热门标签 | HotTags
当前位置:  开发笔记 > 数据库 > 正文

OracleRMAN实现“一键式”表空间TSPITR

从Oracle10g之后,小规模数据误删除、误操作其实已经有了很好的解决方案,就是flashback技术。FlashbackQuery和FlashbackDrop

从Oracle 10g之后,小规模数据误删除、误操作其实已经有了很好的解决方案,就是flashback技术。Flashback Query和Flashback Drop

从Oracle 10g之后,小规模数据误删除、误操作其实已经有了很好的解决方案,就是flashback技术。Flashback Query和Flashback Drop,就可以从数据记录和数据表这类比较细的粒度。

在实际业务场景中,相对比“天塌地陷”的全库恢复场景,单Schema、单Tablespace甚至单数据表的局部恢复更加有施展的空间。出现误操作的时候,用户往往希望一个或者部分数据表恢复到过去的一个时间点。同时又不希望将全库恢复到过去时间,丢失部分数据。

RMAN提供了一种实现所谓TSPITR(Tablespace Point-In-Time Recovery)的技术,通过简单的一个语句,就可以在主库不停库(很吸引人)的情况下,利用备份集和连续的归档日志,实现表空间级别的定点恢复。

本篇主要介绍进行RMAN TSPITR操作的步骤方法和一些技术细节点,,供需要的朋友待查。

1、环境背景介绍

笔者选择Oracle 11g进行试验,具体版本为11.2.0.4版本。数据库模式为归档模式。

SQL> select * from v$version;

BANNER

--------------------------------------------------------------------------------

Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - Production

PL/SQL Release 11.2.0.4.0 - Production

CORE 11.2.0.4.0 Production

TNS for Linux: Version 11.2.0.4.0 - Production

NLSRTL Version 11.2.0.4.0 - Production

SQL> archive log list;

Database log mode Archive Mode

Automatic archival Enabled

Archive destination USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence 5

Next log sequence to archive 8

Current log sequence 8

尝试构建一个全新schema,在一个全新的tablespace中。实验数据选择scott用户的数据。

SQL> create tablespace testtbl datafile size 10m autoextend on extent management local uniform size 1m segment space management auto;

Tablespace created

SQL> create user test identified by test default tablespace testtbl;

User created

SQL> grant resource, connect to test;

Grant succeeded

使用之前导出的scott数据,进行remap导入。

[oracle@SimpleLinux ~]$ impdp \"/ as sysdba\" dumpfile=scott_20150618.dmp remap_schema=scott:test remap_tablespace=users:testtbl

Import: Release 11.2.0.4.0 - Production on Thu Jun 18 09:50:17 2015

Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - Production

With the Partitioning, Oracle Label Security, OLAP, Data Mining

and Real Application Testing options

Master table "SYS"."SYS_IMPORT_FULL_01" successfully loaded/unloaded

(篇幅原因,有省略……)

Processing object type SCHEMA_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT

Processing object type SCHEMA_EXPORT/POST_SCHEMA/PROCACT_SCHEMA

Job "SYS"."SYS_IMPORT_FULL_01" completed with 1 error(s) at Thu Jun 18 09:50:28 2015 elapsed 0 00:00:08

SQL> select owner ,tablespace_name, count(*) from dba_segments where owner='TEST' group by owner, tablespace_name;

OWNER TABLESPACE_NAME COUNT(*)

------------------------------ ------------------------------ ----------

TEST TESTTBL 5

两个数据表。

SQL> select count(*) from test.emp;

COUNT(*)

----------

14

SQL> select count(*) from test.dept;

COUNT(*)

----------

4

2、数据备份和故障发生

归档模式下,需要有一份完全的备份,才能实现恢复操作。

RMAN> backup database plus archivelog delete input;

Starting backup at 18-JUN-15

current log archived

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=47 device type=DISK

(篇幅原因,有省略…….)

