3,382 reputation
1720
bio website karwin.com
location California
age 47
visits member for 3 years, 2 months
seen 12 hours ago

I'm Senior Knowledge Manager at Percona, a services company specializing in the MySQL database.

I've been a software engineer since 1987, and my specialty is as an SQL maven. I also have experience programming in Java, PHP, Perl, C, JavaScript, and I have many other coding skills.

I've written a book, SQL Antipatterns: Avoiding the Pitfalls of Database Programming from Pragmatic Bookshelf, based on the most common SQL problems I've answered on Stack Overflow and other forums, mailing lists, and newsgroups over the past 15 years.


Oct
16
revised 1 query using OR operator in where clause vs multiple query equal condition where clause in mysql
added 565 characters in body
Oct
16
answered 1 query using OR operator in where clause vs multiple query equal condition where clause in mysql
Oct
10
comment Percona MySQL 5.5 Unique key is duplicated
@PrakashK, here's a link: dev.mysql.com/doc/refman/5.6/en/binary-log.html
Sep
28
answered What is the cost of adding a foreign key in mysql?
Sep
26
revised Using an index for both asc and desc on a string column
added 498 characters in body
Sep
26
comment Using an index for both asc and desc on a string column
@ypercube, yeah, you're right, I think I created the collation naively by just reversing the order of all the bytes. It turns out that designing collations is more complex than can be done in a few minutes in a StackOverflow post! :-) Anyway, this answer at least serves as a demo of how to do it.
Sep
26
comment Using an index for both asc and desc on a string column
@ypercube, see example of CHAR above.
Sep
26
revised Using an index for both asc and desc on a string column
added 625 characters in body
Sep
25
comment Using an index for both asc and desc on a string column
It's a pretty odd case.
Sep
25
comment Using an index for both asc and desc on a string column
@Cratylus, I just copied the block of codes from the latin1_general_ci collation in the same file, and reversed the order.
Sep
25
comment Speed Up Index Creation in MySQL
I guess I assume everyone using MySQL is using a Linux server. Because for the most part, they are. Running a Windows server on a VM seems to me like fighting a boxing match with both hands tied behind your back.
Sep
25
comment Speed Up Index Creation in MySQL
See msdn.microsoft.com/library/dn197896.aspx, it confirms that you only get 300 IOPS per disk in Azure. That's really disappointing.
Sep
25
comment Speed Up Index Creation in MySQL
Okay then go with the tmpfs solution. Based on this and your other question, it sounds like your VM disks are really slow.
Sep
25
answered Speed Up Index Creation in MySQL
Sep
25
revised Using an index for both asc and desc on a string column
added 4265 characters in body
Sep
24
revised Using an index for both asc and desc on a string column
added 148 characters in body
Sep
24
answered Using an index for both asc and desc on a string column
Sep
24
answered WARNING Error checking mysqldump version Error retrieving version from mysqldump.exe: mysqldump: unknown option '--no-beep' (exit 2)
Sep
12
comment Amazon: How to change database name in Amazon RDS MySQL?
Aha, I tried it, and that doesn't work if you have triggers. I get an error: ERROR 1435 (HY000): Trigger in wrong schema
Sep
12
comment Amazon: How to change database name in Amazon RDS MySQL?
Why not just RENAME TABLE tablename TO db2.tablename; for each table? Then there shouldn't be any shipping of data back and forth.