Handle stat per statement type
Merge pull request #2 from rjuju/stat_by_cmdtype

Handle stat per statement type
Change hardcoded blocksize to current_setting('block_size')
Add a reads_raw column to pg_stat_kcache view

Per idea of Julien Rouhaud
Change pg_stat_kcache() function definition to return a column reads_raw instead of reads

Per comment of Julien Rouhaud
Add a pg_stat_kcache_detail view giving reads per operation type.