GreenPlum 大数据平台--运维(二)

1.如何获取查询运行时和已用时间。

例子:
Select tstart, tfinish, (tfinish-tstart) as total_time, trim(query_text) 
from queries_history 
Where tstart >= '2011-07-07 11:00:00' and tstart < '2011-07-07 13:00:00'
and db ='yourdatabasename'
Order by tstart; 

2。
*查看上次执行的操作

gpdb=# SELECT schemaname as schema, objname as table, usename as role, actionname as action,
gpdb-# subtype as type, statime as time
gpdb-# FROM pg_stat_operations
gpdb-# WHERE objname='cust';
 schema | table | role | action | type | time
--------+-------+------+--------+------+------
(0 rows)

*最后分析或创建表或ETC...

Select * from pg_stat_operations  
where schemaname='SCHEMA NAME '
and actionname in ('ANALYZE','VACUUM')  
order by statime; 

gpdb=# Select * from pg_stat_operations
gpdb-# where schemaname='SCHEMA NAME '
gpdb-# and actionname in ('ANALYZE','VACUUM')
gpdb-# order by statime;
 classname | objname | objid | schemaname | usestatus | usename | actionname | subty
pe | statime
-----------+---------+-------+------------+-----------+---------+------------+------
---+---------
(0 rows)

3.显示已关闭的细分。
select * from gp_segment_configuration where status='d';
4.如何计算磁盘中的数据库大小？
select pg_size_pretty(pg_database_size('test1')); 
5.如何计算磁盘中的表大小？
select pg_size_pretty(pg_relation_size('gpdb' ));  
6.对于分区表，您需要使用下面的sql来查找累积表大小
select sum(pg_total_relation_size(tablename)) from pg_tables where tablename like 'table_name%' ;
7。
*授予/撤消模式中对象的权限的功能

*撤销模式对象（表，视图，序列）权限的功能

8. GreenPlum数据库GUI工具

9.您可能喜欢的数据偏斜查询

gpdb=# select gp_segment_id, count(*) , abs(count(*) - avg(count(*)) over(order by gp_segment_id rowsbetween unbounded preceding and unbounded following))/count(*) skewfrom  test1group by gp_segment_idorder by skew desclimit  10;
 gp_segment_id | count |          skew
---------------+-------+------------------------
             1 |     2 | 0.40000000000000000000
             3 |     1 | 0.20000000000000000000
             4 |     1 | 0.20000000000000000000
             6 |     1 | 0.20000000000000000000
             0 |     1 | 0.20000000000000000000
(5 rows)

10。
*segments

gpdb=# SELECT count(*)::smallint AS numsegments FROM gp_segment_configurationWHERE gp_segment_configuration.preferred_role = 'p'::"char" ANDgp_segment_configuration.content >= 0;
 numsegments
-------------
           8
(1 row)

*segments的大小

gpdb=# SELECT pg_size_pretty(dfspace)FROM gp_toolkit.gp_disk_freeORDER BY dfsegment;
 pg_size_pretty
----------------
 39 MB
 39 MB
 39 MB
 39 MB
 39 MB
 39 MB
 39 MB
 39 MB
(8 rows)

11.确定当前的主段配置

gpdb=# SELECT dbid, content, address as host_address, port, replication_port, fselocation as datadirFROM gp_segment_configuration, pg_filespace_entryWHERE dbid=fsedbidORDER BY dbid;
 dbid | content | host_address | port  | replication_port |             datadir

------+---------+--------------+-------+------------------+-------------------------
--------
    1 |      -1 | greenplum01  |  5432 |                  | /greenplum/data/master/g
pseg-1
    2 |       0 | greenplum02  |  6000 |            34000 | /greenplum/data/primary/
gpseg0
    3 |       1 | greenplum02  |  6001 |            34001 | /greenplum/data/primary/
gpseg1
    4 |       2 | greenplum02  |  6002 |            34002 | /greenplum/data2/primary
/gpseg2
    5 |       3 | greenplum02  |  6003 |            34003 | /greenplum/data2/primary
/gpseg3
    6 |       4 | greenplum03  |  6000 |            34000 | /greenplum/data/primary/
gpseg4
    7 |       5 | greenplum03  |  6001 |            34001 | /greenplum/data/primary/
gpseg5
    8 |       6 | greenplum03  |  6002 |            34002 | /greenplum/data2/primary
/gpseg6
    9 |       7 | greenplum03  |  6003 |            34003 | /greenplum/data2/primary
/gpseg7
   10 |       0 | greenplum03  | 43000 |            44000 | /greenplum/data/mirror/g
pseg0
   11 |       1 | greenplum03  | 43001 |            44001 | /greenplum/data/mirror/g
pseg1
   12 |       2 | greenplum03  | 43002 |            44002 | /greenplum/data2/mirror/
gpseg2
   13 |       3 | greenplum03  | 43003 |            44003 | /greenplum/data2/mirror/
gpseg3
   14 |       4 | greenplum02  | 43000 |            44000 | /greenplum/data/mirror/g
pseg4
   15 |       5 | greenplum02  | 43001 |            44001 | /greenplum/data/mirror/g
pseg5
   16 |       6 | greenplum02  | 43002 |            44002 | /greenplum/data2/mirror/

12.时区设置：

gpdb=# BEGIN; 
gpdb=# SELECT NOW(); 
gpdb=# SET timezone TO '-8';                               
gpdb=# SELECT NOW();   

13.Re-create GP Toolkit objects:

You only get one shot, do not miss your chance to blow.