JPS6182251A - Storing system of relation type data base - Google Patents

Abstract

PURPOSE:To make it unnecessary to have information to be a NULL value, even if a column has the NULL value, and to improve the processing of a column unit, by providing an identifier for identifying a column, on column information of a relation type data base. CONSTITUTION:Cn is column information, a column ID for identifying the column information is stored in IDn, length information of data is stored in ln, and an actual data of Cr is stored in Dn. Also, in the row, the column is arranged in an ascending order of ID, therefore, for instance, with respect to the column ID, in case when a column of 3 is stored in the next of a column of 1, the column ID can signify that a column of 2 has a NULL value. Accordingly, by providing the column for identifying the column information, as for the column of the NULL value, the column information becomes unnecessary, and the processing of a column unit can be executed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a column information storage method suitable for improving the efficiency of processing in units of five columns, such as adding a new column, in a relational database.

[Background of the invention]

Generally, a tabular file that is expressed as a set of multiple rows of information and multiple columns of information is called a relational database. Conventionally, in such relational databases, rows were formed without column information having identifiers for identifying the columns, which caused the following problems.

(1) Even if the value of the column is N tJ LL, the column needs to have information that it is N tJ LL. That is, all column information must be stored in some form in the order established in the table.

(2) Processing becomes complicated when columns are added or deleted.

For a detailed explanation of the data storage method in a database system, please refer to Japanese Unexamined Patent Publication No. 55-F3184.
There is Publication No. 9, which creates a hierarchical structure in which data storage formats desired from a logical perspective and data storage formats desired from a physical condition are associated with virtual files and physical files, respectively. A means to analyze the above-mentioned problems in relational databases is essential.

[Purpose of the invention]

An object of the present invention is to provide a column information storage method that simplifies and speeds up column-by-column processing such as adding a new column, or processing when a column is a NULL value, in a relational database. It's about doing.

[Summary of the invention]

When processing for column + 1) (for example, adding a column) occurs, there is an identifier for identifying column l, and if so, the process can be executed based on that identifier. Furthermore, in the case of a NULL value column, the absence of the identifier can represent the N TJ LI value. The present invention provides for column information constituting row information of a relational database to include an identifier for identifying the column (hereinafter referred to as column TD) in addition to column actual data and data length information. This improves the efficiency of column-by-column processing.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

Data in the relational database is expressed in a table format as shown in FIG. Hereafter, this will be referred to as a table. R
n is row information (hereinafter referred to as row). C
This is n-column information (hereinafter referred to as a column),
It is an element that forms a row.

FIG. 1 shows a configuration diagram of rows in a database when the present invention is applied. Cn is one column information, and the fourth
This corresponds to the blank 13 information such as name, employee number, etc. shown in the figure. TDn,fl,...,D, are elements that constitute column information. TD, Haki example ke 2 by 1
It consists of an area of - and stores a column TD that stores column information. Column TDI.

The columns are defined in order of ], 2.3...n
and a sequence number. , an stores length information of data in column Cn. Dn stores the actual data of column Cn.

Within a row, columns are ordered in -1-ascending order of column TD. Therefore, by using the format 1- in Figure 1 = 3-, as shown in Figure 2, for example, if a column with column ID 3 is stored next to a column with column ID 1, , the column with column ID 2 is N U
It can be interpreted as the LL value. That is,
A NULL value column has no column information at all. In this way, if a column ID for identifying column information is provided, there is no need to store column information for columns with NULL values.

First, a method for detecting a pre-designated column in the row configuration shown in FIG. 1 will be explained. FIG. 3 shows a flowchart of the column detection process. In FIG. 3, An indicates the address of the n-th column. C is the column ID of the specified column. First, calculate An. This is done by finding the address of the first column in step 1 (initializing A), and finding the address of the n-th column from the address of the (n-1)th column in step 6. Column ID of the specified column and column ID of the relevant column
(The column ID of the column indicated by at1 nos A, l is I
D, ) are compared with each other, and if the result is the same, that column becomes the column to be detected (Step 4 - Step 8). ■Do
If is smaller, calculate the first-order An and compare it with the column ID of the first-order column (Step 5. Step 6)
. If TDn is larger, it means that the specified column TD does not exist or does not exist, and it turns out to be a NULL value (Step 3. Step 7). When An becomes equal to the final position (Aend) of the row, the column detection process in that row ends, and as a result, they are equal.
Since no column ID exists, the specified column turns out to be a NULL value (step 2).
．． Step 7).

Next, we will explain the case where a new column is added as table definition information. As shown in FIG. 5, suppose that a new column called address has been added to the table shown in FIG. In this case, all row information for the table stored in the database.

I need to add information about newly added columns. But 7. At this point, a new column has been added as standard information for the table, but no actual data has been added. That is, the data in the address column of the table in FIG. 5 is not entered. In this case, the value of the address column is the NUT-L value. In such a case, according to the column information storage method provided by the present invention, N U L
The L value does not have to have any information about the column. In other words, since column definition is provided, when a new column is added as table definition information, there is no need to add the column information as a NULL value to the row information in the database. It is.

Assuming that column TD is not provided, the address column value for all rows in the table in Figure 5 is N TJ
It is necessary to perform processing to add information that the value is LL.

As explained in Section 2 below, according to this embodiment, when a column is a NULL value column, it is no longer necessary to have information as a NUT-L value column, and column-by-column operations (column additions) processing) can be executed efficiently.

〔Effect of the invention〕

17= According to the present invention, by providing a column ID in column information in a relational database, a column can be identified by an identifier called column ■D, and N U L
It is possible to improve the processing efficiency and simplify the work regarding the processing related to the L value column, the additional processing for the 11th column, and the like.

4. Explanation of cylinder + 4t in the drawing Figure 1 is a general configuration diagram of a row stored in a database according to the method of the present invention, Figure 2 is a diagram of a concrete configuration of the row, and Figure 3 is a column diagram according to the method of the present invention. FIG. 4 is a flowchart of the detection process, FIG. 4 is a diagram showing an example of data in a relational database, and FIG. 5 is a diagram showing adding a new column to FIG. 4.

Rn...row, Cn...column, ■Dn...
Column, TD, Qn...Column data length, Dn
...Column data length A...Column address.

Figure 3

Claims (1)

[Claims] (1) In the storage method of relational databases expressed in table format, column information constituting each row information is stored in columns in addition to the actual data of the column and length information of the data A storage method for a relational database, characterized in that an identifier is provided and each column information is identified by the column identifier.