The modified column cannot be any one of the following: Some data type changes may cause a change in the data.For example, changing an nchar or nvarchar column to char or varchar may cause the conversion of extended characters.

The selects in red are blocked by the write operation in orange which is in turn blocked by the long-running select in green. There's a comprehensive list of things you might consider here on My SQL's site. My SQL barely imposes any artificial limits on the size a table can grow to but you're going to have to eventually make a call to split the table into shards or chunks. Most people shy away from sharding in My SQL because it's difficult.

This is what causes the table_locks_waited value to grow. While they're all worthy of consideration I can't help feeling some of them will only serve to delay the inevitable. My SQL are beginning to include partitioning themselves.

Here's an overview of what to look out for and how one might go about reducing the frequency at which they occur.

Before you embark on this please read How To Speed Up My SQL: An Introduction To Optimizing.

August 2009 The scourge of parallelism and scaling everywhere: locking.

Or in My SQL/My ISAM — and to be more precise — table locks.

For more information, see CAST and CONVERT (Transact-SQL).

Reducing the precision or scale of a column may cause data truncation.

That assumes of course the number of writes that occur on your database is few.

Or, and this is sometimes overlooked, that no one query takes more than an instant.

We're always impressed by his speedy problem solving, and ability to create complex, fail-safe solutions in unchartered domains.