Managing file and table sizes - Revision history

JAL: misc cleanup

2017-03-21T21:40:37Z

misc cleanup

ELowell: /* Adding new pages with the INCREASE DATASETS command */

2015-08-05T16:33:53Z

Adding new pages with the INCREASE DATASETS command

← Older revision		Revision as of 16:33, 5 August 2015
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	</p>		</p>
	<p>		<p>
	The lettered blocks in ~~[[#Adding new pages with~~ the ~~INCREASE DATASETS command\|Adding new pages with the INCREASE DATASETS command]] and [[#Adding new pages with the INCREASE DATASETS command\|Adding new pages with the INCREASE DATASETS command]]~~ represent pages for Tables A, B, C, D, and E; the F blocks represent free pages (or FREESIZE). Now you have added all of the pages in YOURF2 to FREESIZE in YOURFILE.</p>		The lettered blocks in the following figures represent pages for Tables A, B, C, D, and E; the F blocks represent free pages (or FREESIZE). Now you have added all of the pages in YOURF2 to FREESIZE in YOURFILE.</p>
	<table>		<table>
	<caption>YOURFILE</caption>		<caption>YOURFILE</caption>
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	INCREASE DATASETS WITH CARS3		INCREASE DATASETS WITH CARS3
	EOJ		EOJ
	</p>		</p>

	==Automatic increases==		==Automatic increases==
	Perhaps the worst thing that can happen to a File Manager are system outages due to tables within files becoming full during processing. To prevent tables from becoming full, some of the functions described above can be automated so that table sizes are changed as needed.		Perhaps the worst thing that can happen to a File Manager are system outages due to tables within files becoming full during processing. To prevent tables from becoming full, some of the functions described above can be automated so that table sizes are changed as needed.

ELowell: /* MAXINCBP parameter */

2015-08-05T16:30:20Z

MAXINCBP parameter

← Older revision		Revision as of 16:30, 5 August 2015
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	Even with the <var>DYNAMIC</var> option, you can only increase the size to the next segment boundary. (The number of segments in a file is used as part of the procedure compilation.) This limitation can be alleviated by setting the <var>[[MAXINCBP parameter\|MAXINCBP]]</var> parameter. </p>		Even with the <var>DYNAMIC</var> option, you can only increase the size to the next segment boundary. (The number of segments in a file is used as part of the procedure compilation.) This limitation can be alleviated by setting the <var>[[MAXINCBP parameter\|MAXINCBP]]</var> parameter. </p>
	<p>		<p>
	The <var>MAXINCBP</var> system parameter sets a limit, as a percentage of <var>BSIZE</var>, on how much Table B can be increased, by the INCREASE TABLE B command or by automatic increase (if <var>BAUTOINC</var> is also set). This percentage is then used to calculate the maximum number of segments, rounded up to a whole number, that the file could have if Table B were increased by the entire amount. The actual number of pages that <var>BSIZE<var> can increase to is determined by the calculated number of segments, divided by <var>BRECPPG</var>.</p>		The <var>MAXINCBP</var> system parameter sets a limit, as a percentage of <var>BSIZE</var>, on how much Table B can be increased, by the INCREASE TABLE B command or by automatic increase (if <var>BAUTOINC</var> is also set). This percentage is then used to calculate the maximum number of segments, rounded up to a whole number, that the file could have if Table B were increased by the entire amount. The actual number of pages that <var>BSIZE</var> can increase to is determined by the calculated number of segments, divided by <var>BRECPPG</var>.</p>
	<p>		<p>
	The compiler uses the maximum possible number of segments to determine the correct length of the entries it allocates in the resource locking table and in VTBL. During compilation the file is treated as though it has already been increased to the maximum number of segments (<var>MAXINCBP</var>) even though no increase may yet have occurred.</p>		The compiler uses the maximum possible number of segments to determine the correct length of the entries it allocates in the resource locking table and in VTBL. During compilation the file is treated as though it has already been increased to the maximum number of segments (<var>MAXINCBP</var>) even though no increase may yet have occurred.</p>
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	<p>		<p>
	The <var>MAXINCBP</var> parameter is ignored for any sorted or hash key files.</p>		The <var>MAXINCBP</var> parameter is ignored for any sorted or hash key files.</p>

