Method of querying a structure of compressed data
A method of querying a structure of compressed data comprising records stored as a forest of binary includes the step of generating an instruction set allowing a specified data value with a binary tree to be retrieved, given input of an address in memory that identifies the binary tree. Further querying functions which utilise the instruction set allow selection of records on the basis of one or more specified data values, or ranges of data values, statistical analysis of records and grouping of records on the basis of common data values within fields of records.
1. A method of querying a data structure which comprises a plurality of records, each record comprising a plurality of nodes structured as a binary tree, wherein the method comprises the steps of
(i) creating an instruction set for accessing a data value stored at a leaf node of a binary tree by:
(a) determining the leaf node's position address within a binary tree to which the node belongs;
(b) establishing the leaf node's lateral position index;
(c) entering an instruction in an instruction set, the instruction depending on the node's lateral position index; and
(ii) retrieving a data value stored at a leaf node of a binary tree using the instruction set and the binary tree's root node position address.
2. A method according to claim 1 further comprising the steps of:
(a) specifying a binary tree;
(b) specifying a instruction set;
(c) reading a data value stored within the binary tree at a node position address corresponding to the instruction set;
(d) adding the data value to a list in memory with a count of one if it has not previously been found within a binary tree or alternatively advancing a count variable in the list associated with that data value by one if the data value has previously been found within a binary tree; and
(e) repeating steps (a) to (d) for remaining binary trees in the data structure.
3. A method according to claim 2 further comprising the steps of:
(a) creating a table in memory for each data value in the list;
(b) reading a data value of a binary tree, the data value corresponding to the specified instruction set; and
(c) assigning the binary tree's root node address to a table depending on the data value corresponding to the specified instruction set; and
(d) repeating steps (b) and (c) for remaining binary trees in the data structure.
4. A method according to claim 3 further comprising the steps of:
(a) specifying an order for the data values in the list; and
(b) arranging the tables in an order corresponding to the order of the data values.
5. A method according to claim 1 further comprising the steps of:
(a) specifying a data value;
(b) determining the data value within a binary tree corresponding to the instruction set;
(c) establishing whether the data value determined in step (b) is equal to the specified data value, and if so adding the record corresponding to the binary tree to a list in memory;
(d) repeating steps (a) to (c) for remaining binary trees.
6. A method according to claim 1 wherein the steps of the method are implemented by arranging graphical elements in a graphical user interface.
7. A computer program for carrying out the method of claim 1 .
8. A computer program product storing a program for carrying out the method of claim 1 .
9. A computer system arranged to carry out the method of claim 1 .