in a chunk. However, if no single extent is large enough, the database server must use multiple extents as necessary to satisfy the request. |
ifx_lo_sepcget_extsz(), ifx_lo_specset_extsz() |
| Name of the sbspace | The name of the sbspace that contains the smart large object. The sbspace name can be at most 18 characters long. This name must be null terminated. | ifx_lo_specget_sbspace() ifx_lo_specset_sbspace() |
For most applications, it is recommended that you use the values for the disk-storage information that the database server determines.