Why EAV is bad, mostly; and why it is used so often

Tom Kyte offers some astute observations regarding EAV data models in general.

Interesting to see the justification for entity-attribute-value data models from their use in the design of Oracle Application Express. I’d say I’d have to agree – the site I’m at currently is chocas with name/value pairs, which works fine when querying individual bits of data for the UI, but works miserably for reporting and batch jobs.