JPH03166647A - Function index control system - Google Patents

Abstract

PURPOSE:To retrieve a target record at a high speed by defining a function which sets a value derive secondarily by calculating a value or a constant of an arbitrary field in the record as a function index key value. CONSTITUTION:A function index defining means 1 defines a function for setting a value derived by calculating a value or a constant of an arbitrary field in a record as a function index key value. A record registering means 2 registers the record in a data base, and a function index key value generating means 3 generates a function index key value by calculating the function defined by the function index defining means 1 at the time of registering the record by the record registering means 2. A function index key record retrieving means 5 retrieves a function index key record having the function index key value at the time of retrieving the record, and a record retrieving means 6 retrieves a target record from a pointer value of the function index key record retrieved by the function index key record retrieving means 5. In such a way, the target record can be retrieved at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an index control method in a database system of an electronic computer, and more particularly to a function index control method in a database system.

[Conventional technology]

Conventionally, indexes in database systems have been used to quickly search for records with specific attributes. The specific attribute in this case is the value of any field within the record, and the value of the field is used as the index key value of the index key record. Therefore, searching for a record using the value of any field within the record can be performed at high speed.

However, these indexes cannot be used when searching for a record using a value that is calculated secondarily using field values or constants in the record; The necessary records are searched based on the results of manually calculating and determining the values of all records. FIG. 6 is a diagram showing an example of a conventional index control method.
In FIG. 6, a product record 61 shows product attributes, including a product code 62, a product manufacturing cost 63,
It consists of the unit price 64 at the time of product shipment and the number of shipments 65. Manufacturing cost 63. A manufacturing cost index 66, a unit price index 67, and a shipment quantity index 68 are generated, each using a unit price 64 and a shipment quantity 65 as index key records.

"Search for products whose manufacturing cost is 10,000 yen or more."
For such an arrangement, the manufacturing cost index 66 is used to search for the index key record 661 having the manufacturing cost 63 of 10,000 yen, and the searched index key record 66! Search for the record 611 pointed to by .

Next, manufacturing cost 63 larger than index key record 661
Search for the index key record 662 with , and search for the record 612 pointed to by the index key record 662. Repeat this step by step to search for the desired record. By the way, profit can be calculated using the following formula. Search for products that have a profit of 1 (unit price 1 manufacturing cost) x number of shipments rlo, 000 yen or more. ”, manufacturing cost index 6
6. The unit price index 67 and the shipment quantity index 68 cannot be used, so all records in the database are entered one by one, and the result of subtracting the manufacturing cost 63 from the unit price 64 is the shipment quantity 6.
Find the profit by multiplying by 5 and determine whether the profit exceeds 10,000 yen. This is done for all records included in the database to search for records that satisfy the conditions. [Problems to be Solved by the Invention] In the conventional index control method described above, when a record is searched using a value obtained secondary by calculation using the value or constant of an arbitrary field in a record, Since indexes cannot be used, the necessary record can only be retrieved by manually examining all the records in the database and determining the calculated value, so the processing time required for the search is extremely long. The disadvantage is that the desired record cannot be accessed quickly. In particular, when the population of databases to be searched is large, the CPU (central processing unit) time required for the search and the number of input/outputs of the database file become enormous, making such a search virtually unnecessary. It is possible. In view of the above-mentioned points, an object of the present invention is to calculate the value of an arbitrary field or constant in a record.
The purpose of this invention is to provide a functional index control method that allows a function to be defined that uses the next derived value as a functional index key value, thereby enabling high-speed retrieval of a desired record. [Means for Solving the Problems] The functional index control method of the present invention defines, in a database system, a function whose functional index key value is the value of an arbitrary field in a record or a value derived by calculating a constant. a function index definition means for registering a record in a database; and a function index for generating a function index key value by calculating a function defined by the function index definition means when a record is registered by the record registration means. A function index for registering a function index key record consisting of a key value generation means, a function index key value generated by the function index key value generation means, and a pointer value that is the address of the record registered by the record registration means. a key record registration means; a function index key record search means for searching for a function index key record having a function index key value when searching for a record; and a record search means for searching for a target record.

[Effect]

In the functional index control method of the present invention, the functional index definition means defines a function whose functional index key value is a value derived by calculating the value of an arbitrary field in a record or a constant, and the record registration means registers a record. The function index key value generation means generates the function index key value by calculating the function defined by the function index definition means when the record is registered by the record registration means, and the function index key record registration means generates the function index key value. A function index key record consisting of a function index value generated by the index key value generation means and a pointer value which is the address of the record registered by the record registration means is registered, and when the function index key record search means searches for a record, A functional index key record having a functional index key value is searched, and the record search means searches for a target record from the pointer value of the browsed index key record searched by the functional index key record search means. [Example] Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a functional index control method according to an embodiment of the present invention. The function index control system of this embodiment includes a function index definition means 1, a record registration means 2, a function index key value generation means 3, a function index key record registration means 4, a function index key record search means 5, It consists of 6 record search stages and 7 databases. The database 7 is structured to include records 8 and a function index 9. The function index 9 has a B-tree structure and has multiple layers (two layers shown) including an upper block 10 and a lowest block l1.
It has a hierarchical structure. The upper function index key record l2 of the upper block 10 points to the lowest block 1l,
The lowest function index key record 13 points to record 8. Next, the operation of the functional index control system of this embodiment configured as described above will be explained. The function index definition means 1 defines a function whose function index key value is a value derived by calculating the value of an arbitrary field in the record 8 or a constant. The record registration step 2 determines the address on the database 7 where the record 8 is to be stored and registers the record 8. The function index key value generation means 3 calculates the function defined by the function index definition means 1 when the record 8 is registered in the database 7 by the record registration means 2, and generates a function index key value. The function index key record registration means 4 is
A function index key record 13 consisting of a function index key value generated by the function index key value generation means 3 and a pointer value which is the address of the record 8 registered by the record registration means 2 is registered on the lowest block 11. ．． At this time, the function index key records 13 are stored on the lowest block 11 in the order of the function index key values. When the function index key record l3 is filled on the lowest block ll, the upper function index key record 12 whose function index key value is the maximum interval index key value of the function index key records 13 included on the lowest block 1l is created. is created on the upper block lO, the pointer value has the address of the lowest block 11, and it points to the lowest block l1. A search request for record 8 is made by specifying the function index key value of record 8 to be searched. In response to a search request for record 8, function index key record search means 5 searches function index key record 13 based on the function index key value requested. Search by reading the top 10 blocks,
Search the upper function index key record 12 that has the function index key value closest to and larger than or equal to the function index key value for which the search request was made in the upper block 10, and retrieve the pointer value of the upper function index key record l2. (address)
The lowest block 11 is searched, and the function index record 13 of the function index key value for which the search request was made is searched.