Starting Control File and SPFILE Autobackup at 18-JUN-15

piece handle=/u01/app/fast_recovery_area/ORA11G/autobackup/2015_06_18/o1_mf_s_882701042_br4d3m3c_.bkp comment=NONE

Finished Control File and SPFILE Autobackup at 18-JUN-15

SQL> select group#, sequence# from v$log where status='CURRENT';

GROUP# SEQUENCE#

---------- ----------

2 17

此时,操作时间为:

SQL> select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') a from dual;

A

--------------------

2015-06-18 10:51:19

过了几个小时,误操作发生。

SQL> select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') a from dual;

A

--------------------

2015-06-18 13:47:29

SQL> select group#, sequence# from v$log where status='CURRENT';

GROUP# SEQUENCE#

---------- ----------

3 19

误删除发生

SQL> drop table test.emp;

Table dropped

SQL> drop table test.dept;

Table dropped

--Flashback Drop的机会也没有了。

SQL> purge dba_recyclebin;

Done

3、RMAN进行表空间TSPITR

单表表空间移动,要确保表空间内容“内包”,也就是不会有其他表空间牵扯其中。这个操作我们在可移动表空间的演示中也会进行。

SQL> exec dbms_tts.transport_set_check('testtbl',true);

PL/SQL procedure successfully completed

SQL> select * from transport_set_violations;

VIOLATIONS

--------------------------------------------------------------------------------

下面进行实际恢复操作,首先需要在目录中创建出一个可访问的空间,进行临时文件容纳。

[root@SimpleLinux ~]# cd /

[root@SimpleLinux /]# mkdir -p /extend/oradata/aux

[root@SimpleLinux /]# chown -R oracle:oinstall /extend/

[root@SimpleLinux /]# ls -l | grep extend

drwxr-xr-x. 3 oracle oinstall 4096 Jun 18 10:21 extend

启动RMAN,登录后执行recover tablespace操作,指定出恢复时间。注意:RMAN的recover tablespace命令本质上是执行一系列的指令脚本,将利用RMAN恢复过程自动化,无需人工介入。

[oracle@SimpleLinux ~]$ rman nocatalog

Recovery Manager: Release 11.2.0.4.0 - Production on Thu Jun 18 13:48:44 2015

Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.

RMAN> connect target /

connected to target database: ORA11G (DBID=4239941846)

using target database control file instead of recovery catalog

RMAN> recover tablespace testtbl until time "to_date('2015-06-18 10:51:19','yyyy-mm-dd hh24:mi:ss')" auxiliary destination '/extend/oradata/aux';

Starting recover at 18-JUN-15

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=44 device type=DISK

RMAN-05026: WARNING: presuming following set of tablespaces applies to specified point-in-time

List of tablespaces expected to have UNDO segments

Tablespace SYSTEM

Tablespace UNDOTBS1

Creating automatic instance, with SID='DDfe' –在目录中创建出一个虚拟的Oracle实例

--启动实例的参数都准备好了。

initialization parameters used for automatic instance:

db_name=ORA11G

db_unique_name=DDfe_tspitr_ORA11G

compatible=11.2.0.4.0

db_block_size=8192

db_files=200

sga_target=1G

processes=80

db_create_file_dest=/extend/oradata/aux

log_archive_dest_1='location=/extend/oradata/aux'

#No auxiliary parameter file used

starting up automatic instance ORA11G

Oracle instance started

Total System Global Area 1071333376 bytes

Fixed Size 1369420 bytes

Variable Size 281021108 bytes

Database Buffers 784334848 bytes

Redo Buffers 4608000 bytes

Automatic instance created

--自包检查

Running TRANSPORT_SET_CHECK on recovery set tablespaces

TRANSPORT_SET_CHECK completed successfully

--第一块脚本片段,利用备份集合和归档日志,恢复数据到虚拟实例上。

contents of Memory Script:

{

# set requested point in time

set until time "to_date('2015-06-18 10:51:19','yyyy-mm-dd hh24:mi:ss')";

# restore the controlfile

restore clone controlfile;

# mount the controlfile

sql clone 'alter database mount clone database';

# archive current online log

sql 'alter system archive log current';

# avoid unnecessary autobackups for structural changes during TSPITR

sql 'begin dbms_backup_restore.AutoBackupFlag(FALSE); end;';

