当一组相关的 Oracle 表都没有时间信息时，按天对它们进行分区

Question

我有一组看起来与此类似的表格：

Time_Table（比较小）：

Time      (TIMESTAMP)
timeId    (NUMBER)
Data...   (NUMBER)

表 2（大，每 time_table 行约 30 行）：

timeId    (NUMBER)
table2Id  (NUMBER)
Data...   (NUMBER)

Table3（非常大，每个 table2 行大约 10 行，目前在几百天后有 14 亿行）：

timeId    (NUMBER)
table2Id  (NUMBER)
table3Id  (NUMBER)
Data...   (NUMBER)

我的查询总是至少加入 timeId，并且每个查询被分成几天（10 天读取将导致 10 个较小的查询）。每天都有新数据写入所有表。我们需要从这些表中存储（和查询）多年的数据。

当只能通过 JOIN 获知时间信息时，如何将这些表划分为每日块？我是否应该考虑以不依赖时间的方式进行分区？这可以自动完成，还是必须手动完成？

Oracle 版本 11.2

Answer 1

参考分区在这里可能有所帮助。它允许 child table 的分区方案由 parent table.

确定

架构

--drop table table3;
--drop table table2;
--drop table time_table;

drop table time_table;
create table Time_Table
(
    time   TIMESTAMP,
    timeId NUMBER,
    Data01 NUMBER,
    constraint time_table_pk primary key (timeId)
)
partition by range (time)
(
    partition p1 values less than (date '2000-01-02'),
    partition p2 values less than (date '2000-01-03'),
    partition p3 values less than (date '2000-01-04')
);

create table table2
(
    timeId   number,
    table2Id number,
    Data01   number,
    constraint table2_pk primary key (table2ID),
    constraint table2_fk foreign key (timeId) references time_table(timeId)
);


create table table3
(
    timeId   number not null,
    table2Id number,
    table3Id number,
    Data01   number,
    constraint table3_pk primary key (table3ID),
    constraint table3_fk1 foreign key (timeId) references time_table(timeId),
    constraint table3_fk2 foreign key (table2ID) references table2(table2ID)
) partition by reference (table3_fk1);

执行计划

Pstart 和 Pstop 显示大 child table 被正确修剪，即使分区谓词仅设置在小 parent 上table.

explain plan for
select *
from table3
join time_table using (timeId)
where time = date '2000-01-02';

select * from table(dbms_xplan.display);

Plan hash value: 832465087

-----------------------------------------------------------------------------------------------------
| Id  | Operation              | Name       | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |
-----------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT       |            |     1 |    91 |     3   (0)| 00:00:01 |       |       |
|   1 |  PARTITION RANGE SINGLE|            |     1 |    91 |     3   (0)| 00:00:01 |     2 |     2 |
|   2 |   NESTED LOOPS         |            |     1 |    91 |     3   (0)| 00:00:01 |       |       |
|*  3 |    TABLE ACCESS FULL   | TIME_TABLE |     1 |    39 |     2   (0)| 00:00:01 |     2 |     2 |
|*  4 |    TABLE ACCESS FULL   | TABLE3     |     1 |    52 |     1   (0)| 00:00:01 |     2 |     2 |
-----------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   3 - filter("TIME_TABLE"."TIME"=TIMESTAMP' 2000-01-02 00:00:00')
   4 - filter("TABLE3"."TIMEID"="TIME_TABLE"."TIMEID")

Note
-----
   - dynamic sampling used for this statement (level=2)
   - automatic DOP: skipped because of IO calibrate statistics are missing

警告

参考分区有一些怪癖。它不适用于 11g 中的间隔分区，因此您必须手动定义 parent table 的每个分区。外键也无法禁用，这可能需要修改一些脚本。和任何很少使用的功能一样，它也有一些错误。

Answer 2

drop table time_table;
create table Time_Table
(
    time   TIMESTAMP,
--    timeId NUMBER, Why you need ID when you have timestamp?????
    Data01 NUMBER,
    constraint time_table_pk primary key (time) -- not timeID!!!
)
partition by range (time)
(
    partition p1 values less than (date '2000-01-02'),
    partition p2 values less than (date '2000-01-03'),
    partition p3 values less than (date '2000-01-04')
);

create table table2
(
    time     timestamp not null,
    table2ID number,
    Data01   number
)
partition by range (time)
(
    partition p1 values less than (date '2000-01-02'),
    partition p2 values less than (date '2000-01-03'),
    partition p3 values less than (date '2000-01-04')
);


create table table3
(
    time     timestamp not null,
    table2Id number,
    table3Id number,
    Data01   number
) 
partition by range (time)
(
    partition p1 values less than (date '2000-01-02'),
    partition p2 values less than (date '2000-01-03'),
    partition p3 values less than (date '2000-01-04')
);

当一组相关的 Oracle 表都没有时间信息时，按天对它们进行分区

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