select to_char(log.date, 'yyyy-MM-dd HH24') as hour,
  log.exten, sum(case log.grade when '1' then 1 else 0 end) as "1",
  sum(case log.grade when '2' then 1 else 0 end) as "2",
  sum(case log.grade when '3' then 1 else 0 end) as "3",
  sum(case log.grade when '4' then 1 else 0 end) as "4",
  sum(case log.grade when '5' then 1 else 0 end) as "5",
  log.direction from iface_satisfaction_investigation as log 
where log.date >= '2017-08-03 00:00:00' and log.date  '2017-08-04 00:00:00' 
group by hour,log.exten,log.direction order by hour,log.exten,log.direction asc

/*計算表的空間大小*/
select oid,table_schema as "模式",
	table_name as "表名",
	row_estimate::bigint as "表中的行數(估計值)",
	pg_size_pretty(total_bytes) as "總大小",
  pg_size_pretty(table_bytes) as "表大小",
	pg_size_pretty(index_bytes) as "索引大小",
  pg_size_pretty(toast_bytes) as "toast表總大小"  
from (
	select *, total_bytes-index_bytes-coalesce(toast_bytes,0) as table_bytes 
		from (
			select
				c.oid,
				nspname as table_schema,
				relname as table_name,
				c.reltuples as row_estimate,
				pg_total_relation_size(c.oid) as total_bytes,
				pg_indexes_size(c.oid) as index_bytes,
				pg_total_relation_size(reltoastrelid) as toast_bytes
			from pg_class c
			left join pg_namespace n on n.oid = c.relnamespace
			where relkind = 'r'
 ) t1 
) t2 order by 2,3;
/*統計用戶表信息*/
select 
	schemaname as "模式",
	relname as "表名",
	seq_scan as "順序掃描的次數",
	seq_tup_read as "順序掃描獲取活動行的數量",
	idx_scan as "索引掃描次數",
	idx_tup_fetch as "索引掃描獲取活動行的數量",
	n_tup_ins as "累計插入的行數",
	n_tup_upd as "累計更新的行數(包含HOT 更新的行)",	
	n_tup_del as "累計刪除的行數",
	n_live_tup as "當前活動行估計數量",
	n_dead_tup as "當前死亡行的估計數量",
	n_mod_since_analyze as "最后一次分析后被修改的行估計數量",
	last_vacuum as "上次被手動清理的時間(不統計VACUUM FULL)",
	last_autovacuum as "上次自動清理的時間",
	last_analyze as "上次手動分析的時間",
	last_autoanalyze as "上次自動清理分析的時間",
	vacuum_count as "手動清理的次數",
	autovacuum_count as "自動清理的次數",
	analyze_count as "手動分析的次數",
	autoanalyze_count as "自動分析的次數",
	pg_size_pretty(pg_table_size(relid)) as "表大小(不包含索引)"
from pg_stat_user_tables
order by 1;
/*統計用戶表IO信息*/
select
	schemaname as "模式",
	relname as "表名",
	heap_blks_read as "讀取的磁盤塊數量",
	heap_blks_hit as "緩沖區命中數量",
	idx_blks_read as "表上所有索引讀取的磁盤塊數",
	idx_blks_hit as "表上的所有索引緩沖區命中數量",
	toast_blks_read as "TOAST表(如果有)讀取的磁盤塊數",
	toast_blks_hit as "TOAST表(如果有)緩沖區命中數量",
	tidx_blks_read as "TOAST表索引(如果有)讀取的磁盤塊數",
	tidx_blks_hit as "TOAST表索引(如果有)緩沖區命中數量"
from pg_statio_user_tables
order by 1;
/*統計用戶索引信息*/
select 
	indexrelid,
	schemaname as "模式",
	relname as "索引所在的表名稱",
	indexrelname as "索引名稱",
	idx_scan as "索引掃描次數",
	idx_tup_read as "索引掃描返回的索引項數量",
	idx_tup_fetch as "簡單索引掃描獲取的活動行數量",
	pg_size_pretty(pg_relation_size(indexrelid)) as "索引大小"
from pg_stat_user_indexes
order by 1,2;
/*追蹤函數,需要打開track_functions參數(默認關閉)*/
select * from pg_stat_user_functions;