}

executing Memory Script

executing command: SET until clause

Starting restore at 18-JUN-15

allocated channel: ORA_AUX_DISK_1

channel ORA_AUX_DISK_1: SID=19 device type=DISK

channel ORA_AUX_DISK_1: starting datafile backup set restore

channel ORA_AUX_DISK_1: restoring control file

channel ORA_AUX_DISK_1: reading from backup piece /u01/app/fast_recovery_area/ORA11G/autobackup/2015_06_18/o1_mf_s_882701042_br4d3m3c_.bkp

channel ORA_AUX_DISK_1: piece handle=/u01/app/fast_recovery_area/ORA11G/autobackup/2015_06_18/o1_mf_s_882701042_br4d3m3c_.bkp tag=TAG20150618T104402

channel ORA_AUX_DISK_1: restored backup piece 1

channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:02

output file name=/extend/oradata/aux/ORA11G/controlfile/o1_mf_br4q1v2o_.ctl

Finished restore at 18-JUN-15

sql statement: alter database mount clone database

sql statement: alter system archive log current

sql statement: begin dbms_backup_restore.AutoBackupFlag(FALSE); end;

contents of Memory Script:

{

# set requested point in time

set until time "to_date('2015-06-18 10:51:19','yyyy-mm-dd hh24:mi:ss')";

plsql <<<-- tspitr_2

declare

sqlstatement varchar2(512);

offline_not_needed exception;

pragma exception_init(offline_not_needed, -01539);

begin

sqlstatement := 'alter tablespace '|| 'TESTTBL' ||' offline immediate';

krmicd.writeMsg(6162, sqlstatement);

krmicd.execSql(sqlstatement);

exception

when offline_not_needed then

null;

end; >>>;

# set destinations for recovery set and auxiliary set datafiles

set newname for clone datafile 1 to new;

set newname for clone datafile 5 to new;

set newname for clone datafile 3 to new;

set newname for clone datafile 2 to new;

set newname for clone tempfile 1 to new;

set newname for datafile 7 to

"/u01/app/oradata/ORA11G/datafile/o1_mf_testtbl_br48h8wp_.dbf";

# switch all tempfiles

switch clone tempfile all;

# restore the tablespaces in the recovery set and the auxiliary set

restore clone datafile 1, 5, 3, 2, 7;

switch clone datafile all;

}

executing Memory Script

executing command: SET until clause

sql statement: alter tablespace TESTTBL offline immediate

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

renamed tempfile 1 to /extend/oradata/aux/ORA11G/datafile/o1_mf_temp_%u_.tmp in control file

Starting restore at 18-JUN-15

using channel ORA_AUX_DISK_1

--只恢复system, sysaux, undo和目标testtbl表空间。

channel ORA_AUX_DISK_1: starting datafile backup set restore

channel ORA_AUX_DISK_1: specifying datafile(s) to restore from backup set

channel ORA_AUX_DISK_1: restoring datafile 00001 to /extend/oradata/aux/ORA11G/datafile/o1_mf_system_%u_.dbf

channel ORA_AUX_DISK_1: restoring datafile 00005 to /extend/oradata/aux/ORA11G/datafile/o1_mf_system_%u_.dbf

channel ORA_AUX_DISK_1: restoring datafile 00003 to /extend/oradata/aux/ORA11G/datafile/o1_mf_undotbs1_%u_.dbf

channel ORA_AUX_DISK_1: restoring datafile 00002 to /extend/oradata/aux/ORA11G/datafile/o1_mf_sysaux_%u_.dbf

channel ORA_AUX_DISK_1: restoring datafile 00007 to /u01/app/oradata/ORA11G/datafile/o1_mf_testtbl_br48h8wp_.dbf

channel ORA_AUX_DISK_1: reading from backup piece /u01/app/fast_recovery_area/ORA11G/backupset/2015_06_18/o1_mf_nnndf_TAG20150618T104315_br4d23ty_.bkp

channel ORA_AUX_DISK_1: piece handle=/u01/app/fast_recovery_area/ORA11G/backupset/2015_06_18/o1_mf_nnndf_TAG20150618T104315_br4d23ty_.bkp tag=TAG20150618T104315

channel ORA_AUX_DISK_1: restored backup piece 1

channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:01:05

Finished restore at 18-JUN-15

datafile 1 switched to datafile copy

input datafile copy RECID=5 STAMP=882712324 file name=/extend/oradata/aux/ORA11G/datafile/o1_mf_system_br4q22sy_.dbf

datafile 5 switched to datafile copy

input datafile copy RECID=6 STAMP=882712324 file name=/extend/oradata/aux/ORA11G/datafile/o1_mf_system_br4q230g_.dbf

datafile 3 switched to datafile copy

input datafile copy RECID=7 STAMP=882712324 file name=/extend/oradata/aux/ORA11G/datafile/o1_mf_undotbs1_br4q22z4_.dbf

datafile 2 switched to datafile copy

input datafile copy RECID=8 STAMP=882712324 file name=/extend/oradata/aux/ORA11G/datafile/o1_mf_sysaux_br4q22yx_.dbf

