Summing Interval Data Types

Something I’ve occasionally thought would be really nice is if Oracle had a good way of summing interval data types, much the same way that you can SUM() number data types.  Occasionally I’ve designed processes that record start and stop… Read More

Handy trick to avoid ORA-54013: INSERT operation disallowed on virtual columns

In some regards, virtual columns are great: Virtual columns don’t take up physical disk space, which allow for skinnier tables. However, an annoyance with virtual columns is Oracle will give you an ORA-54013 error if you try to insert a… Read More

Reasons Oracle might pick a bad execution plan

Below is a list of possibilities as to why Oracle might pick a subpar execution plan: Your tables/indexes have missing or stale statistics (or stats are missing in table partitions/subpartitions or index partitions/subpartitions) Your data violates “uniformity” assumptions that Oracle… Read More