Thanks Tyler & Stu, Tyler, as the alternatives for large no of subcolumns in a supercolumn, what do you suggest ? Like splitting up a 'supercolumnFamily' into several 'columnfamilies' ?? What else ?
On Sat, Jan 8, 2011 at 2:33 PM, Stu Hood <stuh...@gmail.com> wrote: > Raj: the super column indexing is a longstanding issue that we've been > considering recently, and would like to fix. > See https://issues.apache.org/jira/browse/CASSANDRA-674 > > On Fri, Jan 7, 2011 at 10:53 PM, Tyler Hobbs <ty...@riptano.com> wrote: >> >> Not that I'm aware of. There are several other decent alternatives to >> large amounts of subcolumns in a supercolumn, so I don't think it's a high >> priority. >> >> - Tyler >> >> On Fri, Jan 7, 2011 at 9:59 PM, Rajkumar Gupta <rajkumar....@gmail.com> >> wrote: >>> >>> Hey Tyler, >>> >>> Is this limitation of supercolumns going to be removed anytime sooner ? >>> >>> Raj >>> >>> On Fri, Jan 7, 2011 at 8:51 PM, Tyler Hobbs <ty...@riptano.com> wrote: >>> > An important bit to read about supercolumn limitations: >>> > http://www.riptano.com/docs/0.6/data_model/supercolumns#limitations >>> > >>> > Don't make supercolumns with a huge number of subcolumns (or a few >>> > really >>> > large subcolumns) unless you plan to always read all of them at once. >>> > >>> > - Tyler >>> > >>> > On Fri, Jan 7, 2011 at 1:27 AM, Arijit Mukherjee <ariji...@gmail.com> >>> > wrote: >>> >> >>> >> Thanx to both of you. I can now go ahead a bit more. >>> >> >>> >> Arijit >>> >> >>> >> On 7 January 2011 12:53, Narendra Sharma <narendra.sha...@gmail.com> >>> >> wrote: >>> >> > With raw thrift APIs: >>> >> > >>> >> > 1. Fetch column from supercolumn: >>> >> > >>> >> > ColumnPath cp = new ColumnPath("ColumnFamily"); >>> >> > cp.setSuper_column("SuperColumnName"); >>> >> > cp.setColumn("ColumnName"); >>> >> > ColumnOrSuperColumn resp = client.get(getByteBuffer("RowKey"), cp, >>> >> > ConsistencyLevel.ONE); >>> >> > Column c = resp.getColumn(); >>> >> > >>> >> > 2. Add a new supercolumn: >>> >> > >>> >> > SuperColumn superColumn = new SuperColumn(); >>> >> > superColumn.setName(getBytes("SuperColumnName")); >>> >> > cols = new ArrayList<Column>(); >>> >> > Column c = new Column(); >>> >> > c.setName(name); >>> >> > c.setValue(value); >>> >> > c.setTimestamp(timeStamp); >>> >> > cols.add(c); >>> >> > //repeat above 5 lines for as many cols you want in supercolumn >>> >> > superColumn.setColumns(cols); >>> >> > >>> >> > >>> >> > List<Mutation> mutations = new ArrayList<Mutation>(); >>> >> > ColumnOrSuperColumn csc = new ColumnOrSuperColumn(); >>> >> > csc.setSuper_column(superColumn); >>> >> > csc.setSuper_columnIsSet(true); >>> >> > Mutation m = new Mutation(); >>> >> > m.setColumn_or_supercolumn(csc); >>> >> > m.setColumn_or_supercolumnIsSet(true); >>> >> > mutations.add(m); >>> >> > >>> >> > >>> >> > Map<String, List<Mutation>> allMutations = new HashMap<String, >>> >> > List<Mutation>>(); >>> >> > allMutations.put("ColumnFamilyName", mutations); >>> >> > Map<ByteBuffer, Map<String, List<Mutation>>> mutationMap = new >>> >> > HashMap<ByteBuffer, Map<String, List<Mutation>>>(); >>> >> > mutationMap.put(getByteBuffer("RowKey"), mutations); >>> >> > client.batch_mutate(mutationMap, ConsistencyLevel.ONE); >>> >> > >>> >> > HTH! >>> >> > >>> >> > Thanks, >>> >> > Naren >>> >> > >>> >> > >>> >> > >>> >> > On Thu, Jan 6, 2011 at 10:42 PM, Arijit Mukherjee >>> >> > <ariji...@gmail.com> >>> >> > wrote: >>> >> >> >>> >> >> Thank you. And is it similar if I want to search a subcolumn within >>> >> >> a >>> >> >> given supercolumn? I mean I have the supercolumn key and the >>> >> >> subcolumn >>> >> >> key - can I fetch the particular subcolumn? >>> >> >> >>> >> >> Can you share a small piece of example code for both? >>> >> >> >>> >> >> I'm still new into this and trying to figure out the Thrift APIs. I >>> >> >> attempted to use Hector, but got myself into more confusion. >>> >> >> >>> >> >> Arijit >>> >> >> >>> >> >> On 7 January 2011 11:44, Roshan Dawrani <roshandawr...@gmail.com> >>> >> >> wrote: >>> >> >> > >>> >> >> > On Fri, Jan 7, 2011 at 11:39 AM, Arijit Mukherjee >>> >> >> > <ariji...@gmail.com> >>> >> >> > wrote: >>> >> >> >> >>> >> >> >> Hi >>> >> >> >> >>> >> >> >> I've a quick question about supercolumns. >>> >> >> >> EventRecord = { >>> >> >> >> eventKey2: { >>> >> >> >> e2-ts1: {set of columns}, >>> >> >> >> e2-ts2: {set of columns}, >>> >> >> >> ... >>> >> >> >> e2-tsn: {set of columns} >>> >> >> >> } >>> >> >> >> .... >>> >> >> >> } >>> >> >> >> >>> >> >> >> If I want to append another "e2-tsp: {set of columns}" to the >>> >> >> >> event >>> >> >> >> record keyed by eventKey2, do I need to retrieve the entire >>> >> >> >> eventKey2 >>> >> >> >> map, and then append this new row and re-insert eventKey2? >>> >> >> > >>> >> >> > No, you can simply insert a new super column with its sub-columns >>> >> >> > with >>> >> >> > the rowKey that you want, and it will join the other super >>> >> >> > columns of >>> >> >> > that >>> >> >> > row. >>> >> >> > >>> >> >> > A row have billions of super columns. Imagine fetching them all, >>> >> >> > just >>> >> >> > to >>> >> >> > add one more super column into it. >>> >> >> > >>> >> >> > >>> >> >> > >>> >> >> > >>> >> >> > >>> >> >> >>> >> >> >>> >> >> -- >>> >> >> "And when the night is cloudy, >>> >> >> There is still a light that shines on me, >>> >> >> Shine on until tomorrow, let it be." >>> >> > >>> >> > >>> >> >>> >> >>> >> >>> >> -- >>> >> "And when the night is cloudy, >>> >> There is still a light that shines on me, >>> >> Shine on until tomorrow, let it be." >>> > >>> > >> > >