The record search means 6 searches for the record 8 based on the pointer {address) of the function index key record l3 searched by the function index key record search means 5.

Next, the operation of the functional index control method of this embodiment will be explained in Figs.
This will be explained in more detail with reference to Figure 5. FIG. 2 shows a product record 21 as an example of record 8.
This is a diagram showing. Product record 21 has product code 22
, the manufacturing cost 23 of the product, the unit price 24 at the time of product shipment, and the number of shipments 25. Product profit can be expressed by the following formula:

Profit (unit price - manufacturing cost) x number of shipments Figure 3 is a diagram showing a profit function 31 representing profit.The function index definition means 1 uses the above profit function 3l for calculating profit.
is defined in reverse Polish notation.

The function index key value generation means 3 calculates the profit function 31 defined by the function index definition means 1 when the record 8 is registered in the database 7 by the record registration means 2 to generate a function index key value. FIG. 4 illustrates the actual values of each field of the product record 21, and illustrates the actual values of the function index key values calculated by the function index key value generation means 3. Multiple product records 2 shown in Figure 4
The database 7 constructed by registering ``1'' by the record registration means 2 and the function index key record registration means 4 is shown in FIG. Search here for products that generate profits of rlO,000 yen or more. '', the function index key record search means 5 searches the profit index 52 in the search request for record 8 by setting the function index key value of the search request to 10,000. 10,00 on top bronc 53
The 30,000 higher order function index key records 532 having the function index key value closest to 0 are searched, and the lowest block 55 is searched based on the searched upper function index key records 532.
is read, and the function index key record 551 in the lowest block 55 is searched. The record search means 6 searches for the record 513 based on the pointer value (address) of the function index key record 551 searched by the function index key record search means 5. Next, the function index key record search means 5 checks whether there is a function index key record having a larger function index key value than the function index key record 551, and searches for the function index key record 552. The key record search means 6 searches for the record 512 based on the pointer value (address) of the function index key record 552. Similarly, record 516 is searched from the pointer value (address) of function index key record 553.

If the time required for a search is expressed as 1-0 times of blocks until record 8 is accessed, in the conventional case, the entire block including record 8 was needed I10 times. However, in the functional index control method of this embodiment, it is only necessary to trace the hierarchy of the functional index 9 rO times and to trace the block containing the target record 8 10 times.

For example, in a search where record 8 is searched from 1 million records 8, the prosoking function is 10.
In this case, 110 is issued 100,000 times in the conventional case, but in the function index control method of this embodiment, assuming that the function index 9 has three layers, the I −
Three 0s and one I-0 reading record 8 are sufficient.

In this way, in the functional index control method of this embodiment, the target record 8 can be searched at high speed using a function that is derived secondarily by calculating the value or constant of any field in the record 8. ．． [Effects of the Invention] As explained above, the present invention defines a function whose function index key value is a value derived secondarily by calculating the value of any field in a record or a constant. This has the advantage that a functional index can be automatically created, and a desired record can be searched at high speed using this functional index.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of a functional index control method according to an embodiment of the present invention, FIG. 2 is a diagram showing the contents of a product record, which is an example of the record in FIG. 1, and FIG. Figure 4 is a diagram illustrating the product record shown in Figure 2 and the realized value of the profit function shown in Figure 3. Figure 5 is a diagram showing the profit function defined based on the product record in Figure 2. FIG. 6 is a diagram showing an example of the operation of the product data database to which the functional index control method 2 of the embodiment is applied, and FIG. 6 is a diagram showing an example of the operation of the conventional index control method. In the figure, 1...Function index definition means, 2...Record registration means, 3...Function index key value generation means, 4...Function index key record registration means, 5...Function index key record Search means, 6...Record search means, 7...Database, 8...Record, 9...Function index, 10...Upper block, 1l...Lowest block, l2...Upper function index key Record, 13...Function index key record, 2l...Product record, 22...Product code, 23...Manufacturing cost, 24...Unit price, 25...Number of shipments, 31...Profit function, 52...Function index , 53... Upper block, 54.55 Lower bronch, 511-516 Record, 531.532 Upper function index key record, 541-
543,551-553...Function index key record.

Claims (1)

[Claims] In a database system, a function index definition means for defining a function whose function index key value is a value derived by calculating a value of an arbitrary field in a record or a constant; a record registration means for generating a function index key value by calculating a function defined by the function index definition means when a record is registered by the record registration means; function index key record registration means for registering a function index key record consisting of a function index key value generated by the means and a pointer value that is an address of the record registered by the record registration means; It has a function index key record search means for searching for a function index key record having a value, and a record search means for searching for a target record from the pointer value of the function index key record searched by the function index key record search means. A functional index control method featuring: