官方文档

查看版本

show variables like 'version%'

日期格式化

select date_format(now(),'%Y%m%d');
select date_format(curdate(),'%Y%m%d');
select date_format(date_add(curdate(), interval -1 day),'%Y%m%d');
select date_format(date_add(20220620, interval 6 day),'%Y%m%d');

特殊限制

• between 隐式转换 '' 转 int 会报错
• order by 默认限制最大 65535
• 字段名不支持中文
• 中文存储需要占 3 位

性能优化

• 稀疏索引

  每张表都有的前缀索引，需要注意建表顺序 、 排序列的顺序

• bloomfilter索引

  适用 store_code / goods_sn/shop_code

  ALTER TABLE example_db.my_table SET ("bloom_filter_columns" = ""); -- 删除索引
  ALTER TABLE example_db.my_table SET ("bloom_filter_columns" = "goods_sn,shop_code"); -- 修改索引
  

• 倒排索引

  适用 is_ht

• 内存表

  适用维度表

• 可对维度表设置更多的副本，提升 Join 的性能

  ALTER TABLE example_db.my_table SET ("replication_num" = "7");
  

权限

-- 创建用户
CREATE USER ods@'%' IDENTIFIED BY 'ods.com.1234';
-- 授权
GRANT SELECT_PRIV, LOAD_PRIV, ALTER_PRIV, CREATE_PRIV, DROP_PRIV   ON ods.* TO 'ods'@'%';

物化视图

限制：不能加过滤条件；不支持表关联；只支持明细模型

• 创建

  create materialized view vfact_shop_inventory_available_day_goods_sum as 
  select dateid,dateid2,shop_code,goods_sn,sum(qty) as qty, sum(qtyavailable) as qtyavailable
  from fact_shop_inventory_available_day
  group by dateid,dateid2,shop_code,goods_sn
  

• 查看进度

  show alter table materialized view from ebi
  

• 查看

  desc  ebi.fact_shop_inventory_available_day  all
  

• 删除

  drop  materialized view vfact_shop_inventory_available_day_goods_sum on fact_shop_inventory_available_day
  

同步落地表

-- ebi.config_store definition
DROP TABLE config_order_deal_code;
CREATE TABLE `config_order_deal_code` (
`id` bigint  null,
`shop_code` varchar(64) null,
`order_deal_code` varchar(500) null,
`created_by` bigint  null,
`created_time` datetime  null,
`updated_by` bigint  null,
`updated_time` datetime  null
) ENGINE=OLAP
UNIQUE KEY(`id`)
COMMENT "OLAP"
DISTRIBUTED BY HASH(`id`) BUCKETS 4
PROPERTIES (
"replication_num" = "3",
"in_memory" = "false",
"storage_format" = "V2"
);

-- 补序列字段
ALTER TABLE gds_btgoods ENABLE FEATURE "SEQUENCE_LOAD" WITH PROPERTIES ("function_column.sequence_type" = "bigint");

动态分区

CREATE TABLE `fact_vip_settlement_day_hour_goods_ads_sum_realtime` (
  `order_type_id` int(11) NOT NULL COMMENT "",
  `dateid` int(11) NOT NULL COMMENT "",
  `add_dateid` int(11) NULL COMMENT "",
  `pay_dateid` int(11) NULL COMMENT "",
  `goods_sn` varchar(240) NOT NULL COMMENT "",
  `is_ht` bigint(20) NOT NULL COMMENT "",
  `salesAmount` decimal(20, 6) NOT NULL COMMENT "",
  `goods_number` int(11) NOT NULL COMMENT "",
  `order_from` varchar(16) NOT NULL COMMENT "",
  `vendor_code` varchar(64) NOT NULL COMMENT "",
  `utc` int(11) NOT NULL COMMENT "",
  `hour` int(11) NULL COMMENT ""
) ENGINE=OLAP
COMMENT "唯品会结算(货号+小时)(实时近30天)"
PARTITION BY RANGE(dateid) ()
DISTRIBUTED BY HASH(dateid)
PROPERTIES
(
    "dynamic_partition.create_history_partition" = "true",
    "dynamic_partition.history_partition_num" = "30",
    "dynamic_partition.enable" = "true",
    "dynamic_partition.time_unit" = "DAY",
    "dynamic_partition.start" = "-30",
    "dynamic_partition.end" = "1",
    "dynamic_partition.prefix" = "p",
    "dynamic_partition.buckets" = "8"
)

常用sql

-- 查看隐藏列
set show_hidden_columns=true
-- 增加数据库配额
alter database testdb set data quota 100t
-- 删除不管分区
set delete_without_partition=true;
-- 设置严格模式
show global variables like '%enable_insert_strict%'
set global enable_insert_strict=true
-- 查看表变更进度
show alter table column order by createtime desc
-- 修改表注释
alter table order_return_goods_history2021 modify comment '换货新单商品明细（2021归档）';

资源组

-- 限制用户资源组
SET PROPERTY FOR 'ebi_acc' 'resource_tags.location' = 'acc';

-- 查看用户属性
SHOW PROPERTY FOR ebi_acc

-- 修改表副本分布
alter table dis_capital_account_occupied_fund MODIFY PARTITION (*) set ("replication_allocation"="tag.location.default:5");
alter table dis_capital_account_occupied_fund MODIFY PARTITION (*) set ("replication_allocation"="tag.location.default:3, tag.location.acc:2");

-- 查看分区情况
show partitions from dis_capital_account_occupied_fund

修改配置

# 查看BE配置
http://10.211.6.136:8040/varz

# 动态修改BE配置持久化
curl -X POST http://10.211.6.136:8040/api/update_config?streaming_load_json_max_mb=10240\&persist=true