The Resident property allows you to determine whether the table should be treated as a resident table, and if so, when the table is loaded. The valid values for this property are:
No (the default) – The table is not treated as a resident table. It closes as soon as the task that uses it closes.
Immediate – The table is a resident table. It is loaded when the application is loaded and remains open until the application closes. Tables that are used by all the users throughout the application should be loaded immediately when the application is started.
On Demand – The table is a resident table. It is loaded the first time a program opens it, and remains open until the application closes. Tables that may be used very often but only in a particular place in the application should be loaded On Demand.
Immediate and on Client – The table is a resident table, is loaded directly from the browser or Rich Client, and is kept locally on the client side. The effect of a table set with this option, is that a recompute of a Link operation of that table is done locally. The table will be fetched to the client when the link is re-evaluated.
The Resident Table facility is based on the same assumption as the Magic xpa cache, that is, that certain data in an application will be used more than once. The Resident Table facility is an additional tool that can be used by the developer to enhance system performance by reducing disk I/O, and in the case of Client/Server configurations, reducing network traffic. Magic xpa will read the contents of all tables defined as resident into memory, according to the setting of the Resident property.
Preloading a table means that its data will be read and stored in the client’s memory, and all access will be through the loaded data in memory. The data can be preloaded upon opening the application, or upon opening the table, depending on the parameters specified in the Data Source Properties dialog box of the running tasks. The resident table will be cleared upon the closing of the application. It is recommended to use the Resident option with small tables, because loading tables into the client's memory reduces the client's free memory.
Limitations: This property is not supported for local data sources.
See also:
How Do I Fetch Data from a Database Table a Single Time for the Whole Application?
How Do I Minimize Database Access for Read-only Data?
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