Kompyuter injiniringi” fakulteti ats 20-07 guruh talabasi isroilov Sarvarning

Qayta tiklash vositalari
Har bir DBMS qayta tiklash mexanizmiga yordam berish uchun quyidagi imkoniyatlarni taqdim etishi kerak:

• 
  Zaxiralash mexanizmi ma'lumotlar bazasi uchun ma'lum bir vaqt oralig'ida zaxira nusxalarini yaratadi.
  
• 
  Ro'yxatga olish vositalari tranzaktsiyalarning joriy holatini va ma'lumotlar bazasiga kiritilgan har qanday o'zgarishlarni kuzatib boradi.
  
• 
  Tekshirish punkti qurilmasi so'nggi yamoqlarni doimiy qilish va zaiflikdan himoya qilish uchun ma'lumotlar bazasini yangilash imkonini beradi.
  
• 
  Qayta tiklash menejeri ma'lumotlar bazasi tizimiga ma'lumotlar bazasini har qanday nosozlikdan keyin ishonchli va barqaror holatga qaytarish imkonini beradi.
  

Butun DBMS juda murakkab tuzilma bo'lib, har soniyada bir nechta tranzaktsiyalar amalga oshiriladi va amalga oshiriladi. Tizimning mustahkamligi va mustahkamligi nafaqat tizimning murakkab va xavfsiz arxitekturasiga, balki eng yomon holatlarda ma'lumotlarni boshqarish va saqlash usuliga ham bog'liq. Agar asosiy arxitektura ishlamay qolsa yoki ishlamay qolsa, tranzaktsiya paytida yo'qolgan ma'lumotlarni qayta tiklash uchun ba'zi usullar va protseduralar bo'lishi kerak.

SQL Server
Bu buyruq quyidagi tiklash stsenariylarini ishga tushirish imkonini beradi.

• 
  Ma'lumotlar bazasini to'liq zaxiradan tiklash (to'liq tiklash).
  
• 
  Ma'lumotlar bazasining bir qismini tiklash (qisman tiklash).
  
• 
  Muayyan fayllarni yoki fayl guruhlarini ma'lumotlar bazasiga tiklash (faylni tiklash).
  
• 
  Ma'lumotlar bazasidagi ma'lum sahifalarni tiklash (sahifalarni tiklash).
  
• 
  Tranzaktsiyalar jurnalini ma'lumotlar bazasiga tiklang (tranzaksiya jurnalini tiklash).
  
• 
  Ma'lumotlar bazasini ma'lumotlar bazasi surati olingan vaqtga qaytaring.
  

Sintaksis
Argumentlar haqida qo'shimcha ma'lumot olish uchun bayonot argumentlarini RESTORE (Transact-SQL) ga qarang .

--To Restore an Entire Database from a Full database backup (a Complete Restore):
RESTORE DATABASE { database_name | @database_name_var }
[ FROM [ ,...n ] ]
[ WITH
{
[ RECOVERY | NORECOVERY | STANDBY =
{standby_file_name | @standby_file_name_var }
]
| , [ ,...n ]
| ,
| ,
| ,
| ,
| , \

} [ ,...n ]
]
[;]


--To perform the first step of the initial restore sequence of a piecemeal restore:
RESTORE DATABASE { database_name | @database_name_var }
[ ,...n ]
[ FROM [ ,...n ] ]
WITH
PARTIAL, NORECOVERY
[ , [ ,...n ]
| , \

] [ ,...n ]
[;]


--To Restore Specific Files or Filegroups:
RESTORE DATABASE { database_name | @database_name_var }
[ ,...n ]
[ FROM [ ,...n ] ]
WITH
{
[ RECOVERY | NORECOVERY ]
[ , [ ,...n ] ]
} [ ,...n ]
[;]


--To Restore Specific Pages:
RESTORE DATABASE { database_name | @database_name_var }
PAGE = 'file:page [ ,...n ]'
[ , ] [ ,...n ]
[ FROM [ ,...n ] ]
WITH
NORECOVERY
[ , [ ,...n ] ]
[;]


--To Restore a Transaction Log:
RESTORE LOG { database_name | @database_name_var }
[ [ ,...n ] ]
[ FROM [ ,...n ] ]
[ WITH
{
[ RECOVERY | NORECOVERY | STANDBY =
{standby_file_name | @standby_file_name_var }
]
| , [ ,...n ]
| ,
| , \

} [ ,...n ]
]
[;]


--To Revert a Database to a Database Snapshot:
RESTORE DATABASE { database_name | @database_name_var }
FROM DATABASE_SNAPSHOT = database_snapshot_name


::=
{
{ logical_backup_device_name |
@logical_backup_device_name_var }
| { DISK
| TAPE
| URL
} = { 'physical_backup_device_name' |
@physical_backup_device_name_var }
}


::=
{
FILE = { logical_file_name_in_backup | @logical_file_name_in_backup_var }
| FILEGROUP = { logical_filegroup_name | @logical_filegroup_name_var }
| READ_WRITE_FILEGROUPS
}


[ ,...n ]::=
--Restore Operation Options
MOVE 'logical_file_name_in_backup' TO 'operating_system_file_name'
[ ,...n ]
| REPLACE
| RESTART
| RESTRICTED_USER | CREDENTIAL


--Backup Set Options
| FILE = { backup_set_file_number | @backup_set_file_number }
| PASSWORD = { password | @password_variable }
| [ METADATA_ONLY | SNAPSHOT ] [ DBNAME = { database_name | @database_name_variable } ]


--Media Set Options
| MEDIANAME = { media_name | @media_name_variable }
| MEDIAPASSWORD = { mediapassword | @mediapassword_variable }
| BLOCKSIZE = { blocksize | @blocksize_variable }


--Data Transfer Options
| BUFFERCOUNT = { buffercount | @buffercount_variable }
| MAXTRANSFERSIZE = { maxtransfersize | @maxtransfersize_variable }


--Error Management Options
| { CHECKSUM | NO_CHECKSUM }
| { STOP_ON_ERROR | CONTINUE_AFTER_ERROR }


--Monitoring Options
| STATS [ = percentage ]


--Tape Options.
| { REWIND | NOREWIND }
| { UNLOAD | NOUNLOAD }


::=
| KEEP_REPLICATION


::=
| KEEP_CDC


::=
| FILESTREAM ( DIRECTORY_NAME = directory_name )


::=
| ENABLE_BROKER
| ERROR_BROKER_CONVERSATIONS
| NEW_BROKER


\
::=
| {
STOPAT = { 'datetime'| @datetime_var }
| STOPATMARK = 'lsn:lsn_number'
[ AFTER 'datetime']
| STOPBEFOREMARK = 'lsn:lsn_number'
[ AFTER 'datetime']
}


\
::=
| {
STOPAT = { 'datetime'| @datetime_var }
| STOPATMARK = { 'mark_name' | 'lsn:lsn_number' }
[ AFTER 'datetime']
| STOPBEFOREMARK = { 'mark_name' | 'lsn:lsn_number' }
[ AFTER 'datetime']
}