If you read my blog post about 2nd index deep dive, you'll get all the
answers
Le 21 oct. 2016 10:20, "Kant Kodali" a écrit :
> Why Secondary index cannot be broken down into token ranges like primary
> index at least for exact matches? That way dont need to scan the whole
>
Why Secondary index cannot be broken down into token ranges like primary
index at least for exact matches? That way dont need to scan the whole
cluster atleast for exact matches. I understand if it is a substring search
then there will 2^n substrings which equates to 2^n hashes/tokens which can
be
If each indexed value has very few matching rows, then querying using SASI
(or any impl of secondary index) may scan the whole cluster.
This is because the index are "distributed" e.g. the indexed values stay on
the same nodes as the base data. And even SASI with its own data-structure
will not
Well I went with the definition from wikipedia and that definition rules
out #1 so it is #2 and it is just one matching row in my case.
On Sat, Oct 15, 2016 at 2:40 AM, DuyHai Doan wrote:
> Define precisely what you mean by "high cardinality columns". Do you mean:
>
> 1)
Define precisely what you mean by "high cardinality columns". Do you mean:
1) a single indexed value is present in a lot of rows
2) a single indexed value has only a few (if not just one) matching row
On Sat, Oct 15, 2016 at 8:37 AM, Kant Kodali wrote:
> I understand
I understand Secondary Indexes in general are inefficient on high
cardinality columns but since SASI is built from scratch I wonder if the
same argument applies there? If not, Why? Because I believe primary keys in
Cassandra are indeed indexed and since Primary key is supposed to be the
column