HP 3000 Manuals HP 3000 Manuals
HP 3000 Computer Systems Row Level Locking: Technical Addendum for ALLBASE/SQL Release F HP Part No. 36216-90085 Printed in U.S.A. Edition First Edition E0792
________________________________________________________________________ |The information contained in this document is subject to change | |without notice. | | | |HEWLETT-PACKARD MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS | |MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Hewlett-Packard | |shall not be liable for errors contained herein or use of this | |material. | | | |Hewlett-Packard assumes no responsibility for the use or reliability | |of its software on equipment that is not furnished by Hewlett-Packard.| | | |This document contains proprietary information which is protected by | |copyright. All rights are reserved. No part of this document may be | |photocopied, reproduced, or translated to another language without the| |prior written consent of Hewlett-Packard Company. | ________________________________________________________________________ Copyright (c)1992 by Hewlett-Packard Company Printed July 1992 Printing History The following table lists the printings of this document, together with the respective release dates for each edition. The software version indicates the version of the software product at the time this document was issued. Many product releases do not require changes to the document. Therefore, do not expect a one-to-one correspondence between product releases and document editions. Edition Date Software Version --------------------------------------------------------------------------------------- First Edition July 1992 36216-02A.F0.00
NOTE The F.0 release of ALLBASE/SQL is compatible with the 4.0 release of the MPE/iX operating system.
Preface This publication describes the use of row (tuple) level locking in ALLBASE/SQL. The following chapters describe only the new functionality in a supplement to the ALLBASE/SQL documentation set for the F.0 release. Each chapter assumes a knowledge of the ALLBASE/SQL product. You are referred to other manuals in the regular ALLBASE/SQL documentation set for the F.0 release for further information or related details. The chapters are organized as follows: "Creating and Using Tables with Row Level Locking" provides specific information on creating tables that employ this feature. Guidelines are provided to help you understand when and when not to use row level locking in your tables. Material in this chapter complements the "Using ALLBASE/SQL" chapter in the ALLBASE/SQL Reference Manual and the "Database Creation and Security" chapter of the ALLBASE/SQL Database Administration Guide. The section on "Memory Management with Row Level Locking" supplements the "Physical Design" chapter of the ALLBASE/SQL Database Administration Guide. "Concurrency Control through Locks and Isolation Levels" is a new version of the chapter of the same name in the ALLBASE/SQL Reference Manual. "Syntax and System Catalog Changes for Row Level Locking" provides the new syntax and description of the ALTER TABLE and CREATE TABLE statements together with a revised description of the system view SYSTEM.TABLE. Material in this chapter supersedes the information for the same statements in the "SQL Statements" chapter of the ALLBASE/SQL Reference Manual and for the SYSTEM.TABLE view in the ALLBASE/SQL Database Administration Guide. For additional information on ALLBASE/SQL syntax, refer to the ALLBASE/SQL Reference Manual. "Messages for Row Level Locking" provides the new and revised messages related to row level locking. This chapter supplements the ALLBASE/SQL Message Manual. Conventions UPPERCASE In a syntax statement, commands and keywords are shown in uppercase characters. The characters must be entered in the order shown; however, you can enter the characters in either uppercase or lowercase. For example: COMMAND can be entered as any of the following: command Command COMMAND It cannot, however, be entered as: comm com_mand comamnd italics In a syntax statement or an example, a word in italics represents a parameter or argument that you must replace with the actual value. In the following example, you must replace filename with the name of the file: COMMAND filename bold italics In a syntax statement, a word in bold italics represents a parameter that you must replace with the actual value. In the following example, you must replace filename with the name of the file: COMMAND(filename) punctuation In a syntax statement, punctuation characters (other than brackets, braces, vertical bars, and ellipses) must be entered exactly as shown. In the following example, the parentheses and colon must be entered: (filename):(filename) underlining Within an example that contains interactive dialog, user input and user responses to prompts are indicated by underlining. In the following example, yes is the user's response to the prompt: Do you want to continue? >> yes { } In a syntax statement, braces enclose required elements. When several elements are stacked within braces, you must select one. In the following example, you must select either ON or OFF: COMMAND { ON } { OFF} [ ] In a syntax statement, brackets enclose optional elements. In the following example, OPTION can be omitted: COMMAND filename [OPTION] When several elements are stacked within brackets, you can select one or none of the elements. In the following example, you can select OPTION or parameter or neither. The elements cannot be repeated. COMMAND filename [ OPTION ] [ parameter] Conventions (continued) [...] In a syntax statement, horizontal ellipses enclosed in brackets indicate that you can repeatedly select the element(s) that appear within the immediately preceding pair of brackets or braces. In the example below, you can select parameter zero or more times. Each instance of parameter must be preceded by a comma: [,parameter][...] In the example below, you only use the comma as a delimiter if parameter is repeated; no comma is used before the first occurrence of parameter: [parameter][,...] |...| In a syntax statement, horizontal ellipses enclosed in vertical bars indicate that you can select more than one element within the immediately preceding pair of brackets or braces. However, each particular element can only be selected once. In the following example, you must select A, AB, BA, or B. The elements cannot be repeated. { A} |...| { B} ... In an example, horizontal or vertical ellipses indicate where portions of an example have been omitted. In a syntax statement, the space symbol shows a required blank. In the following example, parameter and parameter must be separated with a blank: (parameter) (parameter) The symbol indicates a key on the keyboard. For example, RETURN represents the carriage return key or Shift represents the shift key. CTRLcharacterCTRLcharacter indicates a control character. For example, CTRLY means that you press the control key and the Y key simultaneously.