The mi_lo_specset_estbytes() function
The mi_lo_specset_estbytes() function sets the estimated size of a smart large object.
Syntax
mi_integer mi_lo_specset_estbytes(LO_spec, estbytes)
MI_LO_SPEC *LO_spec;
mi_int8 *estbytes;
- LO_spec
- A pointer to the LO-specification structure in which to save the estimated size.
- estbytes
- A pointer to an eight-byte integer (mi_int8) that contains the desired estimated number of bytes for the smart large object.
Valid in client LIBMI application? | Valid in user-defined routine? |
---|---|
Yes | Yes |
Usage
The mi_lo_specset_estbytes() function
is the LO-specification accessor function that sets the estimated
size for a new smart large object. The estbytes value is the
estimated final size, in bytes, of the smart large object. This estimate
is an optimization hint for the smart-large-object optimizer.
Important: Before you call mi_lo_specset_estbytes(),
you must initialize an LO-specification structure.
After you set the estimated size in an LO-specification structure, you pass this structure to a smart-large-object creation function (such as mi_lo_create()) to provide the estimated size as a user-supplied storage characteristic for a new smart large object.
The smart-large-object optimizer
attempts to optimize the extent size based on past operations on the
smart large object and other storage characteristics (such as maximum
bytes) that it obtains from the storage-characteristics hierarchy.
Most applications can use the size estimate that the smart-large-object
optimizer generates.
Important: Do not specify an estimated
size unless you have enough information about the data to provide
a useful estimate. If you do set the estimated size for a smart large
object, do not specify a value much higher than the final size of
the smart large object. Otherwise, the database server might allocate
unused storage.
For more information about the estimated size of a smart large object or about how to use the mi_lo_specset_estbytes() function, see the Informix® DataBlade® API Programmer's Guide.
Return values
- MI_OK
- The function was successful.
- MI_ERROR
- The function was not successful.