DB2部分查询SQL

/*
部分SQL
*/

--添加主键
alter TABLE TABLE_SCHEMA.TABLE_NAME 
    add constraint PK_TABLE_NAME
    primary key(COL1 ,COL2);

--收集统计信息runsats
db2 "runstats on table tbschema.tbname with distribution on all columns and indexes all" 

/*
  以下为数据库监控部分
*/
--监控最耗费用户CPU的时间的动态SQL
select STMT_TEXT from sysibmadm.snapdyn_sql order by total_usr_cpu_time desc fetch first 5 rows only

--监控访问热点对象执行次数最多的SQL,<TableName>指热点表名
select STMT_TEXT,num_executions 
from sysibmadm.snapdyn_sql where stmt like '%<TableNameForHotIndex>%'
order by num_executions desc fetch first 5 rows only

--监控访问热点对象执行次数最多的SQL,<TableNameForHotIndex>指热点索引
select STMT_TEXT,num_executions 
from sysibmadm.snapdyn_sql where stmt like '%<TableNameForHotIndex>%'
order by pool_index_p_reads desc fetch first 5 rows only

--监控运行时间最长的SQL
select * from sysibmadm.long_running_sql
order by elapsed_time_min desc
fetch first 1 rows only

--监控运行次数最多的SQL
select stmt_text,num_executions from sysibmadm.top_dynamic_sql
order by num_executions desc
fetch first 5 row only

--监控排序次数最多的SQL
select stmt_text,stmt_sorts from sysibmadm.top_dynamic_sql
order by stmt_sorts desc
fetch first 5 row only

--日志写入速度
db2 "select (log_write_time_ns/1000000)/num_log_write_io as average_log_wirte_ms from sysibmadm.snapdb"

--锁升级及死锁
db2 "select lock_escals,deadlocks from sysibmadm.snapdb"

--获取所有管理视图
db2 list tables for schema SYSIBMADM

--查看表结构
db2look -d test -e -nofed -t test.test1 | awk '/CREATE TABLE/,/;/{print}'

--查看执行计划
db2 connect to test
db2 "explain plan for select distinct contno from table_schema.table_name"
db2exfmt -d  test -1 -o /tmp/a.exfmt
more /tmp/a.exfmt

--修改表名
RENAME TABLE_SCHEMA.OLD_TABLENAME TO NEW_TABLENAME;

--修改表字段
ALTER TABLE TABLE_SCHEMA.OLD_TABLENAME ALTER COLUMNS SET DATA TYPE VARCHAR(10);

--修改字段名称【DB2不允许修改字段名称，但是可以删除后新增字段】
ALTER TABLE TABLE_SCHEMA.TABLE_NAME DROP COLUMNS;
ALTER TABLE TABLE_SCHEMA.TABLE_NAME ADD COLUMNS VARCHAR(10);

参考资料：

DB2设计、管理与性能优化艺术 --王飞鹏 、 李玉明 、 朱志辉 、 王富国 等  著  胡伟民  校