~~~ connect to [数据库名] user [操作用户名] using [密码] ~~~ 连接到数据库指定数据库，不包含中括号 ~~~ reorgchk on table EAS.T_User ~~~ 检测是否需要重组表EAS.T_User ~~~ reorgchk update statistics on table all ~~~ 检测所有表是否需要重组 select tabname, colcount, status  FROM syscat.tables   WHERE tabschema NOT LIKE 'SYS%'  ORDER BY tabname 状态是否正常状态列 N = 正常；C = 待审核 get snapshot for bufferpools on 数据库名 检测快照缓冲池命中率>95%？ get snapshot for Locks on EASdb 检测快照锁 get snapshot for Locks on EASdb get snapshot for all  on EASdb 检测快照锁 select index_hit_ratio_percent  from sysibmadm.bp_hitratio  缓冲池命中率 select agent_id,rows_selected,rows_read from sysibmadm.application_performance 查看系统性能 select elapsed_time_min,appl_status,agent_id from sysibmadm.long_running_sql order by elapsed_time_min desc fetch first 5 rows only 查看运行时间最长的应用 select * from sysibmadm.top_dynamic_sql order by num_executions desc  查看运行次数最多的SQL select tabschema, tabname  from syscat.tables where stats_time is null 查看没有统计信息的表 select  tabname  from syscat.indexes where stats_time is null 查看没有统计信息的索引 reorg table EAS.T_City 重组单表 reorg indexes all for table 表名 只重组索引 runstats on table EAS.t_group and detailed indexes all 重新统计表和索引 list applications show detail 显示所用应用情况 list tablespaces show detail 显示所用表空间情况 create unique index t_groupIdCODEname  on eas.t_group  (G_ID asc,G_CODE,G_NAME)  allow reverse scans 创建可以反向扫描的唯一索引，在需要排序时 create index t_groupIdCODEname  on eas.t_group  (G_ID asc) include(G_CODE,G_NAME) 创建include的索引 create table eas.t1(c1 int,c2 double,c3 double generated always as c1+c2,c4 generated always as( case when c1>c2  then 1 else null end)) 创建具有计算列的表 一般再有大量的删除，修改，增加时需要reorg table，在进行runstats on table