Performance Implications Loading Data with Bitmap Indexes
The biggest payoff for using bitmap indexes is that they help the speed of queries. The bitmap indexes can be created very quickly in comparison to B-tree indexes, and they consume much less space than a B-tree index. The trade-off for gains with these distinct advantages is the impact bitmap indexes have on DML operations on tables containing bitmap indexes. Bitmap indexes can be created quickly and can be scanned quickly to help query performance, but they are not designed to support DML operations very well.
What the following example demonstrates is that it is actually much faster to simply drop and recreate bitmap indexes before and after a load operation. In the following example, ...
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