--启动虚拟实例数据,完成恢复。

contents of Memory Script:

{

# set requested point in time

set until time "to_date('2015-06-18 10:51:19','yyyy-mm-dd hh24:mi:ss')";

# online the datafiles restored or switched

sql clone "alter database datafile 1 online";

sql clone "alter database datafile 5 online";

sql clone "alter database datafile 3 online";

sql clone "alter database datafile 2 online";

sql clone "alter database datafile 7 online";

# recover and open resetlogs

recover clone database tablespace "TESTTBL", "SYSTEM", "UNDOTBS1", "SYSAUX" delete archivelog;

alter clone database open resetlogs;

}

executing Memory Script

executing command: SET until clause

sql statement: alter database datafile 1 online

sql statement: alter database datafile 5 online

sql statement: alter database datafile 3 online

sql statement: alter database datafile 2 online

sql statement: alter database datafile 7 online

Starting recover at 18-JUN-15

using channel ORA_AUX_DISK_1

starting media recovery

archived log for thread 1 with sequence 17 is already on disk as file /u01/app/fast_recovery_area/ORA11G/archivelog/2015_06_18/o1_mf_1_17_br4pw26f_.arc

channel ORA_AUX_DISK_1: starting archived log restore to default destination

channel ORA_AUX_DISK_1: restoring archived log

archived log thread=1 sequence=16

channel ORA_AUX_DISK_1: reading from backup piece /u01/app/fast_recovery_area/ORA11G/backupset/2015_06_18/o1_mf_annnn_TAG20150618T104401_br4d3k9f_.bkp

channel ORA_AUX_DISK_1: piece handle=/u01/app/fast_recovery_area/ORA11G/backupset/2015_06_18/o1_mf_annnn_TAG20150618T104401_br4d3k9f_.bkp tag=TAG20150618T104401

channel ORA_AUX_DISK_1: restored backup piece 1

channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:01

archived log file name=/extend/oradata/aux/1_16_846081044.dbf thread=1 sequence=16

channel clone_default: deleting archived log(s)

archived log file name=/extend/oradata/aux/1_16_846081044.dbf RECID=27 STAMP=882712328

archived log file name=/u01/app/fast_recovery_area/ORA11G/archivelog/2015_06_18/o1_mf_1_17_br4pw26f_.arc thread=1 sequence=17

media recovery complete, elapsed time: 00:00:01

Finished recover at 18-JUN-15

database opened

--将表空间导出来

contents of Memory Script:

{

# make read only the tablespace that will be exported

sql clone 'alter tablespace TESTTBL read only';

# create directory for datapump import

sql "create or replace directory TSPITR_DIROBJ_DPDIR as ''

/extend/oradata/aux''";

# create directory for datapump export

sql clone "create or replace directory TSPITR_DIROBJ_DPDIR as ''

/extend/oradata/aux''";

}

executing Memory Script

sql statement: alter tablespace TESTTBL read only

sql statement: create or replace directory TSPITR_DIROBJ_DPDIR as ''/extend/oradata/aux''

sql statement: create or replace directory TSPITR_DIROBJ_DPDIR as ''/extend/oradata/aux''

Performing export of metadata...

EXPDP> Starting "SYS"."TSPITR_EXP_DDfe":

EXPDP> Processing object type TRANSPORTABLE_EXPORT/PLUGTS_BLK

EXPDP> Processing object type TRANSPORTABLE_EXPORT/TABLE

EXPDP> Processing object type TRANSPORTABLE_EXPORT/INDEX/INDEX

EXPDP> Processing object type TRANSPORTABLE_EXPORT/CONSTRAINT/CONSTRAINT

EXPDP> Processing object type TRANSPORTABLE_EXPORT/INDEX_STATISTICS

EXPDP> Processing object type TRANSPORTABLE_EXPORT/CONSTRAINT/REF_CONSTRAINT

EXPDP> Processing object type TRANSPORTABLE_EXPORT/POST_INSTANCE/PLUGTS_BLK

EXPDP> Master table "SYS"."TSPITR_EXP_DDfe" successfully loaded/unloaded

EXPDP> ******************************************************************************

EXPDP> Dump file set for SYS.TSPITR_EXP_DDfe is:

