数据库 information schema 和 mysql可以删除么？

当然是不可以删除的。

1.information schema 是mysql系统用的所有字典信息，包括数据库系统有什么库，有什么表，有什么字典，有什么存储过程等所有对象信息和进程访问、状态信息。

一旦删除该数据库系统将无法使用。

2.mysql数据库是保存系统有关的权限，对象和状态信息。同样是不能删除的。

并且这两个数据库都很小，不占用空间，你为什么要删除呢。？

--SQL清除所有数据库日志脚本

declare @CurrentDataBaseName nvarchar(100)

declare @CurrentDataBaseID nvarchar(100)

declare @CurrentLogName nvarchar(100)

declare @CurrentClearString nvarchar(4000)

declare @CurrentLogFileName nvarchar(255)

declare @CurrentClearLogString nvarchar(2000)

--查询所有数据库名称

--select * from master..sysdatabases where dbid>=7

declare tb cursor local for select name,dbid from master..sysdatabases where dbid>=7

open tb

fetch next from tb into @CurrentDataBaseName,@CurrentDataBaseID

while @@fetch_status=0

begin

--查询指定数据库对应的所有日志文件

--select * from sys.database_files

--使用游标查询数据库对应的日志文件

set @CurrentLogFileName=''

set @CurrentClearLogString=''

--select * from sysaltfiles where dbid=7 and status>2

declare tf cursor local for select name from sysaltfiles where dbid=@CurrentDataBaseID and status>2 and groupid<>1

open tf

fetch next from tf into @CurrentLogFileName

while @@fetch_status=0

begin

if @CurrentClearLogString<>''

begin

set @CurrentClearLogString+='

DBCC SHRINKFILE (['+@CurrentLogFileName+'] , 11, TRUNCATEONLY)'

--print @CurrentClearLogString

end

else

begin

set @CurrentClearLogString='

DBCC SHRINKFILE (['+@CurrentLogFileName+'] , 11, TRUNCATEONLY)'

end

--print '当前清除日志文件语句'+@CurrentClearLogString

fetch next from tf into @CurrentLogFileName

end

close tf

deallocate tf

--print @CurrentClearLogString

set @CurrentClearString='

USE [master]

ALTER DATABASE ['+@CurrentDataBaseName+'] SET RECOVERY SIMPLE WITH NO_WAIT

ALTER DATABASE ['+@CurrentDataBaseName+'] SET RECOVERY SIMPLE

USE ['+@CurrentDataBaseName+']'+@CurrentClearLogString+'

USE [master]

ALTER DATABASE ['+@CurrentDataBaseName+'] SET RECOVERY FULL WITH NO_WAIT

ALTER DATABASE ['+@CurrentDataBaseName+'] SET RECOVERY FULL'

print @CurrentClearString

exec sp_executesql @CurrentClearString

print '清除数据库'+@CurrentDataBaseName +'日志完成, *** 作语句'

fetch next from tb into @CurrentDataBaseName,@CurrentDataBaseID

end

close tb

deallocate tb

print '清除所有数据库日志完成'

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