Hi,
Is there a any way to enhance the performance of queries using the LIMIT option? It seems like if I am querying large tables, even adding a LIMIT 1 still takes a long time...
Thanks guys!
Help with LIMIT performance?
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Re: Help with LIMIT performance?
What does your query look like?
Also take a look at Optimizing LIMIT Queries with ROW_NUMBER Predicates.
Also take a look at Optimizing LIMIT Queries with ROW_NUMBER Predicates.
Checkout vertica.tips for more Vertica resources.
Re: Help with LIMIT performance?
It’s going to depend greatly on what sort of query you are executing. Each node will limit the data that it sends back to the initiator to a single row as quickly as it can. But if the query needs to do lots of work before it can apply the LIMIT 1 then you need to wait. For example a large GROUP BY HASH that is executing prior to the LIMIT 1 will need to finish executing before the LIMIT 1 can be applied.
How long is the “long time” in your case?
—Sharon
How long is the “long time” in your case?
—Sharon
Sharon Cutter
Vertica Consultant, Zazz Technologies LLC
Vertica Consultant, Zazz Technologies LLC