A hub for sharing relational database knowledge and experimentation
While this post is specific to WebSphere Commerce, it covers concepts that may apply to tuning other delete statements as well.
The CLEANCONF table stores the delete statements that are used by DBCLEAN. Most of them use syntax like this for the date component:
(days(CURRENT TIMESTAMP) - days(prevlastsession)) = ?… Read the rest Continue reading »
We bandy about the term “online” reorg. But you’d be surprised how often there are issues with that. IBM officially calls it an “INPLACE” reorg. Read on to understand exactly when it is fully online and when it is not.
When we first got our hands on online reorgs, it seemed like the “INPLACE” keyword was all we needed, and we had availability during reorg – that any they required less disk space at one time.… Read the rest
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It happens. We joke that it doesn’t. Make sure not tell our Oracle or SQL Server counterparts but occasionally DB2 becomes … How do I put this eloquently? Hosed.
Snarled.
Non-functional.
Zombied (think the “Walking Dead” TV show).
Dorked.
Sometimes there is a memory leak, instance level crash, trap, or OS issue.… Read the rest
Continue reading »This post is specific to WebSphere Commerce. If you’re supporting WebSphere Commerce and you don’t know what dbclean is, get yourself a cup of coffee and start researching.
This post does not cover why to run dbclean or what parameters to use with dbclean – search my blog for more posts on that using the search box at the upper right or google.… Read the rest
Continue reading »In case anyone is wondering why I’m currently just barely managing one post a week, the first and most obvious reason is preparation for Black Friday/Cyber Monday. Retail clients really stress their databases on these days, and a bit of proactive work can go a long way.… Read the rest
Continue reading »Edited on 7/18/2012 to reflect lesson learned from a commenter.
First, a disclaimer. This process is only going to work for tables in AST tablespaces. It also will only work for tables that are not MDC, and do not have a clustering index.… Read the rest
Continue reading »One of my items to check before go-live is to see that data pruning is in place. Yes, before a website my company supports even goes live, I have at least made the attempt to start pruning the data that hasn’t been collected yet. … Read the rest
Continue reading »What do you do to prepare for the holidays? We’re starting to think about Black Friday for our retail clients in September or maybe even August. Each business has its Black Friday equivalent – the few days each year that account for 5%(or more) of your online revenue for the year – even if they aren’t anywhere near November.… Read the rest
Continue reading »By special request, I’m going to share some details on how to do a one-time offline clean up of guest users.
PLEASE NOTE: Following are suggestions only – it is critical to thoroughly test this before doing this in production. This is one of the most tested and still most failed changes I do.… Read the rest
Continue reading »This is part of a series focusing on the details of each item that needs to be pruned in a Commerce database.
Also known as abandoned shopping carts, these will just pile up if you don’t prune them.… Read the rest
Continue reading »This is a really complicated topic, largely because dbclean is such a varied tool, and because the data distribution in Commerce databases varries heavily based on how you use it. If you haven’t already, check out my blog entry on dbclean basics.… Read the rest
Continue reading »This is part of a series focusing on the details of each item that needs to be pruned in a Commerce database.
Guest Users are created by Commerce in the database. Technically they are only needed for when you allow a customer to add items to their cart before logging in or registering, or for a few other actions.… Read the rest
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