Performance on Ground Data Processing Systems on MAXI/ISS

MAXI, Monitor of All-sky X-ray Image, is an all-sky X-ray monitor on the International Space Station, ISS, beginning observation in 2008. Each second X-ray photon event data downloaded from the ISS are stored into a PostgreSQL database, and simultaneously processed to find an X-ray flare/burst in a nova search system. The database is the first photon event database, and will have more than 10 Giga records at the end of the mission. Thanks to high performance of the RDBMS, it takes about 5--10 min to produce X-ray event files for about 1,000 objects from 10 Mega records (∼1 day) data. This easily enables us to provide new data to the world every day or every orbital revolution ∼90 m. Here, we present the outline of the MAXI ground software systems, the performance on this huge photon event database, and the functionality of the nova search system.