2,887 reputation
1618
bio website karwin.com
location California
age 46
visits member for 2 years, 11 months
seen 19 mins 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.


Jul
25
answered Is my MySQL instance irretrievably dead?
Jul
25
answered credentials file for running mysql related jobs via script?
Jul
25
comment Is my MySQL instance irretrievably dead?
Looks like you installed MySQL 5.1 over a 5.0 (or older) installation, without running mysql_upgrade to create new system tables and add columns to existing system tables.
Jul
23
awarded  Revival
Jul
15
comment Percona MySQL 5.5 Unique key is duplicated
To be fair, the market deserves some blame too, for creating the priority on performance over correctness.
Jul
15
revised Percona MySQL 5.5 Unique key is duplicated
added 176 characters in body
Jul
15
comment Converting to MyISAM, `foreign_key_checks = 0` Not Working
@ypercube, thanks, I have posted an answer to that question.
Jul
15
answered Percona MySQL 5.5 Unique key is duplicated
Jul
15
revised Converting to MyISAM, `foreign_key_checks = 0` Not Working
added 13 characters in body
Jul
14
answered Converting to MyISAM, `foreign_key_checks = 0` Not Working
Jul
7
awarded  Custodian
Jul
7
reviewed Approve suggested edit on InnoDB create table error: “Row size too large”
Jul
3
answered mysqld is not producing binary log
Jul
2
comment How to transfer 70GB MySQL with no downtime?
Another option for quick backups of MyISAM databases is LVM snapshots. A good tool to help is mylvmbackup. But your data directory needs to be on a volume capable of snapshots already.
Jun
30
awarded  Revival
Jun
20
comment Database Normalization - Can one field point to another?
As ypercube and mustaccio mentioned, a physical locator to the row is subject to change, as InnoDB moves rows around during updates. Besides, a foreign key typically references the primary key of the parent table, which is the clustered index of that table, and therefore pretty quick for lookups.
Jun
20
revised Converting MSSQL Stored Procedure to MySQL - Syntax Error
added 90 characters in body
Jun
20
comment Database Normalization - Can one field point to another?
And how large would such a pointer need to be, given that it would have to identify the tablespace, the page, the row, and column it references? Hint: almost certainly larger than the value you're likely to be referencing.
Jun
20
answered Converting MSSQL Stored Procedure to MySQL - Syntax Error
Jun
20
answered Database Normalization - Can one field point to another?