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MySQL一次主从数据不一致的问题解决过程 - 数据库(内核) - 清泛网 - 专注C/...

... pt-table-checksum校验数据一致性。 从库mysql操作 GRANT SELECT,PROCESS, SUPER, REPLICATION SLAVE ON *.* TO 'checksums'@'192.168.1.100' IDENTIFIED BY 'slavecheck'; flush privileges; ​ 主库mysql操作 GRANT SELECT, PROCESS, SUPER, REPLICATION SLAVE ON *.* TO 'checksums'@'19...
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What is “rvalue reference for *this”?

... If a class instance is not const, overload resolution will preferentially select the non-const version. If the instance is const, the user can only call the const version. And the this pointer is a const pointer, so the instance cannot be changed. What "r-value reference for this` does is allow yo...
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Insert Update trigger how to determine if insert or update

... track "before" and "after" data. So you can use something like IF EXISTS (SELECT * FROM DELETED) to detect an update. You only have rows in DELETED on update, but there are always rows in INSERTED. Look for "inserted" in CREATE TRIGGER. Edit, 23 Nov 2011 After comment, this answer is only for INSER...
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Favourite performance tuning tricks [closed]

...n-optimal query plan Break up the Join Can you break up the join? Pre-select foreign keys into a temporary table Do half the join and put results in a temporary table Are you using the right kind of temporary table? #temp tables may perform much better than @table variables with large volum...
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Why can't C compilers rearrange struct members to eliminate alignment padding? [duplicate]

...erent type than the one seen by the compiler, for example: struct S { char a; int b; char c; }; struct S_head { char a; }; struct S_ext { char a; int b; char c; int d; char e; }; struct S s; struct S_head *head = (struct S_head*)&s; fn1(head); struct S_ex...
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Errors: “INSERT EXEC statement cannot be nested.” and “Cannot use the ROLLBACK statement within an I

...our stored procedure data into it EXAMPLE: INSERT INTO #YOUR_TEMP_TABLE SELECT * FROM OPENROWSET ('SQLOLEDB','Server=(local);TRUSTED_CONNECTION=YES;','set fmtonly off EXEC [ServerName].dbo.[StoredProcedureName] 1,2,3') Note: You MUST use 'set fmtonly off', AND you CANNOT add dynamic sql to this...
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Enforcing the type of the indexed members of a Typescript object?

... a similar syntax to enforce that an object has a key for every entry in a union type: type DayOfTheWeek = "sunday" | "monday" | "tuesday" | "wednesday" | "thursday" | "friday" | "saturday"; type ChoresMap = { [day in DayOfTheWeek]: string }; const chores: ChoresMap = { // ERROR! Property 'saturd...
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Is it possible to declare two variables of different types in a for loop?

...ound (not that i'd actually use it unless forced to): for(struct { int a; char b; } s = { 0, 'a' } ; s.a < 5 ; ++s.a) { std::cout << s.a << " " << s.b << std::endl; } share | ...
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#define macro for debug printing in C?

... #include <stdarg.h> #include <stdio.h> void dbg_printf(const char *fmt, ...) { va_list args; va_start(args, fmt); vfprintf(stderr, fmt, args); va_end(args); } You can also use this technique in C99, of course, but the __VA_ARGS__ technique is neater because it uses re...
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How to use GROUP_CONCAT in a CONCAT in MySQL

... select id, group_concat(`Name` separator ',') as `ColumnName` from ( select id, concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name` from mytbl group by id, `Name` ) tbl group by id; ...