Category: Commerce Data Model

ChocolateFace 0

Reducing Contention: Changing Default Isolation Level for Websphere Commerce (WCS)

The Problem I often lean on analogies when I speak to non-technical people about technical topics. For example, I would explain database locking as “two kids fighting for the same candy bar”.  If you introduce isolation levels into the conversation, I would expand the analogy to include “one sibling holding on to a candy bar they care nothing about just...

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Improving Performance of DBCLEAN Deletes

While this post is specific to WebSphere Commerce, it covers concepts that may apply to tuning other delete statements as well. Using Functions in the Best Place 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)) >= ? Every time I see...

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Example of A Clustering Low-Cardinality Index Helping Query Performance

The request from the developers was something along the lines of “Help, Ember, this query needs to perform better”. Sometimes the query I’m working on is not one that shows up as a problem from the database administrator’s perspective, but one that is especially important in some part of application functioning. In this case, this query is related to the...

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Quick Hit Tips – CPUSPEED, RESTRICTIVE, and DB2_WORKLOAD

Today we are going to talk about some random DB2 features that can’t stand in a blog of their own, but are worth discussing nonetheless. These are tidbits I had discovered during “DB2’s Got Talent” presentations, IDUG conferences, or “Hey, look what I discovered” moments. CPUSPEED (Database Management Configuration) You blow past this setting every time you execute “db2 get...

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Redesigning Tablespaces in an Existing Database

Like many applications, WebSphere Commerce puts all tables in USERSPACE1 unless they need larger page sizes. This actually works just fine for smaller and midrange implementations, but we have about one build a year that requires something else – either because of standards that client DBAs adhere to or because they actually are busy enough for I/O and separate buffer...