Question

我正在使用带有citus扩展名的Postgresql进行分片，并且无法像下面那样对表格进行分片。下表有一个主键和2个唯一键。我试图对主键的列进行分片，即pid。注意：我不允许更改表格结构。这些表由工具创建。

CREATE TABLE person 
(
    pid bigint NOT NULL,
    name character varying(100),
    address_pid bigint NOT NULL,
    address_type character varying(100),
    CONSTRAINT id_pkey PRIMARY KEY (pid),
    CONSTRAINT addr_id UNIQUE (address_pid),
    CONSTRAINT addr_type_id UNIQUE (address_type, address_pid)
);

这是我的分片查询：

select create_distributed_table('person', 'pid');

抛出的错误是：

Error: Distributed relations cannot have UNIQUE, EXCLUDE, or PRIMARY KEY constraints that do not include the partition column

任何人都可以帮我分类这些表吗？

@CraigKerstiens除了这个问题：

当我们有多个像这样的外键时，如何处理分片。

CREATE TABLE table
(
    pid bigint NOT NULL,
    search_order integer NOT NULL,
    resource_pid bigint NOT NULL,
    search_pid bigint NOT NULL,
    CONSTRAINT hfj_search_result_pkey PRIMARY KEY (pid),
    CONSTRAINT idx_searchres_order UNIQUE (search_pid, search_order),
    CONSTRAINT fk_searchres_res FOREIGN KEY (resource_pid)
        REFERENCES public.table1 (res_id) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION,
    CONSTRAINT fk_searchres_search FOREIGN KEY (search_pid)
        REFERENCES public.table2 (pid) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION
)

假设table1和table2已经分片。

Answer 1

此时，在Citus中，您不能拥有一个不包含您要分区的列的唯一约束。在这种情况下，可以强制执行人员ID唯一的地址，但不是全局唯一的。要做到这一点，你可以：

CREATE TABLE person 
(
    pid bigint NOT NULL,
    name character varying(100),
    address_pid bigint NOT NULL,
    address_type character varying(100),
    CONSTRAINT id_pkey PRIMARY KEY (pid),
    CONSTRAINT addr_id UNIQUE (pid, address_pid),
    CONSTRAINT addr_type_id UNIQUE (pid, address_type, address_pid)
);

postgresql分片与citus扩展无法正常工作

1 个答案: