Block Dumps

Bitmap Indexes have a bad reputation with regard to being problematic and suffering from severe degradation following heavy DML operations, especially larger amounts of insert activity. Bitmap indexes have been known to grow substantially and require periodic rebuilds following such insert activity. While this was certainly the case in previous versions of Oracle, things have dramatically improved since version 10g. [...]

Although Bitmap Indexes are commonly created on one column, you can create multi-column, concatenated Bitmap indexes as well.   Many of the same issues and factors in deciding to create a single, multi-column index vs. several, single column indexes apply to Bitmap indexes as they do with B-Tree indexes, although there are a number of [...]

I thought before I jump into a topic that requires looking at a number of index block dumps, it might be worth briefly recapping how one goes about dumping index blocks in Oracle.   A block dump is simply a formatted representation of the contents of a particular Oracle database block.  Although I’ll be focusing [...]