. Durity
From: Joe Obernberger
Sent: Tuesday, April 26, 2022 1:10 PM
To: user@cassandra.apache.org; 18624049226 <18624049...@163.com>
Subject: [EXTERNAL] Re: about the performance of select * from tbl
This would be a good use case for Spark + Cassandra.
-Joe
On 4/26/2022 8:48 AM, 18624
This would be a good use case for Spark + Cassandra.
-Joe
On 4/26/2022 8:48 AM, 18624049226 wrote:
We have a business scenario. We must execute the following statement:
select * from tbl;
This CQL has no WHERE condition.
What I want to ask is that if the data in this table is more than one
Yes, you CAN change the fetch size to adjust how many pages of results are
returned. But, if you have a million rows, you may still do hundreds or
thousands of queries, one after the next. Even if each is 1ms, it's going
to take a long time.
What Dor suggested is generating a number of SELECT stat
Thank you for your reply!
What I want to know is that the data volume of this table is not
massive. If the logic of CQL cannot be modified, just inside Cassandra,
are there any parameters that can affect the behavior of this query? For
example, the fetchSize parameter of other databases?
在 2
select * reads all of the data from the cluster, obviously it would be bad
if you'll
run a single query and expect it to return 'fast'. The best way is to
divide the data
set into chunks which will be selected by the range ownership per node, so
you'll
be able to query in parallel the entire cluste
We have a business scenario. We must execute the following statement:
select * from tbl;
This CQL has no WHERE condition.
What I want to ask is that if the data in this table is more than one
million or more, what methods or parameters can improve the performance
of this CQL?
