步骤3:调优表操作具体步骤
选择存储方式
此实践中所使用的样例表为典型的TPC-DS表,是典型的多字段表,统计分析类查询场景多,因此选择列存存储方式。
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WITH (ORIENTATION = column) |
选择压缩级别
在步骤1:创建初始表并加装样例数据中没有指定压缩比,GaussDB(DWS)默认为用户选择LOW级别压缩比。在这一步中把压缩比调整为MIDDLE级别,进行验证对比。
增加存储方式和压缩比后的建表样例如下:
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CREATE TABLE store_sales ( ss_sold_date_sk integer , ss_sold_time_sk integer , ss_item_sk integer not null, ss_customer_sk integer , ss_cdemo_sk integer , ss_hdemo_sk integer , ss_addr_sk integer , ss_store_sk integer , ss_promo_sk integer , ss_ticket_number bigint not null, ss_quantity integer , ss_wholesale_cost decimal(7,2) , ss_list_price decimal(7,2) , ss_sales_price decimal(7,2) , ss_ext_discount_amt decimal(7,2) , ss_ext_sales_price decimal(7,2) , ss_ext_wholesale_cost decimal(7,2) , ss_ext_list_price decimal(7,2) , ss_ext_tax decimal(7,2) , ss_coupon_amt decimal(7,2) , ss_net_paid decimal(7,2) , ss_net_paid_inc_tax decimal(7,2) , ss_net_profit decimal(7,2) ) WITH (ORIENTATION = column,COMPRESSION=middle); |
选择分布方式
依据步骤2:测试初始表结构下的系统性能并建立基线中所基线的各表大小,分布方式设置如下:
表名 |
行数 |
分布方式 |
---|---|---|
Store_Sales |
287997024 |
Hash |
Date_Dim |
73049 |
Replication |
Store |
402 |
Replication |
Item |
204000 |
Replication |
Time_Dim |
86400 |
Replication |
Promotion |
1000 |
Replication |
Customer_Demographics |
1920800 |
Hash |
Customer_Address |
1000000 |
Hash |
Household_Demographics |
7200 |
Replication |
Customer |
1981703 |
Hash |
Income_Band |
20 |
Replication |
选择分布列
当表的分布方式选择了Hash分布策略时,分布列选取至关重要。在这一步中,建议按照选择分布列选择分布键:
选择各表的主键作为Hash表分布键。
表名 |
记录数 |
分布方式 |
分布键 |
---|---|---|---|
Store_Sales |
287997024 |
Hash |
ss_item_sk |
Date_Dim |
73049 |
Replication |
- |
Store |
402 |
Replication |
- |
Item |
204000 |
Replication |
- |
Time_Dim |
86400 |
Replication |
- |
Promotion |
1000 |
Replication |
- |
Customer_Demographics |
1920800 |
Hash |
cd_demo_sk |
Customer_Address |
1000000 |
Hash |
ca_address_sk |
Household_Demographics |
7200 |
Replication |
- |
Customer |
1981703 |
Hash |
c_customer_sk |
Income_Band |
20 |
Replication |
- |