I am using Derby as an in-memory DB.
While executing a complex query (which contains a union and several left-joins),
we discovered that this query with a left join would take about 3.5 mins
to execute and fetch the data, whereas the same query with the left join
replaced with the inner join would take just 30 seconds.
What tools or API is available at our
disposal to tune the in-memory Derby, to see its execution plan, to try
to figure out why it is taking such an extraordinary time to fetch about
I also noticed that by running the same
query over and over, the time to execute and fetch seems to be slowly creeping
up as well - it started with 2.5 mins, then grew to 3 mins and now it's
almost 4 mins.
Any help would be greatly appreciated!
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