Tuning the hash index - Revision history

ELowell at 16:53, 12 May 2014

2014-05-12T16:53:09Z

← Older revision		Revision as of 16:53, 12 May 2014
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	To monitor Table C, use the <var>[[CRETRIES parameter\|CRETRIES]]</var> parameter and the <var>[[TABLEC command\|TABLEC]]</var> command. Their use is discussed below.		To monitor Table C, use the <var>[[CRETRIES parameter\|CRETRIES]]</var> parameter and the <var>[[TABLEC command\|TABLEC]]</var> command. Their use is discussed below.
	<p>		<p>
	See also [[Field design ~~(File management)~~#Indexing fields\|Indexing fields]] for more information on choosing the type of indexes for your fields.</p>		See also [[Field design#Indexing fields\|Indexing fields]] for more information on choosing the type of indexes for your fields.</p>

	==Using CRETRIES in monitoring==		==Using CRETRIES in monitoring==
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	A rough guideline for users concerned with access performance is to aim for 75 percent utilization. If space is the only constraint, you should be able to achieve 85 percent utilization. Remember that this figure varies depending on the characteristics of the data.</p>		A rough guideline for users concerned with access performance is to aim for 75 percent utilization. If space is the only constraint, you should be able to achieve 85 percent utilization. Remember that this figure varies depending on the characteristics of the data.</p>

	<p>Table C never can be 100 percent utilized. A Table C full condition may happen at any point after utilization reaches 85 percent. Because of this uncertainty, strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[Field design ~~(File management)~~#Indexing fields\|Indexing fields]] for more information.</p>		<p>Table C never can be 100 percent utilized. A Table C full condition may happen at any point after utilization reaches 85 percent. Because of this uncertainty, strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[Field design#Indexing fields\|Indexing fields]] for more information.</p>

	==Using the TABLEC command in monitoring==		==Using the TABLEC command in monitoring==

DmeWiccan: Automatically generated page update

2014-05-09T22:45:57Z

Automatically generated page update

← Older revision		Revision as of 22:45, 9 May 2014
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	THE NUMBER OF PAGES WITH SPILLS IS 2</p>		THE NUMBER OF PAGES WITH SPILLS IS 2</p>

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

Admin: /* Using CRETRIES in monitoring */

2014-03-14T01:33:31Z

Using CRETRIES in monitoring

← Older revision		Revision as of 01:33, 14 March 2014
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	similar to those in the following diagram. (This is from a small file with a <var>[[CSIZE parameter\|CSIZE]]</var> of 10.)</p>		similar to those in the following diagram. (This is from a small file with a <var>[[CSIZE parameter\|CSIZE]]</var> of 10.)</p>

			<p class="caption">Effect of page retries on Table C utilization</p>
	:::[[File:Table C Utilization.jpg]]		:::[[File:Table C Utilization.jpg]]

JAL at 23:55, 6 March 2014

2014-03-06T23:55:06Z

Show changes

Admin at 22:21, 18 December 2013

2013-12-18T22:21:35Z

← Older revision		Revision as of 22:21, 18 December 2013
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	=== Using the TABLEC command to detect overflows===		=== Using the TABLEC command to detect overflows===
	The TABLEC command reports on property entry overflows vs. number of		The TABLEC command reports on property entry overflows vs. number of
	pages with spills. As described in [[Table C (File ~~Architecture~~)\|the file architecture discussion]], Table C contains		pages with spills. As described in [[Table C (File architecture)\|the file architecture discussion]], Table C contains
	property entries and segment entries. </P>		property entries and segment entries. </P>

ELowell: /* Using CRETRIES in Monitoring */

2013-12-16T19:48:35Z

Using CRETRIES in Monitoring

← Older revision		Revision as of 19:48, 16 December 2013
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	utilization reaches 85 percent.</p>		utilization reaches 85 percent.</p>

	<p>Because of this uncertainty, strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[#Field ~~Design~~ (File ~~Management~~) Indexing ~~Fields~~\|Indexing ~~Fields~~]] for more information.</p>		<p>Because of this uncertainty, strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[Field design (File management)#Indexing fields\|Indexing fields]] for more information.</p>

	== Using the TABLEC command in Monitoring ==		== Using the TABLEC command in Monitoring ==

ELowell at 19:47, 16 December 2013

2013-12-16T19:47:39Z

← Older revision		Revision as of 19:47, 16 December 2013
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	To monitor Table C, use the [[CRETRIES parameter]] and the [[TABLEC command]]. Their use is discussed below.		To monitor Table C, use the [[CRETRIES parameter]] and the [[TABLEC command]]. Their use is discussed below.

