Is there any way to see how many rows are there using CLI mode? If I don't want to use CQL mode.
On Mon, Apr 22, 2013 at 12:13 AM, Nikolay Mihaylov <n...@nmmm.nu> wrote: > Hi > > it is very important to know that counting rows is very very > very expensive. > here is my 5 cents - > > in one of my early projects we made separate column family, with just > single row. > we inserted each row key from other CF on this row as column key. > > then once a day or who, we did get_count(). > > however because get_count() became way too slow, > we have split the keys on several rows - e.g. on 1024 rows. > it is still way too slow, but we do not need it to be realtime. > > in our "second" project we decided to use cassandra counters. > however in order to be distinct, we need to read before write. > this degrade insert performance, so we did special CF with hashesh and > other stuff. > insert performance is still slow. 2 sec or something for 500-600 counters > (note single insert is OK, but we need to do 500-600 per batch, and > 100-200 batches per second). > > finally we have researched about probabilistic counters and we decided to > use these. > we also decided to make the project in Python, and we did not do proper > tests yes. > > this is our final "take", it uses modified hyper log log, so we do not > need to read at all. > > https://github.com/nmmmnu/CubicHyperLogLog > > we tested the library very well, but not with real live data. > version for Redis is included too for easy testing. > > Nikolay. > > > > > > On Mon, Apr 22, 2013 at 2:19 AM, Utkarsh Sengar <utkarsh2...@gmail.com>wrote: > >> Difference b/w cqlsh and cli is documented by the datastax guys here >> nicely: http://www.datastax.com/support-forums/topic/cli-vs-cql >> >> Thanks, >> -Utkarsh >> >> >> On Sun, Apr 21, 2013 at 1:39 PM, Techy Teck <comptechge...@gmail.com>wrote: >> >>> Yeah it helps a lot. I always have this doubt with me. What is the >>> difference between CLI and CQL? >>> >>> >>> >>> On Sun, Apr 21, 2013 at 1:30 PM, Utkarsh Sengar >>> <utkarsh2...@gmail.com>wrote: >>> >>>> Using cqlsh you can do: >>>> >>>> SELECT COUNT(*) FROM columnfamily LIMIT 5000; >>>> >>>> Does that help? >>>> >>>> Read more: http://www.datastax.com/docs/1.0/references/cql/SELECT >>>> >>>> Thanks, >>>> -Utkarsh >>>> >>>> >>>> >>>> On Sun, Apr 21, 2013 at 1:04 PM, Techy Teck <comptechge...@gmail.com>wrote: >>>> >>>>> I have inserted 1000 rows in Cassandra database. Now I am trying to >>>>> find out how many rows have been inserted in Cassandra database using the >>>>> CLI mode. >>>>> >>>>> >>>>> In rdbms, I can do this sql- >>>>> >>>>> * SELECT count(*) from TABLE;* >>>>> >>>>> And this will give me total count for that table; >>>>> >>>>> How to do the same thing in Cassandra database? >>>>> >>>>> I am running Cassandra 1.2.3 >>>>> >>>> >>>> >>>> >>>> -- >>>> Thanks, >>>> -Utkarsh >>>> >>> >>> >> >> >> -- >> Thanks, >> -Utkarsh >> > >
