Mike Sherrill 'Cat Recall'

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location United States
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visits member for 3 years, 4 months
seen Jul 7 at 20:31

Database design and software development consultant. My clients included everything from Fortune 100 companies to non-profits and mom-and-pop companies. I've worked with SQL databases since 1985. I'm a database generalist; I'm comfortable with every modern SQL dbms. My home server runs a half-dozen different database management systems. I test most of my answers under more than one of them.

I've developed relational models for implementation in non-SQL environments, like Lotus Notes and plain C++ code.

I also develop software in C, VBA, Python, Ruby, and php. I build web applications using various frameworks and languages, including Ruby on Rails, Laravel, and Phalcon.


Apr
14
comment speeding up a query on MySql
Which columns are varchar(200)? The source columns or the target columns? GROUP BY on 10 million rows will probably take a while.
Apr
14
revised Database design: Dividing multiple identical tables, good or bad?
Extended examples.
Apr
14
revised Database design: Dividing multiple identical tables, good or bad?
Extended examples.
Apr
14
answered Database design: Dividing multiple identical tables, good or bad?
Apr
13
comment Functional Dependencies and Normal Forms
Are you being asked to determine the normal form for the relation R{ WX Y Z }, or the normal forms for { WX Y }, { WX Z }, and { Y Z }? (When you write "determine the form of:...", the of usually refers to whatever comes after.)
Apr
12
comment How database administrators can see my requests to SQL Server?
"Is there any other ways to see my activity?" Who cares? Are you trying to keep your activity a secret from the sysadmins?
Apr
11
comment Column or new table
Third normal form has to do with transitive dependencies. It has nothing to do with whether you store a school's name or its id number. (ID numbers have nothing to do with normalization.)
Apr
11
comment IP Address lookup star schema design
If I were in your shoes, I'd also want to test MySQL performance against PostgreSQL and its inet or cidr data type.
Apr
11
comment DB2 PureScale on Linux
I think asking IBM would give you a more actionable answer.
Apr
8
revised How to enforce full integer (no floating point)?
Cite 1992 SQL standard.
Apr
8
revised How to enforce full integer (no floating point)?
Added DDL.
Apr
8
answered How to enforce full integer (no floating point)?
Apr
8
comment Object-oriented programming CRUD design pattern
MySQL is the least standards-compliant, client/server dbms out there. When you're trying to do something that works well and easily on PostgreSQL, Oracle, and MySQL, you'll constantly get poked by MySQL's behavior.
Apr
7
answered Object-oriented programming CRUD design pattern
Apr
6
revised Defining constraints in `CREATE TABLE` statements
Note re version control.
Apr
4
comment Postgresql querying trends
Think about whether you might be better off doing this in a report writer.
Apr
2
comment Foreign keys - link using surrogate or natural key?
@JamesRyan: It's not a religious issue for me. I measured performance with both natural keys and surrogate keys at a company I used to work at. There's a tipping point at which surrogate keys begin to outperform natural keys. (Assuming no additional effort to keep natural key performance high, like partitioning, partial indexes, function-based indexes, extra tablespaces, using solid-state disks, etc.) By my estimates for that company, they'll reach that tipping point in about 2045. In the meantime, they get better performance with natural keys.
Apr
2
answered Foreign keys - link using surrogate or natural key?
Apr
2
answered BCNF when no keys are available
Apr
2
comment Foreign Keys with Composite Key
@Ciwan: Expanded my answer.