Choosing the target number of partitions that the table should be divided into is also a critical decision to make. Not having enough partitions may mean that indexes remain too large and that data locality remains poor which could result in low cache hit ratios. However, dividing the table in...
查看分区数据user_part_tables(分区数量及类型): 查看表分区规则user_tab_partitions 有二级分区,查询二级分区 range+list 通过组合range和list的方式对数据先进行范围分区,然后列表分区 create table T2 ( id number, p_month number, username varchar2(50), inputdata date, constraint T2_id primary key (id)...
postgres=# create tabletpart_list(a text primary key,b int,c int)partition bylist(a)configuration(valuesin('a'),('b'),('c'),('d')defaultpartition tpart_list_default);CREATETABLE 会自动创建5个分区:a、b、c、d和默认分区: 代码语言:javascript 复制 postgres=# \d+tpart_list Partitioned ...
找到create table 输入名字、开启分区(会提示你指定分区表key,先不管) 写表属性,必须包含一个分区逻辑字段,我这里以时间分区(date),(注意不能出现主键索引,否者会报错) 找到partitions,可以看到有三种partition type这里我是用list 范围(Range )分区: 表被划分为由键列或列集定义的“范围”,分配给不同分区的值的...
默认分区,用于处理没有分区表的异常插入情况,用于存储无法匹配其他任何分区表的数据。显然,只有 RANGE 分区表和 LIST 分区表需要默认分区。 创建默认分区时,使用 DEFAULT 子句替代 FOR VALUES 子句。 CREATETABLEmeasurement_default PARTITIONOFmeasurementDEFAULT; ...
CREATE TABLE AB_negative PARTITION of donors for VALUES IN ('AB-'); CREATE TABLE O_positive PARTITION of donors for VALUES IN ('O+ '); CREATE TABLE O_negative PARTITION of donors for VALUES IN ('O- '); List partitions are seen in the table definition below: 1 2 3 4 5 6 7 8 ...
Partition key: LIST (status) Partitions: stu_active FOR VALUES IN ('ACTIVE'), stu_exp FOR VALUES IN ('EXPIRED'), stu_others DEFAULT postgres=# \d+ stu_active Table "public.stu_active" Column | Type | Collation | Nullable | Default | Storage | Stats target | Description ...
PostgreSQL 11 的一个重量级新特性为分区表得到较大增强,例如支持哈希分区(HASH)表,因此 PostgreSQL 支持范围分区(RANGE)、列表分区(LIST)、>哈希分区(HASH)三种分区方式,本文简单演示下哈希分区表。 Hash Partitioning The table is partitioned by specifying a modulus and a remainder for each partition. Each pa...
create table log_history(idint not null,logdatedatenot null,num int) partition by range(logdate); 创建分区 create table log_history_2001 partition of log_historyforvalues from ('2001-01-01') to ('2001-12-31'); create table log_history_2002 partition of log_historyforvalues from ('2002...
-- Create the partitioned tableCREATETABLEcustomers ( id SERIAL, nameVARCHAR(100), countryVARCHAR(100) )PARTITIONBYLIST (country);-- Create partitionsCREATETABLEcustomers_usaPARTITIONOFcustomersFORVALUESIN('USA');CREATETABLEcustomers_ukPARTITIONOFcustomersFORVALUESIN('UK');CREATETABLEcustomers_canadaPARTITI...