Abstract: A garbage collector that employs the train algorithm determines whether futile collections have been occurring or the number of trains has reached a maximum. When either situation occurs, it merges a plurality of existing trains into a single new train. If the collector detects futile collection, it merges the oldest train with one of the other trains. If the number of trains reaches a maximum, the collection so merges trains that the next train addition will not cause the number of trains to exceed the maximum.

Abstract: A software module referred to as a content manager is provided for loading and maintaining a variety of data and associated metadata in a computer database. The data may be loaded in the form of individual documents that support business preparation or sales presentations where only one copy of each document is stored in the database. The metadata may be loaded in the form of attributes of the documents. A table of users may also be loaded in the database including a geographic or business division for each user. A role is assigned to the user, thereby granting access privileges to certain views of the database. An online user interface software module is also provided for remote access to the documents. Searches may be conducted by a variety of attributes. Documents may be associated into visual presentations or multiple presentations merged into one presentation. Three types of presentations private, shared, and global are supported.

Abstract: A client submits a subscription to a database specifying selected data within a data set. A subscription plan is generated based on the subscription. A query is submitted to the database changing selected data within the data set. A query plan is generated based on the query. The subscription is matched to the query based on the data set, and the query plan is supplemented with the subscription plan to generate a notification of the change to the client.