The only thing that I found that seemed to match was a log buffer:

http://www.pythian.com/news/1581/log-buffer-139-a-carnival-of-the-vanities-for-dbas/

Which referenced Eric Emrick’s post here:
http://esemrick.blogspot.com/2009/03/low-cardinality-bitmap-index.html

Which seems to me to be an instance where Eric encountered an environment where someone held that myth.

If you think the article is poorly researched, though, you should probably comment on the original article, so that the author can get your feedback.

Log Buffer covers the DBA “blogosphere,” paying particular attention to posts that engender conversations, which Richard’s post did.

Each Log Buffer post is the work of its editor, and no one else.

“One of the great myths in Oracle is that bitmap indexes are only suitable and should only be used with columns that have so-called low cardinality (few distinct) values.”

This is not a great myth, or even a myth at all, according to Pythian’s own content!

Foote’s evidence does not support his conclusion.

You cannot take a single test case and extrapolate it to say that the bitmap guidelines are myths.
In fact Foote is creating new myths by suggesting that bitmaps are OK for OLTP and high-cardinality columns.

This link looks like a pathetic personal job, not valid research.

Please either remove this link or change Pythian’s pages to indicate that bitmaps are OK for OLTP and high cardinality columns!