Managing file groups - Revision history

JAL: /* Procedure groups in APSYs */ link repair

2017-09-18T22:20:03Z

Procedure groups in APSYs: link repair

← Older revision		Revision as of 22:20, 18 September 2017
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	In your application design, you may have large amounts of code that is identical in multiple APSYs, but you may require different global settings between the APSYs. Since at compile time, procedure files are searched in the order they appear in the group, you can set different "first" procedure files, each followed by the same code base. </p>		In your application design, you may have large amounts of code that is identical in multiple APSYs, but you may require different global settings between the APSYs. Since at compile time, procedure files are searched in the order they appear in the group, you can set different "first" procedure files, each followed by the same code base. </p>
	<p>		<p>
	See ~~"Overview of the Subsystem Management facility" in the <var class="book">~~[~~http://docs.rocketsoftware.com/nxt/gateway.dll/RKBnew556/model%20204/v7.4/m204_v7r4_system_manager.pdf Rocket Model 204~~ System ~~Managers Guide~~]~~</var>~~ for more information about APSYs.</p>		See [[System requirements for Application Subsystems]] for more information about APSYs.</p>

	===Using a group to postpone a file reorganization===		===Using a group to postpone a file reorganization===

Dme: /* Files with large numbers of records */

2017-02-28T20:52:21Z

Files with large numbers of records

← Older revision		Revision as of 20:52, 28 February 2017
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	A single Model 204 file may only contain 16.7 million record slots. As applications grow, this limit may not be enough.</p>		A single Model 204 file may only contain 16.7 million record slots. As applications grow, this limit may not be enough.</p>
	<p>		<p>
	Defining a permanent file group enables support of much larger sets of data: a file group can have as many as 256 files.</p>		Defining a permanent file group enables support of much larger sets of data: a file group can have as many as 256 files.<!--Tested: GROUP001.DME.QA--></p>
	<p>		<p>
	Normally, if you take this approach, you do not randomly place the records anywhere in the group, but rather you partition the files based on some attribute. For example, you might use the Social Security number to decide in which file in a group to place a particular record. </p>		Normally, if you take this approach, you do not randomly place the records anywhere in the group, but rather you partition the files based on some attribute. For example, you might use the Social Security number to decide in which file in a group to place a particular record. </p>

DCameron: /* Files with large numbers of records */

2017-02-28T15:24:57Z

Files with large numbers of records

← Older revision		Revision as of 15:24, 28 February 2017
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	A single Model 204 file may only contain 16.7 million record slots. As applications grow, this limit may not be enough.</p>		A single Model 204 file may only contain 16.7 million record slots. As applications grow, this limit may not be enough.</p>
	<p>		<p>
	Defining a permanent file group enables support of much larger sets of data: a file group can have as many as ~~254~~ files.</p>		Defining a permanent file group enables support of much larger sets of data: a file group can have as many as 256 files.</p>
	<p>		<p>
	Normally, if you take this approach, you do not randomly place the records anywhere in the group, but rather you partition the files based on some attribute. For example, you might use the Social Security number to decide in which file in a group to place a particular record. </p>		Normally, if you take this approach, you do not randomly place the records anywhere in the group, but rather you partition the files based on some attribute. For example, you might use the Social Security number to decide in which file in a group to place a particular record. </p>

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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	</p>		</p>

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

JAL: more conversion cleanup

2014-02-26T02:18:53Z

more conversion cleanup

Show changes

JAL at 20:44, 2 January 2014

2014-01-02T20:44:14Z

← Older revision		Revision as of 20:44, 2 January 2014
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	<p>But even files where you do not expect to hit the record limit might benefit from partitioning. If you were, for example, to most commonly read data for a particular year, you would probably find that placing all the records for a year in different files would perform better than putting all of the records in a single file and indexing the year for easy access.</p>		<p>But even files where you do not expect to hit the record limit might benefit from partitioning. If you were, for example, to most commonly read data for a particular year, you would probably find that placing all the records for a year in different files would perform better than putting all of the records in a single file and indexing the year for easy access.</p>

	<p>See [[Files, ~~Groups~~, and ~~Reference Context~~#IN GROUP MEMBER clause\|IN GROUP MEMBER clause]] for more information.</p>		<p>See [[Files, groups, and reference context#IN GROUP MEMBER clause\|IN GROUP MEMBER clause]] for more information.</p>

	=== Procedure groups in APSYs ===		=== Procedure groups in APSYs ===

Admin: Admin moved page Managing File Groups to Managing file groups without leaving a redirect

2013-12-11T23:16:18Z

Admin moved page Managing File Groups to Managing file groups without leaving a redirect

← Older revision	Revision as of 23:16, 11 December 2013
(No difference)

JAL at 00:16, 12 September 2013

2013-09-12T00:16:45Z

← Older revision		Revision as of 00:16, 12 September 2013
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	* Temporary groups, and		* Temporary groups, and
	* Ad-hoc groups		* Ad-hoc groups



	== Permanent, Temporary and Ad-hoc Groups ==		== Permanent, Temporary and Ad-hoc Groups ==
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	FROM {filename [AT location] [(OPTIONAL) \| (MANDATORY)]} ,... [PARAMETER parameter[=value] [PARAMETER parameter[=value]]...		FROM {filename [AT location] [(OPTIONAL) \| (MANDATORY)]} ,... [PARAMETER parameter[=value] [PARAMETER parameter[=value]]...

	.		.

	.		.

	.		.

