pg_catalog 表损坏时如何创建备份文件？

问题描述

我使用 postgresql 9.6。 我尝试用 pg_dump 创建一个备份文件： pg_dump -U postgres -O -f file.backup database

但是我得到了错误： sql 错误 [XX000]：错误：无法读取文件“base/16393/1249”中的块 270：参数无效

使用此查询：

select
    c.tableoid,c.oid,c.relname,(
    select
        pg_catalog.array_agg(acl
    order by
        row_n)
    from
        (
        select
            acl,row_n
        from
            pg_catalog.unnest(coalesce(c.relacl,pg_catalog.acldefault(case when c.relkind = 'S' then 's' else 'r' end::"char",c.relowner))) with ordinality as perm(acl,row_n)
        where
            not exists (
            select
                1
            from
                pg_catalog.unnest(coalesce(pip.initprivs,c.relowner))) as init(init_acl)
            where
                acl = init_acl)) as foo) as relacl,row_n
        from
            pg_catalog.unnest(coalesce(pip.initprivs,c.relowner))) with ordinality as initp(acl,row_n)
        where
            not exists (
            select
                1
            from
                pg_catalog.unnest(coalesce(c.relacl,c.relowner))) as permp(orig_acl)
            where
                acl = orig_acl)) as foo) as rrelacl,null as initrelacl,null as initrrelacl,c.relkind,c.relnamespace,(
    select
        rolname
    from
        pg_catalog.pg_roles
    where
        oid = c.relowner) as rolname,c.relchecks,c.relhastriggers,c.relhasindex,c.relhasrules,c.relhasoids,c.relrowsecurity,c.relforcerowsecurity,c.relfrozenxid,c.relminmxid,tc.oid as toid,tc.relfrozenxid as tfrozenxid,tc.relminmxid as tminmxid,c.relpersistence,c.relispopulated,c.relreplident,c.relpages,case
        when c.reloftype <> 0 then c.reloftype::pg_catalog.regtype
        else null
    end as reloftype,d.refobjid as owning_tab,d.refobjsubid as owning_col,(
    select
        spcname
    from
        pg_tablespace t
    where
        t.oid = c.reltablespace) as reltablespace,array_remove(array_remove(c.reloptions,'check_option=local'),'check_option=cascaded') as reloptions,case
        when 'check_option=local' = any (c.reloptions) then 'LOCAL'::text
        when 'check_option=cascaded' = any (c.reloptions) then 'CASCADED'::text
        else null
    end as checkoption,tc.reloptions as toast_reloptions,exists (
    select
        1
    from
        pg_attribute at
    left join pg_init_privs pip on
        (c.oid = pip.objoid
        and pip.classoid = 'pg_class'::regclass
        and pip.objsubid = at.attnum)
        where at.attrelid = c.oid
        and ((
        select
            pg_catalog.array_agg(acl
        order by
            row_n)
        from
            (
            select
                acl,row_n
            from
                pg_catalog.unnest(coalesce(at.attacl,pg_catalog.acldefault('c',row_n)
            where
                not exists (
                select
                    1
                from
                    pg_catalog.unnest(coalesce(pip.initprivs,c.relowner))) as init(init_acl)
                where
                    acl = init_acl)) as foo) is not null
        or (
        select
            pg_catalog.array_agg(acl
        order by
            row_n)
        from
            (
            select
                acl,row_n
            from
                pg_catalog.unnest(coalesce(pip.initprivs,row_n)
            where
                not exists (
                select
                    1
                from
                    pg_catalog.unnest(coalesce(at.attacl,c.relowner))) as permp(orig_acl)
                where
                    acl = orig_acl)) as foo) is not null
        or null is not null
        or null is not null))as changed_acl
from
    pg_class c
left join pg_depend d on
    (c.relkind = 'S'
    and d.classid = c.tableoid
    and d.objid = c.oid
    and d.objsubid = 0
    and d.refclassid = c.tableoid
    and d.deptype = 'a')
left join pg_class tc on
    (c.reltoastrelid = tc.oid)
left join pg_init_privs pip on
    (c.oid = pip.objoid
    and pip.classoid = 'pg_class'::regclass
    and pip.objsubid = 0)
where
    c.relkind in ('r','S','v','c','m','f')
order by
    c.oid;

我认为某些表已损坏。有没有办法让我在不经过此查询的情况下创建备份？

解决方法

您的 pg_attribute 表中有数据损坏。该表包含所有数据库表、索引、复合类型等的列定义。

检查 base/16393/1249 的大小是否大于 2220032 字节（271 个块）。

您应该恢复备份。如果你没有备份，要么聘请一位 PostgreSQL 专家，他可能能够从坏块中提取信息，或者减少损失。