Greenplum使用简明手册
GP服务启停
su - gpadmin
gpstart #正常启动
gpstop #正常关闭
gpstop -M fast #快速关闭
gpstop –r #重启
gpstop –u #重新加载配置文件
登陆与退出Greenplum
#正常登陆
psql gpdb
psql -d gpdb -h gphostm -p 5432 -U gpadmin
#使用utility方式
PGOPTIONS="-c gp_session_role=utility" psql -h -d dbname hostname -p port
#退出
在psql命令行执行\q
参数查询
psql -c 'SHOW ALL;' -d gpdb
gpconfig --show max_connections
创建数据库 createdb -h localhost -p 5432 dhdw
创建GP文件系统
# 文件系统名
gpfsdw
# 子节点，视segment数创建目录
mkdir -p /gpfsdw/seg1
mkdir -p /gpfsdw/seg2
chown -R gpadmin:gpadmin /gpfsdw
# 主节点
mkdir -p /gpfsdw/master
chown -R gpadmin:gpadmin /gpfsdw
gpfilespace -o gpfilespace_config
gpfilespace -c gpfilespace_config
创建GP表空间
psql gpdb
create tablespace TBS_DW_DATA filespace gpfsdw;
SET default_tablespace = TBS_DW_DATA;
删除GP数据库 gpdeletesystem -d /gpmaster/gpseg-1 -f
查看segment配置 select * from gp_segment_configuration;
文件系统 select * from pg_filespace_entry;
磁盘、数据库空间
SELECT * FROM gp_toolkit.gp_disk_free ORDER BY dfsegment;
SELECT * FROM gp_toolkit.gp_size_of_database ORDER BY sodddatname;
日志
SELECT * FROM gp_toolkit.__gp_log_master_ext;
SELECT * FROM gp_toolkit.__gp_log_segment_ext;
表数据分布 SELECT gp_segment_id, count(*) FROM <table_name> GROUP BY gp_segment_id;
表占用空间
SELECT relname as name, sotdsize/1024/1024 as size_MB, sotdtoastsize as toast, sotdadditionalsize as other
FROM gp_toolkit.gp_size_of_table_disk as sotd, pg_class
WHERE sotd.sotdoid = pg_class.oid ORDER BY relname;
索引占用空间
SELECT soisize/1024/1024 as size_MB, relname as indexname
FROM pg_class, gp_toolkit.gp_size_of_index
WHERE pg_class.oid = gp_size_of_index.soioid
AND pg_class.relkind='i';
OBJECT的操作统计
SELECT schemaname as schema, objname as table, usename as role, actionname as action, subtype as type, statime as time
FROM pg_stat_operations
WHERE objname = '<name>';
锁
SELECT locktype, database, c.relname, l.relation, l.transactionid, l.transaction, l.pid, l.mode, l.granted, a.current_query
FROM pg_locks l, pg_class c, pg_stat_activity a
WHERE l.relation=c.oid
AND l.pid=a.procpid
ORDER BY c.relname;
队列 SELECT * FROM pg_resqueue_status
查看指定数据库 select pg_size_pretty(pg_database_size('<database_name>'));
所有数据库 select datname,pg_size_pretty(pg_database_size(<database_name>)) from pg_database;
查看数据库表清单(包括临时表) pg_tables
主表与分区表 pg_partitions
字段清单 information_schema.columns
视图 pg_views
字典 schema : information_schema
GP中查询表和视图清单，视图的字段及其类型
查询schema_name.view_name的字段及其类型：
select a.attname, pg_catalog.format_type(a.atttypid, a.atttypmod) as type,a.attnotnull
from pg_catalog.pg_attribute a,pg_catalog.pg_class c, pg_catalog.pg_namespace n
where a.attrelid=c.oid
and c.relname='view_name'
and a.attnum>0 AND NOT a.attisdropped
and n.oid = c.relnamespace
and n.nspname='schema_name'
order by a.attnum
查询指定schema下view的清单：
select c.relname
from pg_catalog.pg_class c, pg_catalog.pg_namespace n
where n.oid = c.relnamespace
and n.nspname='schema_name'
and c.relkind='v'
查询指定schema下所有table的清单：
select c.relname
from pg_catalog.pg_class c, pg_catalog.pg_namespace n
where n.oid = c.relnamespace
and n.nspname='schema_name'
and c.relkind='r'
查询指定schema下所有外部表的清单：
select c.relname
from pg_catalog.pg_class c, pg_catalog.pg_namespace n
where n.oid = c.relnamespace
and n.nspname='schema_name'
and c.relkind='r' and relstorage='x'
查询指定schema下所有普通表的清单：
select c.relname
from pg_catalog.pg_class c, pg_catalog.pg_namespace n
where n.oid = c.relnamespace
and n.nspname='schema_name'
and c.relkind='r' and relstorage in ('h','a');
注意，relstorage字段取值“x”表示外部表，“h”表示heap表，“a”表示append-only表，“v”表示virtual表。
查询指定schema_name下table_owner的表：
select * from
(
select c.relname, pg_catalog.pg_get_userbyid(c.relowner) as table_owner
from pg_catalog.pg_class c, pg_catalog.pg_namespace n
where n.oid = c.relnamespace
and n.nspname='schema_name'
) t where t.table_owner = 'table_owner';
查询指定指定table_owner的所有普通表：
select * from
(
select n.nspname, c.relname, pg_catalog.pg_get_userbyid(c.relowner) as table_owner
from pg_catalog.pg_class c, pg_catalog.pg_namespace n
where n.oid = c.relnamespace and c.relkind='r' and relstorage in ('h', 'a')
) t where t.table_owner = 'table_owner';
加载（LOAD）数据到Greenplum数据库
gpfdist外部表
# 启动服务
gpfdist -d /share/txt -p 8081 –l /share/txt/gpfdist.log &
# 创建外部表，分隔符为’/t’
drop EXTERNAL TABLE TD_APP_LOG_BUYER;
CREATE EXTERNAL TABLE TD_APP_LOG_BUYER (
IP text,
ACCESSTIME text,
REQMETHOD text,
URL text,
STATUSCODE int,
REF text,
name text,
VID text)
LOCATION ('gpfdist://gphostm:8081/xxx.txt')
FORMAT 'TEXT' (DELIMITER E'/t'
FILL MISSING FIELDS) SEGMENT REJECT LIMIT 1 percent;
# 创建普通表
create table test select * from TD_APP_LOG_BUYER;
# 索引
# CREATE INDEX idx_test ON test USING bitmap (ip);
# 查询数据
select ip , count(*) from test group by ip order by count(*);
gpload
# 创建控制文件
# 加载数据
gpload -f my_load.yml
copy
COPY country FROM '/data/gpdb/country_data'
WITH DELIMITER '|' LOG ERRORS INTO err_country
SEGMENT REJECT LIMIT 10 ROWS;
从Greenplum数据库卸载（UNLOAD）数据
gpfdist外部表
# 创建可写外部表
CREATE WRITABLE EXTERNAL TABLE unload_expenses
( LIKE expenses )
LOCATION ('gpfdist://etlhost-1:8081/expenses1.out',
'gpfdist://etlhost-2:8081/expenses2.out')
FORMAT 'TEXT' (DELIMITER ',')
DISTRIBUTED BY (exp_id);
# 写权限
GRANT INSERT ON writable_ext_table TO <name>;
# 写数据
INSERT INTO writable_ext_table SELECT * FROM regular_table;
copy
COPY (SELECT * FROM country WHERE country_name LIKE 'A%') TO '/home/gpadmin/a_list_countries.out';
执行sql文件
psql gpdbname –f yoursqlfile.sql
或者psql登陆后执行
\i yoursqlfile.sql
如何杀掉greenplum、postgresql的会话进程
在linux命令行执行kill -s SIGTERM <procid>杀掉该会话的进程
用函数杀sql
对于查询SQL
select pg_cancel_backend(procpid);
其他SQL
select pg_terminate_backend(procpid);
调整Greenplum的SQL查询计划
在oracle中使用hint可以调整SQL的执行计划，在postgresql可以使用如下的方法进行调整
使用set<option> to off/on;调整查询计划，参数如下:
enable_seqscan 是否走全表扫描
enable_hashjoin 是否允许走
hash 连接
enable_nestloop 是否允许走
nestloo 连接
enable_mergejoin 是否允许走合并连接
enable_tidscan 是否允许走tid 扫描（类似oracle中的按rowid访问）
enable_bitmapscan 是否允许走
bitmap 扫描
enable_hashagg 是否允许走
hash 聚集（也就是做group by时）
enable_indexscan 是否允许走索引
enable_sort 是否允许走排序
constraint_exclusion 是否允许走分区