	END		END
	</p>		</p>
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	</td>		</td>
	</tr>		</tr>
	<tr>
	<td>Temporary</td>		<tr><td>Temporary</td>
	<td>		<td><p>By an individual user with the CREATE command and can be referenced only by that user. </p>
	<p>By an individual user with the CREATE command and can be referenced only by that user. </p>
	<p>Temporary group names exist only during the current login session and are deleted automatically when you log out, unless you delete them during the session. </p>		<p>Temporary group names exist only during the current login session and are deleted automatically when you log out, unless you delete them during the session. </p>
	<p>Use the following syntax to create a temporary group:</p>		<p>Use the following syntax to create a temporary group:</p>
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	</td>		</td>
	</tr>		</tr>

	<tr>		<tr>
	<td>Ad hoc</td>		<td>Ad hoc</td>
	<td>		<td><p>Within a User Language request by prefacing a statement with the clause: </p>
	<p>Within a User Language request by prefacing a statement with the clause: </p>
	<p class="code">IN <var class="term">file1</var>, <var class="term">file2</var> [,<var class="term">file3</var> ...]		<p class="code">IN <var class="term">file1</var>, <var class="term">file2</var> [,<var class="term">file3</var> ...]
	</p>		</p>
	<p>Ad hoc groups have no name and exist only for the current request. They allow record retrieval from many files at once without defining a group in advance. As in any IN clause, all of the files in an ad hoc group must be opened before the group is mentioned. For more information, see the description of Ad hoc groups in the <var>Rocket Model 204 User Language Manual</var>.</p>		<p>Ad hoc groups have no name and exist only for the current request. They allow record retrieval from many files at once without defining a group in advance. As in any IN clause, all of the files in an ad hoc group must be opened before the group is mentioned. For more information, see the description of Ad hoc groups in the <var>Rocket Model 204 User Language Manual</var>.</p></td></tr>
	</td>
	</tr>
	</table>		</table>





	== Using Groups ==		== Using Groups ==

	<p>There are a number of reasons why a file manager might set up file groups:</p>		<p>There are a number of reasons why a file manager might set up file groups:</p>

JAL at 00:14, 12 September 2013

2013-09-12T00:14:13Z

← Older revision		Revision as of 00:14, 12 September 2013
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	== Permanent, Temporary and Ad-hoc Groups ==		== Permanent, Temporary and Ad-hoc Groups ==


	===CREATE GROUP command and the types of groups ===		===CREATE GROUP command and the types of groups ===
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	<p>You may, in your application design, have large amounts of code identical in multiple APSYs, but you may require different global setting between the APSYs. Because, at compile time, procedure files are searched in the order they appear in the group. you can put different 'first' procedure files, each followed by the same code base. </p>		<p>You may, in your application design, have large amounts of code identical in multiple APSYs, but you may require different global setting between the APSYs. Because, at compile time, procedure files are searched in the order they appear in the group. you can put different 'first' procedure files, each followed by the same code base. </p>

	<p>See "Overview of the Subsystem Management facility" in [http://~~www~~.rocketsoftware.com/~~m204~~/~~products~~/~~index~~/~~documentation~~/~~v7r4/M204-System-Mgr/view~~ The Model 204 System Managers Guide] for more information on APSYs.</p>		<p>See "Overview of the Subsystem Management facility" in [http://docs.rocketsoftware.com/nxt/gateway.dll/RKB6/system%20%26%20file%20management/m204_v7r4_system_manager.pdf The Model 204 System Managers Guide] for more information on APSYs.</p>

	=== Postponing reorganizations with Groups ===		=== Postponing reorganizations with Groups ===
			<p class="note">'''Note:''' the following technique cannot be used if there are references in your code to Internal Record Numbers (IRNs). IRNs (without also specifying a group member) cannot be used against group files.</p>
	<p>Note: the following technique cannot be used if there are references in your code to Internal Record Numbers (IRNs). IRNs (without also specifying a group member~~, can not~~ be used against group files)</p>

	* File X is almost full		* File X is almost full
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	END		END
	</p>		</p>






	[[Category:File management]]		[[Category:File management]]

JDamon: /* Files with large numbers of record */

2013-05-23T19:35:38Z

Files with large numbers of record

← Older revision		Revision as of 19:35, 23 May 2013
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	<p>A single Model 204 file may only contain 16.7 million record slots. As applications grow, this limit may not be enough.</p>		<p>A single Model 204 file may only contain 16.7 million record slots. As applications grow, this limit may not be enough.</p>

	<p>~~Define~~ a permanent file group can support much larger sets of data: there can be up to 254 files in a file group.</p>		<p>Defining a permanent file group can support much larger sets of data: there can be up to 254 files in a file group.</p>

	<p>Normally, if you take this approach, you would not randomly place the records anywhere in the group, but rather you would partition the files based on some attribute. For example, you may use the Social Security Number to decide which file in a group to place a particular record in. '''Hint:''' because some identifiers have hidden meanings (the high order digits of the Social Security Numbers used to identify the region where the application was made, for example), often the low order digits make a better randomizer.</p>		<p>Normally, if you take this approach, you would not randomly place the records anywhere in the group, but rather you would partition the files based on some attribute. For example, you may use the Social Security Number to decide which file in a group to place a particular record in. '''Hint:''' because some identifiers have hidden meanings (the high order digits of the Social Security Numbers used to identify the region where the application was made, for example), often the low order digits make a better randomizer.</p>

	=== Partitioning for performance ===		=== Partitioning for performance ===