	<p>See also [[Field ~~Design~~ (File ~~Management~~)#Indexing ~~Fields~~\|Indexing ~~Fields~~]] for more information on choosing the type of indexes for your fields.</p>		<p>See also [[Field design (File management)#Indexing fields\|Indexing fields]] for more information on choosing the type of indexes for your fields.</p>

	== Using CRETRIES in Monitoring ==		== Using CRETRIES in Monitoring ==

ELowell: /* Using CRETRIES in Monitoring */

2013-07-01T18:45:44Z

Using CRETRIES in Monitoring

← Older revision		Revision as of 18:45, 1 July 2013
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	<p>Although these figures vary from file to file, experiments have produced results		<p>Although these figures vary from file to file, experiments have produced results
	similar to those in the following diagram. (This from a small file with CSIZE = 10).</p>		similar to those in the following diagram. (This is from a small file with CSIZE = 10.)</p>

	:::[[File:Table C Utilization.jpg]]		:::[[File:Table C Utilization.jpg]]
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	utilization reaches 85 percent.</p>		utilization reaches 85 percent.</p>

	<p>Because of this uncertainty, ~~Rocket Software encourages users to~~ strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[#Field Design (File Management) Indexing Fields\|Indexing Fields]] for more information.</p>		<p>Because of this uncertainty, strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[#Field Design (File Management) Indexing Fields\|Indexing Fields]] for more information.</p>

	== Using the TABLEC command in Monitoring ==		== Using the TABLEC command in Monitoring ==

ELowell: /* Monitoring Table C */

2013-07-01T18:40:36Z

Monitoring Table C

← Older revision		Revision as of 18:40, 1 July 2013
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	==Monitoring Table C==		==Monitoring Table C==

	To monitor Table C, use the [[CRETRIES parameter]] and the [[TABLEC		To monitor Table C, use the [[CRETRIES parameter]] and the [[TABLEC command]]. Their use is discussed below.
	command]]. Their use is discussed below.

	<p>See also [[Field Design (File Management)#Indexing Fields\|Indexing Fields]] for more information on choosing the type of indexes for your fields.</p>		<p>See also [[Field Design (File Management)#Indexing Fields\|Indexing Fields]] for more information on choosing the type of indexes for your fields.</p>

ELowell: /* Using CRETRIES in Monitoring */

2013-07-01T18:38:29Z

Using CRETRIES in Monitoring

← Older revision		Revision as of 18:38, 1 July 2013
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	<p>See also [[Field Design (File Management)#Indexing Fields\|Indexing Fields]] for more information on choosing the type of indexes for your fields.</p>		<p>See also [[Field Design (File Management)#Indexing Fields\|Indexing Fields]] for more information on choosing the type of indexes for your fields.</p>

	== Using [[CRETRIES ~~parameter\|CRETRIES]]~~ in Monitoring ==		== Using CRETRIES in Monitoring ==

	~~<p>~~The ~~page retry statistic (the~~ CRETRIES parameter~~) is provided~~. ~~Each retry~~ indicates a slight degradation in indexed retrieval speeds. Far more significantly (given the limitations in ~~hoe~~ Table C may be increased), page retries are a signal that Table C is becoming crowded.~~</p>~~		The [[CRETRIES parameter]] provides the count of the total number of page retries while storing index entries in Table C. Retry indicates a slight degradation in indexed retrieval speeds. Far more significantly (given the limitations in how Table C may be increased), page retries are a signal that Table C is becoming crowded.

	<p>Although these figures vary from file to file, experiments have produced results		<p>Although these figures vary from file to file, experiments have produced results
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	<p>Because of this uncertainty, Rocket Software encourages users to strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[#Field Design (File Management) Indexing Fields\|Indexing Fields]] for more information.</p>		<p>Because of this uncertainty, Rocket Software encourages users to strongly consider the use of the Ordered Index as a replacement for the hashed index. This can be done without code changes. See [[#Field Design (File Management) Indexing Fields\|Indexing Fields]] for more information.</p>


	== Using the TABLEC command in Monitoring ==		== Using the TABLEC command in Monitoring ==