分区键离散,可以使用PARTITION BY LIST。按字符串匹配决定落入哪个分区。 分区键连续,比如整形、日期等,可以使用PARTITION BY RANGE。 分区键数据随机无规律或规律简单,可以使用PARTITION BY HASH,用hash函数打散数据。 分区键数据随机有规律,规律复杂,可以使用多级混合分区,使数据平均分散、减少耦合。 每个分区都是一个...
(2)、列表分区表 CREATETABLElist_example(dnameVARCHAR2(10),DATAVARCHAR2(20))PARTITIONBYLIST(dname)(PARTITIONpart01VALUES('ME','PE','QC','RD'),PARTITIONpart02VALUES('SMT','SALE')); 1. 2. 3. 4. 5. 6. (3)、哈希分区表 CREATETABLEhash_example(hash_key_columnDATE,DATAVARCHAR2(20))PA...
partition by range(vdate) 增加附属表 1 2 3 4 CREATE TABLE cbd_cbdmodeldetails_1_2 PARTITION OF cbd_cbdmodeldetails FOR VALUES FROM (1) TO (3); CREATE TABLE cbd_cbdmodeldetails_3_6 PARTITION OF cbd_cbdmodeldetails FOR VALUES FROM (3) TO (7); --顾头不顾尾 改变主键属性 1. 不存在...
AI代码解释 DO$$BEGINEXECUTE'CREATE TABLE IF NOT EXISTS orders_'||EXTRACT(YEARFROMCURRENT_DATE+INTERVAL'1 year')||' PARTITION OF orders FOR VALUES FROM ('''||CURRENT_DATE+INTERVAL'1 year'||''') TO ('''||CURRENT_DATE+INTERVAL'2 years'||''')';END$$; 通过这种方式,每年年初会自动生...
but for datetime ordering columns it is an interval. For example, if the ordering column is of type date or timestamp, one could writeRANGE BETWEEN '1 day' PRECEDING AND '10 days'FOLLOWING. The offset is still required to be non-null and non-negative, though the meaning of “non-negati...
) PARTITION BY RANGE (order_date); 1. 2. 3. 4. 5. 6. 这一段代码为我们创建了一个分区表,其中根据order_date的值来进行数据分区。 分区表的优势 🚀 查询性能提升:当你查询某一年的数据时,PostgreSQL 只会访问那一年的分区,减少了扫描其他无关数据的时间。
In practical use cases of partitioned tables, the time field is generally used as the partition key; for example, if the partition field type is timestamp, the partitioning method can be "list of values". The table structure is as follows: ...
list 分区表 表格通过明确的键值进行分区。 创建主分区 postgres=# create table t_native_list(f1 bigserial not null,f2 text, f3 integer,f4 date) partition by list( f2 ) distribute by shard(f1); NOTICE: Replica identity is neededforshard table, pleaseaddto this table through"alter table...
2) Using PostgreSQL NTILE() function over a partition example This example uses the NTILE() function to divide rows in the sales_stats table into two partitions and 3 buckets for each: SELECT name, amount, NTILE(3) OVER( PARTITION BY year ORDER BY amount ) FROM sales_stats; Here is the...
PARTITION BY LIST (category); Create individual partitions for different categories CREATE TABLE products_electronics PARTITION OF products FOR VALUES IN ('Electronics', 'Appliances'); CREATE TABLE products_clothing PARTITION OF products FOR VALUES IN ('Clothing', 'Footwear'); ...