A method for joining two value-ordered primary index tables T1 and T2 in
response to a join command is disclosed. T1 and T2 each include rows. T1
and T2 each have a first row. A subset of the rows of T1 is loaded into
memory. The subset is consecutive and includes the first row of T1. The
first row of T2 is loaded into memory. The loaded row of T2 is compared
to the loaded rows of T1. If there is a match, it is output. If there is
not a match, that lack is recorded. A next consecutive row of T2 is
loaded into memory. The comparison, output, recording, and loading of
consecutive T2 rows is repeated. New rows of T1 are loaded into memory.
The new rows are consecutive and are consecutive with the previously
loaded rows of T1. The combination of a repetition of comparison, output,
recording, and loading of consecutive T2 rows with loading new rows of T1
into memory is repeated.