EXPDP> /extend/oradata/aux/tspitr_DDfe_54026.dmp

EXPDP> ******************************************************************************

EXPDP> Datafiles required for transportable tablespace TESTTBL:

EXPDP> /u01/app/oradata/ORA11G/datafile/o1_mf_testtbl_br48h8wp_.dbf

EXPDP> Job "SYS"."TSPITR_EXP_DDfe" successfully completed at Thu Jun 18 13:54:10 2015 elapsed 0 00:01:13

Export completed

--关闭虚拟实例

contents of Memory Script:

{

# shutdown clone before import

shutdown clone immediate

# drop target tablespaces before importing them back

sql 'drop tablespace TESTTBL including contents keep datafiles cascade constraints';

}

executing Memory Script

database closed

database dismounted

Oracle instance shut down

--把原来的表空间删除掉

sql statement: drop tablespace TESTTBL including contents keep datafiles cascade constraints

--恢复导入数据

Performing import of metadata...

IMPDP> Master table "SYS"."TSPITR_IMP_DDfe" successfully loaded/unloaded

IMPDP> Starting "SYS"."TSPITR_IMP_DDfe":

IMPDP> Processing object type TRANSPORTABLE_EXPORT/PLUGTS_BLK

IMPDP> Processing object type TRANSPORTABLE_EXPORT/TABLE

IMPDP> Processing object type TRANSPORTABLE_EXPORT/INDEX/INDEX

IMPDP> Processing object type TRANSPORTABLE_EXPORT/CONSTRAINT/CONSTRAINT

IMPDP> Processing object type TRANSPORTABLE_EXPORT/INDEX_STATISTICS

IMPDP> Processing object type TRANSPORTABLE_EXPORT/CONSTRAINT/REF_CONSTRAINT

IMPDP> Processing object type TRANSPORTABLE_EXPORT/POST_INSTANCE/PLUGTS_BLK

IMPDP> Job "SYS"."TSPITR_IMP_DDfe" successfully completed at Thu Jun 18 13:54:54 2015 elapsed 0 00:00:10

Import completed

--第三部分脚本,恢复表空间

contents of Memory Script:

{

# make read write and offline the imported tablespaces

sql 'alter tablespace TESTTBL read write';

sql 'alter tablespace TESTTBL offline';

# enable autobackups after TSPITR is finished

sql 'begin dbms_backup_restore.AutoBackupFlag(TRUE); end;';

}

executing Memory Script

sql statement: alter tablespace TESTTBL read write

sql statement: alter tablespace TESTTBL offline

sql statement: begin dbms_backup_restore.AutoBackupFlag(TRUE); end;

Removing automatic instance

Automatic instance removed

auxiliary instance file /extend/oradata/aux/ORA11G/datafile/o1_mf_temp_br4q4ojl_.tmp deleted

auxiliary instance file /extend/oradata/aux/ORA11G/onlinelog/o1_mf_4_br4q4j17_.log deleted

auxiliary instance file /extend/oradata/aux/ORA11G/onlinelog/o1_mf_3_br4q4ghl_.log deleted

auxiliary instance file /extend/oradata/aux/ORA11G/onlinelog/o1_mf_2_br4q4dt5_.log deleted

auxiliary instance file /extend/oradata/aux/ORA11G/onlinelog/o1_mf_1_br4q4brh_.log deleted

auxiliary instance file /extend/oradata/aux/ORA11G/datafile/o1_mf_sysaux_br4q22yx_.dbf deleted

auxiliary instance file /extend/oradata/aux/ORA11G/datafile/o1_mf_undotbs1_br4q22z4_.dbf deleted

auxiliary instance file /extend/oradata/aux/ORA11G/datafile/o1_mf_system_br4q230g_.dbf deleted

auxiliary instance file /extend/oradata/aux/ORA11G/datafile/o1_mf_system_br4q22sy_.dbf deleted

auxiliary instance file /extend/oradata/aux/ORA11G/controlfile/o1_mf_br4q1v2o_.ctl deleted

Finished recover at 18-JUN-15

RMAN>

上面的步骤可以归纳为如下:

