I/O feedback area for database files

The table in this topic shows the I/O feedback area for database files.

Table 1. I/O feedback area for database files
Offset Data type Length Contents
0 Binary 4 Size of the database feedback area, including the key and the null key field byte map.
4 Character 4
Bits 1-32:
Each bit represents a join logical file in JFILE keyword.
0
JDFTVAL not supplied for file
1
JDFTVAL supplied for file
8 Binary 2 Offset from the beginning of the I/O feedback area for database files to the null key field byte map which follows the key value (which begins at offset 34 in this area).
10 Binary 2 Number of locked records.
12 Binary 2 Maximum number of fields.
14 Binary 4 Offset to the field-mapping error-bit map.
18 Character 1 Current file position indication.
Bit 1:
Current file position is valid for get-next-key equal operation.
0
File position is not valid.
1
File position is valid.
Bits 2-8:
Reserved.
19 Character 1 Current record deleted indication:
Bits 1-2:
Reserved.
Bit 3:
Next message indicator.
0
Next message not end of file.
1
Next message might be end of file.
Bit 4:
Deleted record indicator.
0
Current file position is at an active record.
1
Current file position is at a deleted record.
Bit 5:
Write operation key feedback indicator.
0
Key feedback is not provided by last write operation.
1
Key feedback is provided by last write operation.
Bit 6:
File position changed indicator. Set only for read and positioning I/O operations. Not set for write, update, and delete I/O operations.
0
File position did not change.
1
File position did change.
Bit 7:
Pending exception indicator. Valid for files open for input only and SEQONLY(*YES N) where N is greater than 1.
0
Pending retrieval error does not exist.
1
Pending retrieval error does exist.
Bit 8:
Duplicate key indicator.
0
The key of the last read or write operation was not a duplicate key.
1
The key of the last read or write operation was a duplicate key.
20 Binary 2 Number of key fields. Use this offset for binary operations. Use the next offset (offset 21) for character operations. These offsets overlap and provide the same value (there can be no more than 32 key fields, and only the low-order byte of offset 20 is used).
21 Character 1 Number of key fields.
22 Character 4 Reserved.
26 Binary 2 Key length.
28 Binary 2 Data member number.
30 Binary 4 Relative record number in data member.
34 Character * Key value.
* Character * Null key field byte map.
Parent topic: I/O feedback area