postgresql 數據庫中間件 pgoneproxy 實現冷熱數據分離查詢（二）

    在前一篇《postgresql中間件pgoneproxy支持冷熱數據分離查詢》中講解了按照id來進行數據的分離，針對時間至少稍微的提了一下。本篇這專門針對時間來進行講解和測試下。

    在個人數據庫中新建了一張表bigtest，其中字段狀況以下所示：

Table "public.bigtest_0"
 Column |            Type             | Modifiers 
--------+-----------------------------+-----------
 id     | integer                     | 
 name   | character varying(1024)     | 
 age    | integer                     | 
 tt     | timestamp without time zone |

如今按照tt字段來進行數據的分離插入和查詢。下面是bigtest表的分表的配置狀況：

{
        "table"  : "bigtest",
        "pkey"   :  "tt",
        "type"   :  "timestamp",
        "method" :  "buffer",
        "partitions":
        [
                {"suffix":"_0", "group":"data1", "minval":"2004-01-01 00:00:00", "maxval":"2015-01-01 00:00:00"},
                {"suffix":"_1", "group":"data1", "minval":"2015-01-01 00:00:01","maxval":"2037-01-01 00:00:00"}
        ]
}

  從上面配置能夠看出，時間在2004-01-01 00:00:00~2015-01-01 00:00:00的數據存放到bigtest_0的表中，時間在2015-01-01 00:00:01 ~2037-01-01 00:00:00的數據存放到bigtest_1的表中。

  在配置好pgoneproxy的proxy-part-tables選項後，啓動中間件pgoneproxy。進行表的建立，插入數據，查詢數據的操做，狀況以下所示：

1. 建立數據庫表

直接執行創表語句，pgoneproxy就會根據配置狀況自動建立兩張分表，狀況以下所示：

pgbench=> \dt;
              List of relations
 Schema |       Name       | Type  |  Owner   
--------+------------------+-------+----------
 public | pgbench_accounts | table | postgres
 public | pgbench_branches | table | postgres
 public | pgbench_history  | table | postgres
 public | pgbench_tellers  | table | postgres
(4 rows)

pgbench=> create table bigtest(id int, name varchar(1024), age int, tt timestamp);
CREATE 0
pgbench=> \dt;
              List of relations
 Schema |       Name       | Type  |  Owner   
--------+------------------+-------+----------
 public | bigtest_0        | table | db_user
 public | bigtest_1        | table | db_user
 public | pgbench_accounts | table | postgres
 public | pgbench_branches | table | postgres
 public | pgbench_history  | table | postgres
 public | pgbench_tellers  | table | postgres
(6 rows)

pgbench=>

2. 插入數據

下面插入兩條語句，看是否可以根據要求插入到不一樣的數據表中

pgbench=> select * from bigtest_0;
 id | name | age | tt 
----+------+-----+----
(0 rows)

pgbench=> select * from bigtest_1;
 id | name | age | tt 
----+------+-----+----
(0 rows)

pgbench=> insert into bigtest(id, name, age, tt) values (10, 'name10', 10, '2024-01-01 00:00:00');
INSERT 0 1
pgbench=> insert into bigtest(id, name, age, tt) values (10, 'name10', 10, '2014-01-01 00:00:00');
INSERT 0 1
pgbench=> select * from bigtest_0;
 id |  name  | age |         tt          
----+--------+-----+---------------------
 10 | name10 |  10 | 2014-01-01 00:00:00
(1 row)

pgbench=> select * from bigtest_1;
 id |  name  | age |         tt          
----+--------+-----+---------------------
 10 | name10 |  10 | 2024-01-01 00:00:00
(1 row)

pgbench=>

3. 查詢數據

根據各類條件進行數據查詢，狀況以下所示：

pgbench=> select * from bigtest where tt < '2015-01-01 00:00:00';
 id |  name  | age |         tt          
----+--------+-----+---------------------
 10 | name10 |  10 | 2014-01-01 00:00:00
(1 row)

pgbench=> select * from bigtest where tt > '2015-01-01 00:00:00';
 id |  name  | age |         tt          
----+--------+-----+---------------------
 10 | name10 |  10 | 2024-01-01 00:00:00
(1 row)

pgbench=> select * from bigtest where tt < '2035-01-01 00:00:00';
 id |  name  | age |         tt          
----+--------+-----+---------------------
 10 | name10 |  10 | 2014-01-01 00:00:00
 10 | name10 |  10 | 2024-01-01 00:00:00
(2 rows)

pgbench=> select * from bigtest where tt < '2035-01-01 00:00:00' and tt > '2016-01-01 00:00:00';
 id |  name  | age |         tt          
----+--------+-----+---------------------
 10 | name10 |  10 | 2024-01-01 00:00:00
(1 row)

則從上面的查詢狀況看，可以根據時間進行準確的查詢。故pgoneproxy也可以根據時間進行冷熱數據的分離存儲和查詢。