Enscribe Programmer's Guide

Figure 24 Block Format for Structured Format 1 Files
byte offset from [0] to record N
(key-sequenced, queue, and
entry-sequenced files only)
size of record N
(relative file only)
size of record 0
(relative file only)
eye-catcher
relative-sector-number
flags
index-level
volume-sequence-number
checksum
type-specific-block-header
(record 0)
(record 1)
(record N, where N = number-of-records -1)
free space (key-sequenced, queue, and
entry-sequenced files only)
byte offset from [0] to start of free space (reserved)
Decimal
Offset
[0]
[1]
[4]
[5]
[6]
[12]
[blocksize
- 2]
[14]
[18, 20,
24, or
30]
Length
in
Bytes
1
3
1
1
6
2
[4, 6,
10, or
16]
2
2
2
Common
Block
Header
Data
Area
Offsets
Map or
Record-
size
Array
byte offset from [0] to record 0
(key-sequenced, queue, and
entry-sequenced files only)
The fields in Figure 24 are defined as:
eye-catcher
is currently set to > but could be changed in a future release.
relative-sector-number
identifies the relative 512-byte sector within the file.
flags
Bit 0: This bit is set (=1) if the block is broken (inconsistent).
Bits 1 and 2: These two bits are reserved for decompression and are used internally for SQL
compression logic.
170 Block Formats of Structured Files