Query Performance Analysis

Some of the more complicated work a DBA does is often analyzing a query. Whether it is proactive or in response to a performance problem, there are so many factors that go into query performance. Even when looking at a query that has a performance problem, there is only occasionally a single, obvious cause for all of the problems.… Read the rest

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Funny SQL I Have Seen Lately

I’ve run across a few strange SQL statements lately, and while the mistakes they make are not the most impactful, I thought I’d share how I think they could be better written.

Unnecessary use of a Common Table Expression

This query isn’t really wrong, it just doesn’t make much sense.… Read the rest

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Using DB2’s ADMIN_MOVE_TABLE to Move Tables from One Tablespace to Another

What is ADMIN_MOVE_TABLE

ADMIN_MOVE_TABLE is an administrative stored procedure introduced in DB2 9.7. The intent is to provide a tool that can be used to perform an online move of a table, while transactions are still occurring against the table. Moves can be used to change what tablespace a table is in, convert a table to MDC, change the table name, perform several changes that would normally require reorgs, reduce the size of a column, and perform other changes.… Read the rest

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