CasBase is an open source project that aims to add secondary indexing capabilities to Apache Cassandra similar to relational databases by implementing techniques like composite columns, hashed and ordered buckets for indexing, and custom data types to support null values. The presentation discusses the motivation for CasBase, how it implements various indexing approaches like unique and non-unique indexes, and deals with challenges of Cassandra's data model like null values. CasBase is available on GitHub and provides a concrete way to build indexes in Cassandra through its API.

1. CasBase Edward Capriolo

3. Elevator pitch... tabular get Cassandr'ified

4. Pet project (not production ready...yet)

5. Semi quixotic quest to make c* work like RDBMS

7. Fixed columns

8. Normalized

10. Ragged Columns

11. De-normalized *

12. Schema less *

13. Q. Because Cassandra is NoSQL store what is the first step in using it?

14. A. Strap relational database features and frameworks on top until it works like a relational database!* * Just Kidding / No Seriously

15. Obligatory Cassandra slides

16. Obligatory Data Model Slide

17. Obligatory physical data model

18. Obligatory Distribution Model

20. Row Key locates server(s) with data

21. SSTable Sorted by row key

23. CasBase motivation

25. new Table(“mystuff”).addColumn(“a”,string).addIndex(“aidx”,[”a”]).create();

26. Insert data

27. client.insert(“mystuff”, “ed”, { a=5,b=6 } );

28. Ask questions

29. List<Col> a=client.find(“mystuff”, “a”, “5”);

31. Unique index enforcement

32. Indexes of column names i.e. rows with column.name=username (ldap presence) *

33. Index on value i.e. username ='bob' age>4 age<8 *

34. * well not exactly. 0.7 added secondary indexes, but still reasons to make your own

36. Inserts / overcerts

37. Specific column must exist for row on insert

38. Unique indexes

39. On delete or updates repair index now or defer until read

40. “ Auto-magically delicious” index building in CasBase

42. Indexes in Cassandra (ed enuff)

44. Escaping?

45. Empties?

47. Schema validators

48. Reasonable slicing

49. cli support

51. But if you want it, you want it.

52. Not atomic in CasBase, could be with zookeeper/cages (maybe next month)

54. Cardinality could be a challenge in some cases (not much different from relational)

56. set user['bsmith']['dog']='rover'

57. set userdogs['rover']['bsmith']=''

58. Hashed

59. Hashed

61. dogs => 'rover' AND dogs <= 'sinbad'

63. Row not sharded (c* replication unit is row)

65. Do not even mention order preserving partitioner (Mdennis will find you)

66. If you only remember one thing from this talk

68. Create a fixed number of shards/buckets

69. set user['bsmith']['dog']='rover'

70. set userdogs['hash(rover) % buckets'][composite(rover,bsmith)]=''

71. Value mod buckets finds shard key

72. Column composite(value,src_row)

75. 1 look up for equality/exist search

76. Each bucket is ordered

78. Bucket2: name > roger and name < sinbad ...

79. AnyType, because CasBase needs null

81. C* does not allow null or '' rowkey, column name or value

82. Types like LongType don't have a null

83. Argue that a non existing column is null

84. But you can not build a reverse index where 'value is null'

86. Push meta data down to column

87. byte[0] specifies type 1=int, 2=string, 3=varint, 4=binary, 5=gson serialized obj

88. byte[1]-byte[n] is actual data.

89. Sorting - Types sort first, 2 nd sort is compareTo

91. Any a = new Any(String.class, “what up”);

92. AnyType.instance.composeAny(a) -> Ugly ByteBuffer for Cassandra

93. AnyType.instance.decomposeAny(BB) -> ByteBuffer back to Any

95. Pet project but great concrete implementation of index building, composite columns

96. Now'ish: Efficient map reduce

97. Future: locking w zookeeper/cages

98. Far Future: Query engine (right now API only)

100. http://github.com/edwardcapriolo/Cassandra-AnyType

101. ?????????? ?Questions? ??????????