Syntax

$objects.preload(
    attributes: [...], 
    fun: list -> ...
)

Description

Loads the specified attributes of a given set of objects from the database with an optimized bulk load and keeps the values in the cache until the given function has been evaluated.

Parameters

name	Type	Type Description	Mandatory	Default
objects	Set of objects	The objects whose attributes are to be loaded.	Yes	-
attributes	Set of attributes and references	Attributes that are to be loaded on all given objects.	Yes	-
fun	Function	Function that is evaluated on the input set after the load operation.	yes	-

Return value

The value calculated by the given function is returned.

Explanation

If the value of an object is queried during a function evaluation, it is possible that the corresponding value has not yet been loaded from the database. In this case, the value is loaded on access. If an operation is executed on many objects, this can lead to a large number of database accesses, which slow down the evaluation. The preload operation can be used to ensure that the load operation is optimized on a large number of objects in advance so that the function evaluation can then take place quickly on the temporarily stored values.