The converter is a cache. In the converter, the database system keeps all information about which logical data pages are saved to which physical positions. When the database system fails to find a data page in the data cache, it searches for the logical position of the data page in the converter and uses this to calculate the physical position of the data page in the data volume.
The converter has the structure of a B* tree and is based on the standby memory concept. This means that the last saved database state is stored in standby pages. When pages are changed, the database system first creates copies. Only when the changed pages have been saved does it release the standby pages to be overwritten.
Pages are never displaced from the converter. If necessary, the database system moves additional pages from the I/O buffer cache to the converter. You are, therefore, unable to configure the size of the converter explicitly.
At each savepoint, the converter is frozen briefly, and the version created is given a version number. This number increases with each subsequent savepoint.
The converter is used jointly by all simultaneously active users.