Alex: Expand: SOUL access model, RELEASE IMAGINE RECORDS, IMAGINE EXTRACT/SYNC/ENDSYNC + DISPLAY IMAGINESYNC, restrictions, See also, category

2026-08-27T01:42:19Z

Expand: SOUL access model, RELEASE IMAGINE RECORDS, IMAGINE EXTRACT/SYNC/ENDSYNC + DISPLAY IMAGINESYNC, restrictions, See also, category

← Older revision		Revision as of 01:42, 27 August 2026
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	Once this is done, any reference to <var>SOMEFILE</var> in a<var class="product">Model 204</var> application (including in file groups) would access the data from <var class="product">Imagine</var> via the <var>IMAGINET</var> port. Note that a single <var class="product">Model 204</var> file can corresponding to many <var class="product">Imagine</var> files if record types are used.		Once this is done, any reference to <var>SOMEFILE</var> in a<var class="product">Model 204</var> application (including in file groups) would access the data from <var class="product">Imagine</var> via the <var>IMAGINET</var> port. Note that a single <var class="product">Model 204</var> file can corresponding to many <var class="product">Imagine</var> files if record types are used.

			==Accessing Imagine files from SOUL==
			No application changes are required to read or update a Transparency file. Ordinary SOUL statements such as <var>FIND</var>, <var>FOR EACH RECORD</var>, <var>FIND AND PRINT COUNT</var>, <var>STORE RECORD</var>, <var>CHANGE</var>, <var>ADD</var>, and <var>DELETE</var> operate on a Transparency file exactly as they do on a native <var class="product">Model 204</var> file. <var class="product">Model 204</var> transparently sends the corresponding requests to the <var class="product">Imagine</var> broker over the <var>IMAGINET</var> port and returns the results to the application.

			To reduce broker round trips, <var class="product">Model 204</var> caches the results of Transparency finds and prefetches records from find result sets. Cached finds are automatically deoptimized and revalidated when records they reference are changed, so applications always see a consistent view of the data.

			===Releasing held records===
			Records retrieved from <var class="product">Imagine</var> are held on a Transparency thread for the duration of the request. The <var>RELEASE IMAGINE RECORDS</var> statement releases those held records and frees the Transparency thread. Specify the <var>CLEARLISTS</var> option to also clear any <var class="term">$lists</var> and <var class="term">StringLists</var> that reference the released records:
			<p class="pre">RELEASE IMAGINE RECORDS CLEARLISTS
			</p>

			==Populating and synchronizing Imagine files==
			Before a <var class="product">Model 204</var> file can be switched to Transparency mode, its data must be loaded into <var class="product">Imagine</var>. The <var>[[IMAGINE command]]</var> extracts the data from an existing <var class="product">Model 204</var> file and loads it into <var class="product">Imagine</var>:
			<ul>
			<li><var>IMAGINE EXTRACT</var> copies the file's records to <var class="product">Imagine</var> as a one-time operation.</li>
			<li><var>IMAGINE SYNC</var> copies the records and then keeps <var class="product">Model 204</var> and <var class="product">Imagine</var> in sync, so that subsequent updates are also applied to <var class="product">Imagine</var>. This makes it feasible to switch a file to Transparency mode with a minimal outage.</li>
			<li><var>IMAGINE ENDSYNC</var> ends a SYNC or EXTRACT for the file.</li>
			</ul>
			The <var>[[DISPLAY IMAGINESYNC command]]</var> lists all files that are currently in <var>IMAGINE SYNC</var> mode.

			==Restrictions==
			The following operations are not supported against an <var class="product">Imagine</var> Transparency file:
			<ul>
			<li><var>DEFINE FIELD</var> — field definitions are determined by the underlying <var class="product">Imagine</var> file and cannot be changed from <var class="product">Model 204</var>.</li>
			<li><var>FOR EACH RECORD IN ORDER</var> — ordered retrieval is not supported for Transparency files.</li>
			</ul>

			==See also==
			<ul>
			<li><var>[[IMAGINE command]]</var></li>
			<li><var>[[DISPLAY IMAGINESYNC command]]</var></li>
			<li><var>[[JANUS DEFINE]]</var> (the <var>IMAGINET</var> port type)</li>
			<li><var>[[DEFINE DATASET command]]</var> (allocating a file <var>WITH IMAGINE</var>)</li>
			<li>[[Release notes for Model 204 version 8.0#Imagine Transparency support\|Model 204 version 8.0 release notes]]</li>
			</ul>

			[[Category:File management]]

Alex: Created page with "The `Imagine Transparency` facility allows `Model 204` programs to access files stored in the `Imagine` database as if they were local files. This facility is available in `Model 204` Version 8.0 and later. While a fair amount of setup is required to define and populate the `Imagine` files being accessed in Transparency mode, and create `Imagi..."`

2024-07-31T21:15:04Z

Created page with "The <var class="product">Imagine Transparency</var> facility allows <var class="product">Model 204</var> programs to access files stored in the <var class="product">Imagine</var> database as if they were local files. This facility is available in <var class="product">Model 204</var> Version 8.0 and later. While a fair amount of setup is required to define and populate the <var class="product">Imagine</var> files being accessed in Transparency mode, and create <var>Imagi..."

New page

The <var class="product">Imagine Transparency</var> facility allows <var class="product">Model 204</var> programs to access files stored in the <var class="product">Imagine</var> database as if they were local files. This facility is available in <var class="product">Model 204</var> Version 8.0 and later.

While a fair amount of setup is required to define and populate the <var class="product">Imagine</var> files being accessed in Transparency mode, and create <var>Imagine</var> broker processes to provide <var class="product">Model 204</var> access to the <var class="product">Imagine</var> files, very little setup is required on <var class="product">Model 204</var>.

First, an [[JANUS_DEFINE#IMAGINET|IMAGINET]] port must be defined in an Online that would be using <var>Transparency Mode</var>. The number of connections required is the maximum number of threads simultaneously accessing <var class="product">Imagine</var> files in the Online. The total number of threads in the Online is, of course, an upper bound for this number.

Then, each <var class="product">Model 204</var> file hosted on <var class="product">Imagine</var> needs to [[DEFINE DATASET command#IMAGINE|be allocated]] as an <var class="product">Imagine</var> file. For example:
<p class="pre">ALLOCATE SOMEFILE WITH IMAGINE
</p>
Once this is done, any reference to <var>SOMEFILE</var> in a<var class="product">Model 204</var> application (including in file groups) would access the data from <var class="product">Imagine</var> via the <var>IMAGINET</var> port. Note that a single <var class="product">Model 204</var> file can corresponding to many <var class="product">Imagine</var> files if record types are used.

Imagine Transparency - Revision history

Alex: Expand: SOUL access model, RELEASE IMAGINE RECORDS, IMAGINE EXTRACT/SYNC/ENDSYNC + DISPLAY IMAGINESYNC, restrictions, See also, category