BLDREUSE command - Revision history

DCameron: /* Planning to run a BLDREUSE command */

2019-02-06T15:08:48Z

Planning to run a BLDREUSE command

← Older revision		Revision as of 15:08, 6 February 2019
Line 41:		Line 41:
	<p>Plan to run the BLDREUSE NEW command when reuse queue errors are detected or when the reuse queue has too many unusable pages. The BLEREUSE NEW command requires an exclusive access to the file.</p>		<p>Plan to run the BLDREUSE NEW command when reuse queue errors are detected or when the reuse queue has too many unusable pages. The BLEREUSE NEW command requires an exclusive access to the file.</p>
	<p>The BLDREUSE NEW command can initialize and rebuild a new reuse queue based on a check of all Table B pages. All ineligible pages are gone and all eligible pages are added. So you can use a BLDREUSE NEW command to completely rebuild a reuse queue, if errors indicate the queue has a problem.</p>		<p>The BLDREUSE NEW command can initialize and rebuild a new reuse queue based on a check of all Table B pages. All ineligible pages are gone and all eligible pages are added. So you can use a BLDREUSE NEW command to completely rebuild a reuse queue, if errors indicate the queue has a problem.</p>
	<p>Plan to run a BLDREUSE FROM and/or TO command when there is a possibility of finding eligible pages for reuse or run the command periodically on files with high update transaction activity to find pages not placed on the reuse queue because of constraint conditions. Also, changes to BRESERVE and/or BREUSE parameters can result in pages becoming eligible for reuse, but not put on the reuse queue. </p>		<p>Plan to run a BLDREUSE FROM and/or TO command when there is a possibility of finding eligible pages for reuse or run the command periodically on files with high update transaction activity to find pages not placed on the reuse queue because of constraint conditions. Also, changes to <var>[[BRESERVE_parameter\|BRESERVE]]</var> and/or <var>[[BREUSE_parameter\|BREUSE]]</var> parameters can result in pages becoming eligible for reuse, but not put on the reuse queue. </p>
	<p>BLDREUSE FROM and/or TO command cannot remove ineligible pages from the reuse queue. For example, a page that is currently on the reuse queue, but is no longer eligible to be there, is not dropped by BLDREUSE FROM and/or TO processing. </p>		<p>BLDREUSE FROM and/or TO command cannot remove ineligible pages from the reuse queue. For example, a page that is currently on the reuse queue, but is no longer eligible to be there, is not dropped by BLDREUSE FROM and/or TO processing. </p>

	====Delaying file reorganization====		====Delaying file reorganization====
	<p>When a file becomes full due to a small or empty reuse queue, you can avoid a file reorganization by doing the following: </p>		<p>When a file becomes full due to a small or empty reuse queue, you can avoid a file reorganization by doing the following: </p>

DCameron: /* Syntax */

2019-02-06T15:06:11Z

Syntax

← Older revision		Revision as of 15:06, 6 February 2019
Line 15:		Line 15:
	<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when <var>[[NUSERS_parameter\|NUSERS]]</var>=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>		<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when <var>[[NUSERS_parameter\|NUSERS]]</var>=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>
	<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>		<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>
	<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (<var>[[BHIGHPG_parameter\|BHIGHPG</var> and/or <var>[[XHIGHPG_parameter\|XHIGHPG]]</var>).</p>		<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (<var>[[BHIGHPG_parameter\|BHIGHPG]]</var> and/or <var>[[XHIGHPG_parameter\|XHIGHPG]]</var>).</p>
	<p><var>TABLEB, TABLEX</var> or <var>ALL</var> specify the table you want scanned. <var>ALL</var> specifies both tables. </p>		<p><var>TABLEB, TABLEX</var> or <var>ALL</var> specify the table you want scanned. <var>ALL</var> specifies both tables. </p>

DCameron: /* Syntax */

2019-02-06T15:05:48Z

Syntax

← Older revision		Revision as of 15:05, 6 February 2019
Line 15:		Line 15:
	<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when <var>[[NUSERS_parameter\|NUSERS]]</var>=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>		<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when <var>[[NUSERS_parameter\|NUSERS]]</var>=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>
	<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>		<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>
	<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (BHIGHPG and/or XHIGHPG).</p>		<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (<var>[[BHIGHPG_parameter\|BHIGHPG</var> and/or <var>[[XHIGHPG_parameter\|XHIGHPG]]</var>).</p>
	<p><var>TABLEB, TABLEX</var> or <var>ALL</var> specify the table you want scanned. <var>ALL</var> specifies both tables. </p>		<p><var>TABLEB, TABLEX</var> or <var>ALL</var> specify the table you want scanned. <var>ALL</var> specifies both tables. </p>

DCameron: /* Syntax */

2019-02-06T15:04:12Z

Syntax

← Older revision		Revision as of 15:04, 6 February 2019
Line 13:		Line 13:
	[TABLEB \| TABLEX \| ALL]]</p>		[TABLEB \| TABLEX \| ALL]]</p>
	<p>where</p>		<p>where</p>
	<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when NUSERS=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>		<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when <var>[[NUSERS_parameter\|NUSERS]]</var>=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>
	<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>		<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>
	<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (BHIGHPG and/or XHIGHPG).</p>		<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (BHIGHPG and/or XHIGHPG).</p>

