Enscribe Programmer's Guide

Figures
1 A Record With Three Fields in a Structured File....................................................................25
2 Primary Keys in Structured Files..........................................................................................26
3 An Alternate-Key Field......................................................................................................26
4 Using Key Values to Locate Records....................................................................................27
5 Access Paths....................................................................................................................28
6 Key Fields and Key Specifiers.............................................................................................29
7 Current Position................................................................................................................29
8 Approximate, Generic, and Exact Subsets...........................................................................30
9 Alternate-Key Implementation.............................................................................................32
10 Record Structure of an Alternate-Key File.............................................................................35
11 Relational Access Among Structured Files............................................................................38
12 Example of Encountering the EOF......................................................................................66
13 Example of Encountering the EOF (Short READ)...................................................................66
14 Key-Sequenced B-Tree Structure..........................................................................................70
15 Queue File Record Format...............................................................................................108
16 Dequeuing a Record......................................................................................................112
17 Using Approximate Positioning With a Queue File..............................................................115
18 Using Generic Positioning With a Queue File....................................................................116
19 Entry-Sequenced File Structure.........................................................................................124
20 Relative File Structure......................................................................................................134
21 Record Locking for TMF..................................................................................................156
22 Record Locking by Transid...............................................................................................157
23 Example Showing Extent-Allocation Error..........................................................................160
24 Block Format for Structured Format 1 Files.........................................................................170
25 Index Block Header for Key-Sequenced and Queue Files.....................................................172
26 Data Block Header for Key-Sequenced and Queue Files......................................................172
27 Header for Entry-Sequenced Data Block............................................................................173
28 Header for Relative Data Block........................................................................................173
29 Header for Bit-Map Block................................................................................................174
30 Arrangement of Bit-Map Blocks........................................................................................174
31 Block Format for Structured Format 2 Files.........................................................................175
32 Index Block Header for Key-Sequenced and Queue Format 2 Files.......................................177
33 Data Block Header for Key-Sequenced and Queue Format 2 Files........................................177
34 Header for Format 2 Entry-Sequenced Data Block..............................................................178
35 Header for Format 2 Relative Data Block...........................................................................178
36 Header for Bit-Map Block................................................................................................179
Tables
1 SPR Requirements for Increased Enscribe Limits for the H06.28/J06.17 Release........................18
2 Record Management Functions Summary............................................................................23
3 Comparison of Structured Files...........................................................................................24
4 File-System Procedures......................................................................................................39
5 Error Number Categories..................................................................................................43
6 SIO Procedures................................................................................................................44
7 Comparison of Format 1 Versus Format 2 Files.....................................................................47
8 File-Pointer Action.............................................................................................................64
9 Comparison of LKS Files, LKS2 Files, Standard Queue Files, EKS Files, and EKS Files with
Increased Limits...............................................................................................................71
10 Converting LKS Files to EKS Files........................................................................................73