The vendor application is not likely to change a tad. There are 200+ times more updates and 50x inserts than analytical loads.
I can simply remove the indexes (in the RDBMS) and thus avoid the issue altogether, but I expect the analytical loads to suffer. In Cassandra to just be able to query (in CQL) on a column I have to have an index, the question is what tall the fragmentation coming from the frequent updates and inserts has on a CF? Do I also need to manually defrug? Or it is more or less manageable? Regards, Arthur ---- Original Message ---- From: Jack Krupansky <j...@basetechnology.com> To: user <user@cassandra.apache.org> Sent: Sun, Sep 28, 2014 11:41 am Subject: Re: Indexes Fragmentation It’s always a tradeoff between the level of sophistication of the platform and how much work you want to do in the application itself. But, yes, secondary indexing is always added overhead, and added complexity. And index tables are a viable approach as well. Again, trading off a simpler platform for added complexity in the application. Which way to go? As we say in data modeling, always start by looking at what queries and access patterns you expect to be using. So, how many different ways do you expect to query? Your original inquiry related to fragmentation due to heavy updates, but the background question remains how you intend to access that updated data? I mean, any perceived fragmentation may just be statistical noise compared to access efficiency overall. -- Jack Krupansky From: Arthur Zubarev Sent: Sunday, September 28, 2014 11:19 AM To: user@cassandra.apache.org Subject: Re: Indexes Fragmentation Thank you Jack, But I am afraid it may be an overhead. Added complexity. /Arthur ---- Original Message ---- From: Jack Krupansky <j...@basetechnology.com> To: user <user@cassandra.apache.org> Sent: Sun, Sep 28, 2014 11:03 am Subject: Re: Indexes Fragmentation Take a look at DataStax Enterprise as well, with its integrated Solr indexing of Cassandra data. -- Jack Krupansky From: Arthur Zubarev Sent: Sunday, September 28, 2014 10:55 AM To: user@cassandra.apache.org Subject: Indexes Fragmentation Hi all: A client on a RDBMS faces quick index fragmentations, statistics become inaccurate. Many within 4 hours (fast updates + writes, but mostly updates). I am looking into replacing the RDBMS with Cassandra. Will I face the same issue with indexes with Cassandra? Thank you! Regards, Arthur
