General parameters > Chapter Supervisor > Parameter NBDERLUS (Last read lines) 

This parameter is used to define the maximum number of lines in the "Last read" left list, when it is present in the object.

Level of localization / Global variable

The parameter is defined at the level User.Belongs to Module SUP (Supervisor) and to Group SEL (Selection Listing),in which the following parameters can also be found :

The global variable GNBDERNIER is associated to it.

Linked parameters

The following parameters are linked to the parameter NBDERLUS  :

Supervisor

 NBRCHOOSE (defined at level User) : Default elements of selection

Functions concerned

All the functions likely to use selection lists of the last read are involved (that is to say all of the object functions).

Comments

It should be noted that in versions 130 and 120, this parameter is materialized by a field in the user record.

Performance optimization

The loading time of the lists (left lists, selection, last read) which, in some cases, is necessary for each access to an object, is proportional to the number of elements read, and it consumes resources, both at the level of the processing server and the data server.

In a situation where there is a large number of users, and moreover using complex filtering rules on the data, these queries can have a significant impact on the general perfomances of the system.

Since this parameter allows the number of lines read to be restricted, while still allowing the next lines to be read by means of a simple pagination, it is recommended to give this parameter a reasonable value (for instance, the content of a screen page), although it is possible, in some particular cases, to go well beyond (like several thousand lines).