A list of database objects.
A list of slot names, or
The class of the objects, or
A non-negative integer, or
This is an optimization function which can improve the efficiency of an application by reducing the number of queries of the database. For each slot, it queries the database using the data from all the objects, and then assigns the appropriate value to each object.
objects is a list of database objects. If class-name is non-nil, then all the database objects are of this class. If class-name is
nil, then all the database objects are of the class of the first database object in the list objects.
max-len, if non-nil, is a maximum number of objects from which to use data in a single query. If the length of the list objects is greater than max-len then
update-objects-joins performs multiple queries using the data from no more than max-len objects in each query. This is useful if the DBMS may reject large queries, but it will increase the number of queries and hence reduce overall performance to some extent. The default value of max-len is the value of the variable *default-update-objects-max-len*.
LispWorks User Guide and Reference Manual - 20 Sep 2017