Maximum number of columns in a table

Is there alot of overhead with having a big number of columns in a table ? Not unbounded, but say, would 2000 be a problem(I think that's the maximum I'll need) ? Thank You

Re: Maximum number of columns in a table

aving a lot of columns is the amount of meta data > C* needs to keep in memory for encoding/decoding each row. > > Now, if you have a table with 1000+ columns, the problem is probably your > data model... > > On Thu, Sep 15, 2016 at 2:59 PM, Dorian Hoxha <dorian.ho...@gmail.com> >

Re: Maximum number of columns in a table

.com <sfesc...@gmail.com> > wrote: > >> Another possible alternative is to use a single map column. >> >> >> On Thu, Sep 15, 2016 at 7:19 AM Dorian Hoxha <dorian.ho...@gmail.com> >> wrote: >> >>> Since I will only have 1 table with th

Re: Maximum number of columns in a table

st_visited_date": "2016-09-10 12:01:03", >> } >> >> INSERT INTO generic_with_maps(id, map_text, map_long, map_date) >> VALUES(xxx, {'name': 'John DOE'}, {'age': 32}, {'last_visited_date': >> '2016-09-10 >> 12:01:03'}); >> >> When you do a select,

Re: Efficient model for a sorting

ed-daybelgrade-2016/23 >> >> "If you partition your data by user_id then you query only 1 shard to >> get sorted by time visitors for a user" >> >> Exact, but in this case, you're using a 2nd index only for sorting right >> ? For SASI it's not even poss

Re: Efficient model for a sorting

> Secondary index (whatever the impl, SASI or Lucene) has a cost of > scatter-gather if your cluster scale out. With MV you're at least > guaranteed to hit a single node everytime > > On Tue, Oct 4, 2016 at 1:56 PM, Dorian Hoxha <dorian.ho...@gmail.com> > wrote: >

Re: Efficient model for a sorting

Can you use the lucene index https://github.com/Stratio/cassandra-lucene-index ? On Tue, Oct 4, 2016 at 1:27 PM, Benjamin Roth wrote: > Hi! > > I have a frequently used pattern which seems to be quite costly in CS. The > pattern is always the same: I have a unique key

Re: Rationale for using Hazelcast in front of Cassandra?

Maybe when you can have very hot keys that can give trouble to your 3(replication) cassandra nodes ? Example: why does facebook use memcache ? They certainly have things distributed on thousands of servers. On Thu, Oct 6, 2016 at 11:40 PM, KARR, DAVID wrote: > I've seen use

Re: Rationale for using Hazelcast in front of Cassandra?

t be to put a cache in front of a cache? > > > > *From:* Dorian Hoxha [mailto:dorian.ho...@gmail.com] > *Sent:* Thursday, October 06, 2016 2:52 PM > *To:* user@cassandra.apache.org > *Subject:* Re: Rationale for using Hazelcast in front of Cassandra? > > > > Maybe when

Re: Using keyspaces for virtual clusters

ak >>> this design) >> >> Or is it just a simple map dcx--->ip1,ip2,ip3 ? >> >> >> I just checked it. All the nodes would know about every keyspace and >> table, if using the same Cassandra cluster, (in my testing version C*3.7, >> this is stored under system_sc

Re: Maximum number of columns in a table

int25=5", while >> with normal columns I can." >> >> You have many objectives that contradict themselves in term of impl. >> >> Right now you're unlucky, SASI does not support indexing collections yet >> (it may come in future, when ? ¯\_(ツ)_/¯ )

Re: Having secondary indices limited to analytics dc

Only way I know is in elassandra . You spin nodes in dc1 as elassandra (having data + indexes) and in dc2 as cassandra (having only data). On Sun, Sep 18, 2016 at 5:43 PM, Bhuvan Rawal wrote: > Hi, > > Is it possible to have secondary

Using keyspaces for virtual clusters

Hi, I need to separate clients data into multiple clusters and because I don't like having multiple cql clients/connections on my app-code, I'm thinking of creating many keyspaces and storing them into many virtual datacenters (the servers will be in 1 logical datacenter, but separated by

Re: Way to write to dc1 but keep data only in dc2

(possibly trivial but > definitely not zero) amount of additional latency over: > > App ==high-latency==> DC2 > > The only exception would be if you had an expectation that latency between > DC1 and DC2 would be lower than latency between App and DC2, which I admit > is

Re: Way to write to dc1 but keep data only in dc2

@INDRANIL Please go find your own thread and don't hijack mine. On Mon, Oct 3, 2016 at 6:19 PM, INDRANIL BASU wrote: > Hello All, > > I am getting the below error repeatedly in the system log of C* 2.1.0 > > WARN [SharedPool-Worker-64] 2016-09-27 00:43:35,835 >

Re: Way to write to dc1 but keep data only in dc2

suggest an > alternative is to writing the data do a distributed commit log like kafka. > At that point you can decouple the write systems either through producer > consumer or through a tool like Kafka's mirror maker. > > > On Thu, Sep 29, 2016 at 5:24 PM, Dorian Hoxha <dorian.

Way to write to dc1 but keep data only in dc2

I have dc1 and dc2. I want to keep a keyspace only on dc2. But I only have my app on dc1. And I want to write to dc1 (lower latency) which will not keep data locally but just push it to dc2. While reading will only work for dc2. Since my app is mostly write, my app ~will be faster while not having

Re: [RELEASE] Apache Cassandra 3.9 released

So how does documentation work? Example: I'm interested in Change Data Capture. *I do appreciate the work done. On Thu, Sep 29, 2016 at 11:02 PM, Michael Shuler wrote: > The Cassandra team is pleased to announce the release of Apache > Cassandra version 3.9. > > Apache

Does increment/decrement by 0 generate any commits ?

I just have a bunch of counters in 1 row, and I want to selectively update them. And I want to keep prepared queries. But I don't want to keep 30 prepared queries (1 for each counter column, but keep only 1). So in most cases, I will increment 1 column by positive integer and the others by 0.

Re: Why does Cassandra need to have 2B column limit? why can't we have unlimited ?

Also, I'm not sure, but I don't think it's "cool" to write to multiple lists in the same message. (based on postgresql mailing lists rules). Example I'm not subscribed to those, and now the messages are separated. On Wed, Oct 12, 2016 at 10:37 AM, Dorian Hoxha <dorian.ho...@gma

Re: Why does Cassandra need to have 2B column limit? why can't we have unlimited ?

There are some issues working on larger partitions. Hbase doesn't do what you say! You have also to be carefull on hbase not to create large rows! But since they are globally-sorted, you can easily sort between them and create small rows. In my opinion, cassandra people are wrong, in that they