Faster Display of Documents

Documents whose underlying form uses the @DbLookup or @DbColumn functions often take a comparatively long time to display when opened in the Notes Client — even when the documents are only viewed in "read mode".

Why is that?

This is because certain computed or editable fields execute their formulas even when a document is opened in read mode.

You cannot prevent the field formulas from executing, but the "lookup functions" don't always need to be run.

What can you do as a developer?

In the relevant field formulas, the "lookup functions" should not be executed when a document is only being opened for display on screen in the Notes Client. The @If function is the key here.

1. Example: Keyword list formula with @DbColumn


@DbColumn(class:cache; server:database; view; columnNumber)

should be changed to:


@If( !@IsNewDoc & @IsDocBeingLoaded;
        @Return("");
        @DbColumn(class:cache; server:database; view; columnNumber)
)

2. Example: Keyword list formula with @DbLookup


@DbLookup(class:cache; server:database; view; key; columnNumber; keywords)

should be changed to:


@If( !@IsNewDoc & @IsDocBeingLoaded;
        @Return("");
        @DbLookup(class:cache; server:database; view; key; columnNumber; keywords)
)

Note on the @Return function

From the HCL Online Help:

Immediately stops the execution of a formula and returns the specified value. This is useful when you only want the remainder of the formula to be executed only if certain conditions are True.
@Return (Formula Language)

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