Postgres数据库truncate表无有效备份恢复---惜分飞

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标题：Postgres数据库truncate表无有效备份恢复

创建一个Postgres表,并插入数据

postgres=# CREATE TABLE "PeisInterfaceLog"(
postgres(#         "PeisInterfaceLogId" text,
postgres(#         "PeisDepartmentId" text,
postgres(#         "PeisDepartmentName" text,
postgres(#         "PeisInterfaceSubjectType" text,
postgres(#         "PeisInterfaceSubjectId" text,
postgres(#         "PeisInterfaceNo" text,
postgres(#         "PeisInterfaceName" text,
postgres(#         "PeisInterfaceDirection" text,
postgres(#         "PeisInterfaceCallAddress" text,
postgres(#         "PeisInterfaceLogStartTime" timestamp,
postgres(#         "PeisInterfaceInputContent" json,
postgres(#         "PeisInterfaceInputTranscodeContent" json,
postgres(#         "PeisInterfaceOutContent" json,
postgres(#         "PeisInterfaceOutTranscodeContent" json,
postgres(#         "PeisInterfaceSuccessSign" int4,
postgres(#         "PeisInterfaceLogStatusCode" text,
postgres(#         "PeisInterfaceLogNote" text,
postgres(#         "PeisInterfaceLogTimestamp" timestamp,
postgres(#         "PeisInterfaceLogInfo" text,
postgres(#         "PeisPatientRegisterId" text
postgres(# );
CREATE TABLE
postgres=# \i /postgres/COPY/public_copy.sql 
SET
COPY 722957
postgres=# select count(1) from "PeisInterfaceLog";
 count 
--------
 722957
(1 row)

验证truncate操作,引起Postgres中oid的变化

postgres=# checkpoint;
CHECKPOINT
postgres=#  show data_directory;
 data_directory 
----------------
 /pgdata
(1 row)
postgres=# select oid, datname from pg_database ;
  oid  |  datname  
-------+-----------
 13676 | postgres
     1 | template1
 13675 | template0
(3 rows)
postgres=# select relname, relowner, relfilenode from pg_class where relowner = 10 and relname like '%PeisInterfaceLog%';
     relname      | relowner | relfilenode 
------------------+----------+-------------
 PeisInterfaceLog |       10 |       16384
(1 row)
 
postgres=# truncate table "PeisInterfaceLog";
TRUNCATE TABLE
postgres=# select count(1) from  "PeisInterfaceLog";
 count
-------
     0
(1 row)
 
postgres=# select relname, relowner, relfilenode from pg_class where relowner = 10 and relname like '%PeisInterfaceLog%';
     relname      | relowner | relfilenode 
------------------+----------+-------------
 PeisInterfaceLog |       10 |       16394
(1 row)

使用工具进行初始化字典信息

PDU.public=# b;
 
开始初始化...
 -pg_database:</pgdata/global/1262>
 
数据库:postgres 
      -pg_schema:</pgdata/base/13676/2615>
      -pg_class:</pgdata/base/13676/1259> 共88行
      -pg_attribute:</pgdata/base/13676/1249> 共2950行
      模式:
        ▌ public 1张表
 
PDU.public=# use postgres;
 
┌────────────────────────────────────────┐
│          模式             │  表数量    │
├────────────────────────────────────────┤
│    public                 │  1         │
└────────────────────────────────────────┘
postgres.public=# set public;
 
┌──────────────────────────────────────────────────┐
│               表名                  │  表大小    │
├──────────────────────────────────────────────────┤
│    PeisInterfaceLog                 │  0         │
└──────────────────────────────────────────────────┘
        仅显示表大小排名前 1 的表名
postgres.public=# \d PeisInterfaceLog;
 
┌──────────────────────────────────────────────────────────────┐
│                            列类型                            │
└──────────────────────────────────────────────────────────────┘
text,text,text,text,text,text,text,text,text,timestamp,json,json,json,json,int4,text,text,timestamp,text,text

配置软件磁盘扫描操作（pdu.ini中配置）

#dropScan需要扫描的磁盘
DISK_PATH=/data/test.dd
#dropScan时跳跃的数据块数量，数值越小覆盖磁盘越全面，速度越慢
BLOCK_INTERVAL=5

启用磁盘扫描操作

PDU.public=# p idxmode off;
 
┌─────────────────────────────────────────────────────────────────┐
│              参数                │             当前值           │
├─────────────────────────────────────────────────────────────────┤
│    startwal                      │                              │
│    endwal                        │                              │
│    startlsnt                     │                              │
│    endlsnt                       │                              │
│    starttime                     │                              │
│    endtime                       │                              │
│    resmode(Data Restore Mode)    │              TIME            │
│    exmode(Data Export Mode)      │              CSV             │
│    encoding                      │              UTF8            │
│    restype(Data Restore Type)    │              DELETE          │
          ----------------------DropScan----------------------
│    dsoff(DropScan startOffset)   │              0               │
│    blkiter(Block Intervals)      │              5               │
│    itmpcsv(Items Per Csv)        │              100             │
│    idxmode                       │              off             │
└─────────────────────────────────────────────────────────────────┘
PDU.public=# ds;
 
 ▌全量扫描恢复模式 
 
 ▌数据文件扫描 
┌────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
          表名           │                                   结果                                    
├────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
 PeisInterfaceLog           99.976 %(21469593600)   数据页: 71158      成功: 722947    (疑似乱码: 2809      ) 失败: 0 
 
耗时 15.28 秒
└────────────────────────────────────────────────────────────────────────────────────────────────────┘
扫描完毕,文件目录如下: 
        restore/dropscan/PeisInterfaceLog
PDU.public=# ds copy;
已导出: 
/restore/dropscan/PeisInterfaceLog/COPY.sql
PDU.public=# 
 
[root@xifenfei PeisInterfaceLog]# more COPY.sql 
[root@xifenfei PeisInterfaceLog]# cat /restore/dropscan/PeisInterfaceLog/COPY.sql
COPY PeisInterfaceLog FROM '/restore/dropscan/PeisInterfaceLog/09-28-21:29:55_226738176_32760blks_336787items.csv';
COPY PeisInterfaceLog FROM '/restore/dropscan/PeisInterfaceLog/09-28-21:30:01_595968000_32767blks_330416items.csv';
COPY PeisInterfaceLog FROM '/restore/dropscan/PeisInterfaceLog/09-28-21:30:04_1116061696_5631blks_55744items.csv';

把恢复数据导入到Postgres数据中

[root@xifenfei ~]# su - postgres 
[postgres@xifenfei ~]$ psql
psql (12.8)
Type "help" for help.
 
postgres=# \i /restore/dropscan/PeisInterfaceLog/COPY.sql
COPY 336787
COPY 330416
COPY 55744
postgres=# select count(1) from "PeisInterfaceLog";
 count 
--------
 722947
(1 row)

经过上述扫描测试证明该工具实现了在Postgres中truncate数据的绝大部分数据恢复(这里的乱码不是由于没有扫描到数据,主要是由于个别字符串由于类型判断关系识别不对导致乱码抛弃).
如果你遇到Postgres 数据库由于drop/truncate等误操作，而且无有效备份进行恢复，面临数据丢失风险,请第一时间保护现场(数据文件所在分区尽可能不要有写入操作)，联系我们提供专业恢复技术支持:
电话/微信:17813235971 Q Q:107644445 E-Mail:dba@xifenfei.com