一restoredatabasepreview解释:官方说明:YoucanapplyRESTORE...PREVIEWtoanyRESTOREoperationtocreateadetailedlistofeverybackuptobeusedintherequestedRESTO
一 restore database preview 解释:
官方说明:
You can apply RESTORE ... PREVIEW to any RESTORE operation to create a detailed list of every backup to be used in the requested RESTORE operation, and the necessary target SCN for recovery after the RESTORE operation is complete. This command accesses the RMAN repository to query the backup metadata, but does not actually read the backup files to ensure that they can be restored.
上面大致说了两点:
2 restore………preview命令实际上不读取备份文件以确认备份能够恢复。
二:restore database preview 显示结果
RMAN> restore database preview;
Starting restore at 22-NOV-12
using channel ORA_DISK_1
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
5 Full 568.48M DISK 00:00:58 20-NOV-12
BP Key: 5 Status: AVAILABLE Compressed: NO Tag: TAG20121120T084422
Piece Name: /backup/07nqp236_1_1
List of Datafiles in backup set 5
File LV Type Ckp SCN Ckp Time Name
---- -- ---- ---------- --------- ----
1 Full 2150426643 20-NOV-12 /oracle/CRM2/system1.dbf
2 Full 2150426643 20-NOV-12 /oracle/CRM2/zxb.dbf
3 Full 2150426643 20-NOV-12 /oracle/CRM2/CRM/sysaux01.dbf
4 Full 2150426643 20-NOV-12 /oracle/CRM2/CRM/users01.dbf
5 Full 2150426643 20-NOV-12 /oracle/CRM2/zxa.dbf
6 Full 2150426643 20-NOV-12 /oracle/CRM2/CRM/test1.dbf
7 Full 2150426643 20-NOV-12 /oracle/CRM2/zxc.dbf
8 Full 2150426643 20-NOV-12 /oracle/CRM2/CRM/undotbs1.dbf
List of Archived Log Copies
Key Thrd Seq S Low Time Name
------- ---- ------- - --------- ----
35 1 2 A 20-NOV-12 /oracle/archive/1_2_799830099.dbf
36 1 3 A 20-NOV-12 /oracle/archive/1_3_799830099.dbf
37 1 4 A 20-NOV-12 /oracle/archive/1_4_799830099.dbf
38 1 5 A 20-NOV-12 /oracle/archive/1_5_799830099.dbf
39 1 6 A 20-NOV-12 /oracle/archive/1_6_799830099.dbf
40 1 7 A 20-NOV-12 /oracle/archive/1_7_799830099.dbf
41 1 8 A 20-NOV-12 /oracle/archive/1_8_799830099.dbf
42 1 9 A 21-NOV-12 /oracle/archive/1_9_799830099.dbf
43 1 10 A 21-NOV-12 /oracle/archive/1_10_799830099.dbf
44 1 11 A 21-NOV-12 /oracle/archive/1_11_799830099.dbf
45 1 12 A 21-NOV-12 /oracle/archive/1_12_799830099.dbf
46 1 13 A 21-NOV-12 /oracle/archive/1_13_799830099.dbf
47 1 14 A 21-NOV-12 /oracle/archive/1_14_799830099.dbf
48 1 15 A 22-NOV-12 /oracle/archive/1_15_799830099.dbf
49 1 16 A 22-NOV-12 /oracle/archive/1_16_799830099.dbf
50 1 17 A 22-NOV-12 /oracle/archive/1_17_799830099.dbf
51 1 18 A 22-NOV-12 /oracle/archive/1_18_799830099.dbf
52 1 19 A 22-NOV-12 /oracle/archive/1_19_799830099.dbf
53 1 20 A 22-NOV-12 /oracle/archive/1_20_799830099.dbf
54 1 21 A 22-NOV-12 /oracle/archive/1_21_799830099.dbf
55 1 22 A 22-NOV-12 /oracle/archive/1_22_799830099.dbf
56 1 23 A 22-NOV-12 /oracle/archive/1_23_799830099.dbf
57 1 24 A 22-NOV-12 /oracle/archive/1_24_799830099.dbf
58 1 25 A 22-NOV-12 /oracle/archive/1_25_799830099.dbf
59 1 26 A 22-NOV-12 /oracle/archive/1_26_799830099.dbf
60 1 27 A 22-NOV-12 /oracle/archive/1_27_799830099.dbf
Media recovery start SCN is 2150426643
Recovery must be done beyond SCN 2150426643 to clear data files fuzziness
Finished restore at 22-NOV-12
----------------------------------------------------------------------------------------
对于上面的信息的一点解释:
介质恢复的开始是2150426643:Media recovery start SCN is 2150426643
以及开始应用的归档文件seq 号2:/oracle/archive/1_2_799830099.dbf
都是由restore database后,数据文件头部信息决定,如下为转储数据文件头部信息:
Tablespace #2 - SYSAUX rel_fn:3
Creation at scn: 0x0000.00001896 10/22/2005 21:44:46
Backup taken at scn: 0x0000.00000000 01/01/1988 00:00:00 thread:0
reset logs count:0x2fac7053 scn: 0x0000.802c8c23 reset logs terminal rcv data:0x0 scn: 0x0000.00000000
prev reset logs count:0x2fac6f51 scn: 0x0000.802c3dfd prev reset logs terminal rcv data:0x0 scn: 0x0000.00000000
recovered at 11/22/2012 14:18:39
status:0x0 root dba:0x00000000 chkpt cnt: 1114 ctl cnt:1113
begin-hot-backup file size: 0

MySQLviewshavelimitations:1)Theydon'tsupportallSQLoperations,restrictingdatamanipulationthroughviewswithjoinsorsubqueries.2)Theycanimpactperformance,especiallywithcomplexqueriesorlargedatasets.3)Viewsdon'tstoredata,potentiallyleadingtooutdatedinforma

ProperusermanagementinMySQLiscrucialforenhancingsecurityandensuringefficientdatabaseoperation.1)UseCREATEUSERtoaddusers,specifyingconnectionsourcewith@'localhost'or@'%'.2)GrantspecificprivilegeswithGRANT,usingleastprivilegeprincipletominimizerisks.3)

MySQLdoesn'timposeahardlimitontriggers,butpracticalfactorsdeterminetheireffectiveuse:1)Serverconfigurationimpactstriggermanagement;2)Complextriggersincreasesystemload;3)Largertablesslowtriggerperformance;4)Highconcurrencycancausetriggercontention;5)M

Yes,it'ssafetostoreBLOBdatainMySQL,butconsiderthesefactors:1)StorageSpace:BLOBscanconsumesignificantspace,potentiallyincreasingcostsandslowingperformance.2)Performance:LargerrowsizesduetoBLOBsmayslowdownqueries.3)BackupandRecovery:Theseprocessescanbe

Adding MySQL users through the PHP web interface can use MySQLi extensions. The steps are as follows: 1. Connect to the MySQL database and use the MySQLi extension. 2. Create a user, use the CREATEUSER statement, and use the PASSWORD() function to encrypt the password. 3. Prevent SQL injection and use the mysqli_real_escape_string() function to process user input. 4. Assign permissions to new users and use the GRANT statement.

MySQL'sBLOBissuitableforstoringbinarydatawithinarelationaldatabase,whileNoSQLoptionslikeMongoDB,Redis,andCassandraofferflexible,scalablesolutionsforunstructureddata.BLOBissimplerbutcanslowdownperformancewithlargedata;NoSQLprovidesbetterscalabilityand

ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

Notepad++7.3.1
Easy-to-use and free code editor

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

SublimeText3 Mac version
God-level code editing software (SublimeText3)

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
