Ilmu Sql

select distinct a.tahun, a.bulan, a.tanggal, userid from (
    select distinct year(logtime) tahun, month(logtime) bulan, day(logtime) tanggal
    from ngac_log
    where year(logtime)=2012 and month(logtime)=5
)a left join (
    select distinct userid, year(logtime) tahun, month(logtime) bulan, day(logtime) tanggal
    from ngac_log
    where year(logtime)=2012 and month(logtime)=5 and userid='002412430000000'
) b on (a.tahun=b.tahun and a.bulan=b.bulan and a.tanggal=b.tanggal)
order by 3

show full fields from database.nama_tabel

show full tables from nama_tabel where table_type = 'BASE TABLE'

select VERSION()

tutorial yang bagus bagi yang ingin mempelajari Partition Table di MySQL
http://www.slideshare.net/datacharmer/mysql-partitions-tutorial