DCameron: /* Summary */

2019-02-06T15:02:16Z

Summary

← Older revision		Revision as of 15:02, 6 February 2019
Line 4:		Line 4:
	<dd>File manager		<dd>File manager
	<dt>Function		<dt>Function
	<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the [[Table_B_(File_architecture)\|Table B]] and/or [[Table_X_(File_architecture)\|Table X]] pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.		<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the [[Table_B_(File_architecture)\|Table B]] and/or [[Table_X_(File_architecture)\|Table X]] pages of an open, current or specified, file and add pages that are not on the [[File_design#Maintaining_the_reuse_queue\|reuse queue]], but are eligible for the queue.
	</dl>		</dl>

DCameron: /* Summary */

2019-02-06T14:59:14Z

Summary

← Older revision		Revision as of 14:59, 6 February 2019
Line 4:		Line 4:
	<dd>File manager		<dd>File manager
	<dt>Function		<dt>Function
	<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the [[Table_B_(File_architecture)\|Table B]] and/or Table X pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.		<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the [[Table_B_(File_architecture)\|Table B]] and/or [[Table_X_(File_architecture)\|Table X]] pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.
	</dl>		</dl>

DCameron: /* Summary */

2019-02-06T14:58:25Z

Summary

← Older revision		Revision as of 14:58, 6 February 2019
Line 4:		Line 4:
	<dd>File manager		<dd>File manager
	<dt>Function		<dt>Function
	<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the Table B and/or Table X pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.		<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the [[Table_B_(File_architecture)\|Table B]] and/or Table X pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.
	</dl>		</dl>

DCameron: /* Summary */

2019-02-06T14:57:35Z

Summary

← Older revision		Revision as of 14:57, 6 February 2019
Line 4:		Line 4:
	<dd>File manager		<dd>File manager
	<dt>Function		<dt>Function
	<dd>For unordered files to scan the Table B and/or Table X pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.		<dd>For [[File_design#Unordered_files_.28X.2720.27.29\|unordered]] files to scan the Table B and/or Table X pages of an open, current or specified, file and add pages that are not on the reuse queue, but are eligible for the queue.
	</dl>		</dl>

	==Syntax==		==Syntax==
	<p class="syntax">BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]][TABLEB \| TABLEX \| ALL]</p>		<p class="syntax">BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]][TABLEB \| TABLEX \| ALL]</p>

ELowell: minor syntax formatting

2017-03-31T15:49:34Z

minor syntax formatting

← Older revision		Revision as of 15:49, 31 March 2017
Line 7:		Line 7:
	</dl>		</dl>
	==Syntax==		==Syntax==
	<p class="syntax">BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]][TABLEB \| TABLEX \| ALL]		<p class="syntax">BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]][TABLEB \| TABLEX \| ALL]</p>
	or		<p>or</p>
	IN filename BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]]		<p class="syntax">IN filename BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]]
	[TABLEB \| TABLEX \| ALL]]		[TABLEB \| TABLEX \| ALL]]</p>
	</p>
	<p>where</p>		<p>where</p>
	<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when NUSERS=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>		<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when NUSERS=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>

ELowell: /* Syntax */

2013-07-16T18:56:24Z

Syntax

← Older revision		Revision as of 18:56, 16 July 2013
Line 7:		Line 7:
	</dl>		</dl>
	==Syntax==		==Syntax==
	<p class="syntax">BLDREUSE [NEW \| [FROM nn][TO nn]][TABLEB \| TABLEX \| ALL]		<p class="syntax">BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]][TABLEB \| TABLEX \| ALL]
	or		or
	IN filename BLDREUSE [NEW \| [FROM nn][TO nn]]		IN filename BLDREUSE [NEW \| [FROM <var class="term">nn</var>][TO <var class="term">nn</var>]]
	[TABLEB \| TABLEX \| ALL]]		[TABLEB \| TABLEX \| ALL]]
	</p>		</p>
	<p>where</p>		<p>where</p>
	<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when NUSERS=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>		<p><var>NEW</var> specifies building the reuse queue anew. For example, you would use NEW if the queue was broken or had too many unusable pages. The NEW parameter excludes the use of the FROM and/or TO parameters. Also, NEW can only be executed when NUSERS=1; in other words, in single-user mode only. NEW requires exclusive access to the file and completely rebuilds the reuse queue from scratch.</p>
	<p><var>FROM nn</var> indicates the starting table page number. The default is zero.</p>		<p><var>FROM</var> <var class="term">nn</var> indicates the starting table page number. The default is zero.</p>
	<p><var>TO nn</var> indicates the ending table page number. The default is the current highest active page number (BHIGHPG and/or XHIGHPG).</p>		<p><var>TO</var> <var class="term">nn</var> indicates the ending table page number. The default is the current highest active page number (BHIGHPG and/or XHIGHPG).</p>
	<p><var>TABLEB, TABLEX</var> or <var>ALL</var> specify the table you want scanned. ALL specifies both tables. </p>		<p><var>TABLEB, TABLEX</var> or <var>ALL</var> specify the table you want scanned. <var>ALL</var> specifies both tables. </p>

	==Usage==		==Usage==
	<p>The primary purpose of the BLDREUSE command is to maximize the usability of the pages on the reuse queue.</p>		<p>The primary purpose of the BLDREUSE command is to maximize the usability of the pages on the reuse queue.</p>