MySQL Bugs: #69163: Mysqldump: option for limit and for reverse sorting

Bug #69163	Mysqldump: option for limit and for reverse sorting
Submitted:	7 May 2013 10:39	Modified:	7 May 2013 10:47
Reporter:	Marco Gergele	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: mysqldump Command-line Client	Severity:	S4 (Feature request)
Version:	5.5	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	Contribution

Description:
mysqldump can sort by primary key, but only ascending.

mysqldump can not limit the number of rows.

I have added two options: 

--order-by-primary-desc 
                      Sorts descending each table's rows by primary key, or
                      first unique key, if such a key exists.  Useful when
                      dumping a MyISAM table to be loaded into an InnoDB table,
                      but will make the dump itself take considerably longer.

--limit[=name]      (numeric!) Number of rows of each table to dump, 0=all
                     rows

I do need the number for "limit" as a string, so I try to avoid converting it into numbers and back into string.

How to repeat:
mysqldump --order-by-primary sorts ascending, there is no option for descending sort.

Suggested fix:
Patch posted at internals.mysql.com 2013-05-05

Patch for mysqldump.c

Attachment: mydump.diff.txt (text/plain), 4.90 KiB.

Thank you for the reasonable feature request.

Can anyone implement this?

It is really good request. Sometimes it is needed to dump database with tables without primary keys. Dump last N records from tables without PK is a good idea.