No full table scan because you specify all the partition key columns in your WHERE clause.
On Thu, Dec 29, 2016 at 11:02 AM, Ashutosh Dhundhara < ashutoshdhundh...@yahoo.com> wrote: > Thanks DuyHai. > > One more thing, is it going to be a full table scan across all the nodes > in cluster? > > On Thu, Dec 29, 2016 at 3:30 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > >> In your case, ALLOW FILTERING will require Cassandra to scan linearly on >> disk and fetch all the partition data into memory so the performance >> depends on how "large" your partition is. For small partitions it should be >> fine. >> >> >> On Thu, Dec 29, 2016 at 10:00 AM, Ashutosh Dhundhara < >> ashutoshdhundh...@yahoo.com> wrote: >> >>> Hi All, >>> >>> I have a table like this: >>> >>> CREATE TABLE IF NOT EXISTS Posts ( >>> idObject int, >>> objectType text, >>> idParent int, >>> id int, >>> idResolution int, >>> PRIMARY KEY ((idObject, objectType, idParent), id) >>> ); >>> >>> Now have a look at the following query: >>> >>> SELECT * FROM POSTS WHERE idobject = 1 AND objectType = 'COURSE' AND >>> idParent = 0 AND idResolution = 1 ALLOW FILTERING >>> >>> Now the Partition Key is completely known, so if I use ALLOW FILTERING is >>> there going to be any performance issue because the filtering is going to >>> be done in a known single partition? >>> >>> >>> -- >>> Ashutosh Dhundhara >>> >> >> > > > -- > Ashutosh Dhundhara >
