Here’s a fun little experiment (I’m using Oracle 19.0 for this). First, let’s start off by creating a couple of tables. Cool! Now that we got our tables, let’s join them in a query and look a the plan. Here’s… 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