	====Example of Table B increase====		====Example of Table B increase====
	<p>		<p>

ELowell at 21:11, 13 April 2015

2015-04-13T21:11:33Z

← Older revision		Revision as of 21:11, 13 April 2015
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	<div class="toclimit-3">		<div class="toclimit-3">
	<p>		<p>
	When you create a file and its tables, whether you use the calculations described in [[File ~~size calculation~~]] to size the tables or the rules of thumb that an experienced File Manager develops over time, there is always some space for growth included. When a <var class="product">Model 204</var> file is created, exact disk space requirements are seldom known. Even if perfect, eventually, it will be necessary to revise the space utilized in a file. </p>		When you create a file and its tables, whether you use the calculations described in [[File sizing introduction]] to size the tables or the rules of thumb that an experienced File Manager develops over time, there is always some space for growth included. When a <var class="product">Model 204</var> file is created, exact disk space requirements are seldom known. Even if perfect, eventually, it will be necessary to revise the space utilized in a file. </p>

	There are three ways to maintain table sizes:		There are three ways to maintain table sizes:

JAL: typo

2014-12-03T20:59:14Z

typo

← Older revision		Revision as of 20:59, 3 December 2014
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	<td>Segment boundaries need to be taken into account.<p>The <var>[[MAXINCBP parameter\|MAXINCBP]]</var> parameter needs to be set if you want to increase Table B beyond the current segment boundary. </p>		<td>Segment boundaries need to be taken into account.<p>The <var>[[MAXINCBP parameter\|MAXINCBP]]</var> parameter needs to be set if you want to increase Table B beyond the current segment boundary. </p>
	<p>		<p>
	<var>INCREASE</var> cannot be used for Table B in a hashed ~~organisation~~ file ( FILEORG = X'08' ).</p></td></tr>		<var>INCREASE</var> cannot be used for Table B in a hashed organization file (FILEORG = X'08').</p></td></tr>

	<tr><th>INCREASE TABLED<br/>INCREASE TABLEE or<br/>INCREASE TABLEX</th>		<tr><th>INCREASE TABLED<br/>INCREASE TABLEE or<br/>INCREASE TABLEX</th>

DmeWiccan: Automatically generated page update

2014-05-09T22:45:53Z

Automatically generated page update

← Older revision		Revision as of 22:45, 9 May 2014
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	<!-- end of toclimit div -->		<!-- end of toclimit div -->

	[[Category:~~File management~~]]		[[Category:Model 204 files]]

JAL: minor cleanup

2014-02-26T00:04:04Z

minor cleanup

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JAL at 00:53, 1 February 2014

2014-02-01T00:53:22Z

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JAL: more conversion cleanup

2014-01-31T23:42:21Z

more conversion cleanup

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ELowell at 21:20, 12 December 2013

2013-12-12T21:20:31Z

← Older revision		Revision as of 21:20, 12 December 2013
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	==Overview of capabilities==		==Overview of capabilities==

	Because of the hashed nature of Tables A and C, these tables can only be changed with the [[CREATE command: File\|CREATE command]] during a [[File ~~Reorganization~~ and ~~Table Compaction~~\|file reorganization]].		Because of the hashed nature of Tables A and C, these tables can only be changed with the [[CREATE command: File\|CREATE command]] during a [[File reorganization and table compaction\|file reorganization]].

	The other tables may be modified using the [[INCREASE command\|INCREASE]] and [[DECREASE command]], as follows:		The other tables may be modified using the [[INCREASE command\|INCREASE]] and [[DECREASE command]], as follows: