Step First (33)
The Step First operation (B_STEP_FIRST) retrieves the first physical record of the file. The MicroKernel Engine does not use a key path to retrieve the record.
Parameters
 
Op Code
Pos Block
Data Buf
Data Buf Len
Key Buffer
Key Number
Sent
* 
* 
 
* 
 
 
Returned
 
* 
* 
* 
 
 
Prerequisites
The file must be open.
Procedure
1
Set the operation code to 33. Optionally, you can include a lock bias:
•
+100 – Single wait record lock.
•
+200 – Single no-wait record lock.
•
+300 – Multiple wait record lock.
•
+400 – Multiple no-wait record lock.
For more information about locking, refer to the PSQL Programmer's Guide.
2
Pass the position block for the file.
3
Set the data buffer length to a value greater than or equal to the length of the record to retrieve.
Result
If the Step First operation is successful, the MicroKernel Engine returns the file’s first physical record in the data buffer and sets the data buffer length parameter to the number of bytes returned.
If the Step First operation is unsuccessful, the MicroKernel Engine returns one of the following status codes:
3
The file is not open.
9
The operation encountered the end-of-file.
22
The data buffer parameter is too short.
Positioning
The Step First operation destroys logical currency. Step First sets the physical currency using the retrieved record as the physical current record. The previous physical position points beyond the beginning of the file.