Hi
If you declare a FK constraint, MonetDB will create a join index immediately. For primary keys, a hash would mostly be chosen, which is fast to exploit in a join as well.
regards, Martin
On 10/22/13 7:07 PM, Hilario Fernandes wrote:
Hi,
I've been trying to understand if there is any performance benefit in using primary and foreign key constraints when performing join queries.
I've tested joining a table with 1 million rows with one with 60k. Tryed the same queries with and without constraints and couldn't see a significant change in execution time.
The tables are not that big but they are a sample of what we'll be working with in average.
Should i be seeing any difference? Hows do PK and FK constraints affect query performance in Monetdb? Will it only be noticeable with larger datasets?
Thank you
Hilario Fernandes
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