ü 在目录中创建一个虚拟临时数据库实例;

ü RMAN自动辅助库AUX创建,利用源数据库的备份集合和归档日志进行全库不完全恢复。恢复范围包括system、sysaux、undo和目标表空间;

ü 借助Expdp和Impdp,使用可移动表空间原理步骤,将目标表空间数据导出并导回源数据库;

ü 恢复完成;

下面可以看实际效果。

SQL> select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') a from dual;

A

--------------------

2015-06-18 13:55:43

SQL> select group#, sequence# from v$log where status='CURRENT';

GROUP# SEQUENCE#

---------- ----------

1 20

尝试访问数据表。

SQL> select count(*) from test.emp;

select count(*) from test.emp

ORA-00376: 无法读取数据文件 7

ORA-01110: 数据文件 7: '/u01/app/oradata/ORA11G/datafile/o1_mf_testtbl_br48h8wp_.dbf'

此时,表空间被offline,需要手工进行online操作。

SQL> select tablespace_name, status from dba_tablespaces;

TABLESPACE_NAME STATUS

------------------------------ ---------

SYSTEM ONLINE

SYSAUX ONLINE

UNDOTBS1 ONLINE

TEMP ONLINE

USERS ONLINE

TESTTBL OFFLINE

6 rows selected

SQL> alter tablespace testtbl online;

Tablespace altered

SQL> select tablespace_name, status from dba_tablespaces;

TABLESPACE_NAME STATUS

------------------------------ ---------

SYSTEM ONLINE

SYSAUX ONLINE

UNDOTBS1 ONLINE

TEMP ONLINE

USERS ONLINE

TESTTBL ONLINE

6 rows selected

SQL> select count(*) from test.emp;

COUNT(*)

----------

14

SQL> select count(*) from test.dept;

COUNT(*)

----------

4

5、结论

推荐阅读
  • 一、Hadoop来历Hadoop的思想来源于Google在做搜索引擎的时候出现一个很大的问题就是这么多网页我如何才能以最快的速度来搜索到,由于这个问题Google发明 ... [详细]
  • 本文介绍了Oracle数据库中tnsnames.ora文件的作用和配置方法。tnsnames.ora文件在数据库启动过程中会被读取,用于解析LOCAL_LISTENER,并且与侦听无关。文章还提供了配置LOCAL_LISTENER和1522端口的示例,并展示了listener.ora文件的内容。 ... [详细]
  • 本文详细介绍了在ASP.NET中获取插入记录的ID的几种方法,包括使用SCOPE_IDENTITY()和IDENT_CURRENT()函数,以及通过ExecuteReader方法执行SQL语句获取ID的步骤。同时,还提供了使用这些方法的示例代码和注意事项。对于需要获取表中最后一个插入操作所产生的ID或马上使用刚插入的新记录ID的开发者来说,本文提供了一些有用的技巧和建议。 ... [详细]
  • 本文讨论了在数据库打开和关闭状态下,重新命名或移动数据文件和日志文件的情况。针对性能和维护原因,需要将数据库文件移动到不同的磁盘上或重新分配到新的磁盘上的情况,以及在操作系统级别移动或重命名数据文件但未在数据库层进行重命名导致报错的情况。通过三个方面进行讨论。 ... [详细]
  • android listview OnItemClickListener失效原因
    最近在做listview时发现OnItemClickListener失效的问题,经过查找发现是因为button的原因。不仅listitem中存在button会影响OnItemClickListener事件的失效,还会导致单击后listview每个item的背景改变,使得item中的所有有关焦点的事件都失效。本文给出了一个范例来说明这种情况,并提供了解决方法。 ... [详细]
  • Windows下配置PHP5.6的方法及注意事项
    本文介绍了在Windows系统下配置PHP5.6的步骤及注意事项,包括下载PHP5.6、解压并配置IIS、添加模块映射、测试等。同时提供了一些常见问题的解决方法,如下载缺失的msvcr110.dll文件等。通过本文的指导,读者可以轻松地在Windows系统下配置PHP5.6,并解决一些常见的配置问题。 ... [详细]
  • 本文介绍了在Win10上安装WinPythonHadoop的详细步骤,包括安装Python环境、安装JDK8、安装pyspark、安装Hadoop和Spark、设置环境变量、下载winutils.exe等。同时提醒注意Hadoop版本与pyspark版本的一致性,并建议重启电脑以确保安装成功。 ... [详细]
  • 使用在线工具jsonschema2pojo根据json生成java对象
    本文介绍了使用在线工具jsonschema2pojo根据json生成java对象的方法。通过该工具,用户只需将json字符串复制到输入框中,即可自动将其转换成java对象。该工具还能解析列表式的json数据,并将嵌套在内层的对象也解析出来。本文以请求github的api为例,展示了使用该工具的步骤和效果。 ... [详细]
  • 如何在服务器主机上实现文件共享的方法和工具
    本文介绍了在服务器主机上实现文件共享的方法和工具,包括Linux主机和Windows主机的文件传输方式,Web运维和FTP/SFTP客户端运维两种方式,以及使用WinSCP工具将文件上传至Linux云服务器的操作方法。此外,还介绍了在迁移过程中需要安装迁移Agent并输入目的端服务器所在华为云的AK/SK,以及主机迁移服务会收集的源端服务器信息。 ... [详细]
  • imx6ull开发板驱动MT7601U无线网卡的方法和步骤详解
    本文详细介绍了在imx6ull开发板上驱动MT7601U无线网卡的方法和步骤。首先介绍了开发环境和硬件平台,然后说明了MT7601U驱动已经集成在linux内核的linux-4.x.x/drivers/net/wireless/mediatek/mt7601u文件中。接着介绍了移植mt7601u驱动的过程,包括编译内核和配置设备驱动。最后,列举了关键词和相关信息供读者参考。 ... [详细]
  • Linux环境变量函数getenv、putenv、setenv和unsetenv详解
    本文详细解释了Linux中的环境变量函数getenv、putenv、setenv和unsetenv的用法和功能。通过使用这些函数,可以获取、设置和删除环境变量的值。同时给出了相应的函数原型、参数说明和返回值。通过示例代码演示了如何使用getenv函数获取环境变量的值,并打印出来。 ... [详细]
  • 成功安装Sabayon Linux在thinkpad X60上的经验分享
    本文分享了作者在国庆期间在thinkpad X60上成功安装Sabayon Linux的经验。通过修改CHOST和执行emerge命令,作者顺利完成了安装过程。Sabayon Linux是一个基于Gentoo Linux的发行版,可以将电脑快速转变为一个功能强大的系统。除了作为一个live DVD使用外,Sabayon Linux还可以被安装在硬盘上,方便用户使用。 ... [详细]
  • Android源码深入理解JNI技术的概述和应用
    本文介绍了Android源码中的JNI技术,包括概述和应用。JNI是Java Native Interface的缩写,是一种技术,可以实现Java程序调用Native语言写的函数,以及Native程序调用Java层的函数。在Android平台上,JNI充当了连接Java世界和Native世界的桥梁。本文通过分析Android源码中的相关文件和位置,深入探讨了JNI技术在Android开发中的重要性和应用场景。 ... [详细]
  • 在CentOS/RHEL 7/6,Fedora 27/26/25上安装JAVA 9的步骤和方法
    本文介绍了在CentOS/RHEL 7/6,Fedora 27/26/25上安装JAVA 9的详细步骤和方法。首先需要下载最新的Java SE Development Kit 9发行版,然后按照给出的Shell命令行方式进行安装。详细的步骤和方法请参考正文内容。 ... [详细]
  • Linux如何安装Mongodb的详细步骤和注意事项
    本文介绍了Linux如何安装Mongodb的详细步骤和注意事项,同时介绍了Mongodb的特点和优势。Mongodb是一个开源的数据库,适用于各种规模的企业和各类应用程序。它具有灵活的数据模式和高性能的数据读写操作,能够提高企业的敏捷性和可扩展性。文章还提供了Mongodb的下载安装包地址。 ... [详细]
author-avatar
zhangpingzizai
这个家伙很懒,什么也没留下!
PHP1.CN | 中国最专业的PHP中文社区 | DevBox开发工具箱 | json解析格式化 |PHP资讯 | PHP教程 | 数据库技术 | 服务器技术 | 前端开发技术 | PHP框架 | 开发工具 | 在线工具
Copyright © 1998 - 2020 PHP1.CN. All Rights Reserved | 京公网安备 11010802041100号 | 京ICP备19059560号-4 | PHP1.CN 第一PHP社区 版权所有