JPH0664587B2 - Search condition determination method in search processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a record group having a content that matches a specified search condition expression from among a huge record group stored in a secondary storage device or the like. In particular, the present invention relates to a method of determining a composite conditional expression among search conditional expressions in a search processing device that selectively outputs only.

[Conventional technology]

Configuration example of a search processing device (data content search processing device) that selectively outputs only a record group having contents that match a specified search condition expression from among a huge record group stored in a secondary storage device or the like Is shown in FIG. In FIG. 3, 1 is a secondary storage device that stores a record group, 2 is a data content search processing device, and 9 is a main body device. The data content search processing device 2 determines whether or not a unitary conditional expression given to each field of the read record group is established or not, and a secondary storage control unit 3 that controls reading and writing of data from and to the secondary storage device 1. The unit conditional expression judging unit 4 that performs the above, and the establishment of the compound conditional expression given using the judgment result of the unit conditional expression,
A composite conditional expression determination unit 5 that determines whether the condition is not satisfied, and a record buffer unit 6 that temporarily stores the read record and that selects and temporarily stores only the record group in which the composite conditional expression is satisfied
And an I / O interface control section 7 for transferring the record group selected by the record buffer section 6 to the main body apparatus 9.
And a common control unit 8 that controls the entire processing and performs a search preparation process.

FIG. 4 shows an example of the structure of a record targeted by the data content search processing device 2. In this case, the records are F1, F2 and
An example is shown in which the field is composed of five fields F3, F4 and F5. Table 1 shows an example of a search condition expression for this search processing target record.

The unit condition expression 1 (UC1) and the unit condition expression 2 (UC
2) and the unit conditional expression 3 (UC3) specify that the field F1 is equal to the constant C ₁ , the field F2 is larger than the field F3, and the field F4 is equal to or less than the constant C ₂ , respectively. Compound conditional expression (G)
Specifies that the search condition expression is satisfied when both UC1 and UC2 are satisfied, or when UC1 is not satisfied and UC3 is satisfied. Unit conditional expressions UC1, UC
2, UC3 are sequentially judged by the unit conditional expression judging unit 4, and the composite conditional expression G is used as the composite conditional expression judging unit 5 by using the judgment result.
Is determined by.

FIG. 5 shows a unit conditional expression judgment result signal from the unit conditional expression judging unit 4 to the composite conditional expression judging unit 5 in the conventional method. When the target field of the unit conditional expression has a specific value, the unit conditional expression judgment unit 4 judges whether the condition is satisfied or not, depending on the conditional expression and the field value. On the other hand, when the field does not have a specific value (in this case, the field value is said to be a “blank value”), the unit conditional expression is “established” or “not satisfied”.
Cannot be determined, and is “undefined”. For this reason, conventionally, as shown in FIG. 5, a unit condition expression determination result signal requires three values of “established” (T), “not established” (F), and “undefined” (M).

In the composite conditional expression determination unit 5, the three values (T, F,
For M), AND, according to the given compound conditional expression,
A logical conditional operation of OR and NOT is executed, and when the final result is “established” (T), the composite conditional expression is established. Also,
If the determination result of the complex conditional expression is "undefined", it is assumed that the record does not match the search condition.

Tables 2, 3, and 4 define AND, OR, and NOT operations for the three values of T, F, and M, respectively. All compound conditional expressions can be determined by repeating the operations of these tables.

[Problems to be Solved by the Invention] As described above, in the conventional method, the “conditional” (T) and “failure” of each unit conditional expression judged by the unit conditional expression judging unit are satisfied.
For the three values of (F) and "indefinite" (M), the composite conditional expression judgment unit AND, O according to the given composite conditional expression.
Since it is necessary to execute the R and NOT operations, the complex conditional expression determination unit has a complicated configuration and has a drawback that the circuit scale becomes 3 to 4 times larger than that in the case of a binary value.

An object of the present invention is to provide a search condition determination method capable of determining a compound conditional expression by executing a simple binary operation without executing the T, F, and M ternary operation.

[Means and Actions for Solving Problems]

According to the present invention, as a search preparation operation, for a unit conditional expression to which NOT is added in the compound conditional expressions given as the search condition, the determination result of the unit conditional expression (“established”,
By converting to a unit conditional expression such that “not satisfied” is reversed, NOT is deleted from the compound conditional expression while preserving the equivalence with the original search conditional expression. After the search process starts,
In the determination of the unit conditional expression, when the corresponding field value is a blank value, the unit conditional expression is “not satisfied”. That is, the judgment result of the unit conditional expression is “established” and “not satisfied”.
The "indefinite" state is eliminated as the value only, and ordinary binary AND and OR operations are applied to the determination of the complex conditional expression.

In the judgment of the unit conditional expression, the NOT is included in the composite conditional expression, and the unit conditional expression is made "not satisfied" with respect to the blank value, and the binary conditional AND, O is added to the judgment logic of the composite conditional expression.
If the R and NOT operations are applied, the final determination result may be inconsistent. Therefore, as the preparatory operation for the above search, while maintaining the equivalence with the given search condition expression,
It is converted into a format that does not include NOT in the compound conditional expression. When the target field of the unit conditional expression is other than a blank value, it is determined in accordance with the value whether it is “established” or “not established” as in the conventional case.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

Also in the present invention, the overall configuration of the data content search processing device is as shown in FIG. FIG. 1 shows a unit conditional expression judgment result signal from the unit conditional expression judging unit 4 to the composite conditional expression judging unit 5 in the method of the present invention.

In the present invention, after the unit condition expression and the search condition of the compound condition expression are given, as a preparatory operation for the search, the unit condition expression to which NOT is added in the compound condition expression is By converting to the unit condition expression that the judgment result of “(established (T) and“ not established ”(F)) is reversed, the equivalence with the original search condition expression is preserved and the composite condition is maintained. Remove NOT from the expression.

Regarding the search conditions shown in Table 1, the converted search conditions are shown in Table 5.

Immediately, since NOT is given to UC1 in the compound conditional expression G of Table 1, it is converted into a unit conditional expression in which the determination result is reversed for UC1, and this is designated as UC4. However, since there is UC1 to which NOT is not added in the compound conditional expression G, UC1 itself is also left. In this way, it is equivalent to the compound conditional expression G and NOT is used. A complex conditional expression that does not exist is obtained like G '.

After the search processing is started, the unit conditional expression determination unit 4 determines that the unit conditional expression is “not satisfied” when the target field of the unit conditional expression is a blank value. Therefore, the unit conditional expression judgment result signal from the unit conditional expression judging unit 4 to the composite conditional expression judging unit 5 may express two values of “established” (T) and “not satisfied” (F). FIG. 1 shows the determination result signal using a 1-bit signal line 10 in which T is represented by "1" and F is represented by "0". The composite conditional expression determination unit 5 executes the composite conditional expression determination that does not include NOT like G ′ in Table 5 with respect to the binary value “1” and “0” of the determination result of each unit conditional expression. To do.

FIG. 2 shows an example of the configuration of the composite conditional expression judging unit 5, and 10 is a signal for sequentially inputting the judgment result (“1” or “0”) of each unit conditional expression in the unit conditional expression judging unit 4. Line, 11
Is a result latch that holds the judgment result of each unit conditional expression input through the signal line 10. In the present embodiment, X ₁ , X ₂ , X ₃ ,
It consists of 4 bits of X ₄ , 12 is a 4-bit result latch 1
It is a 16-word × 1-bit decision memory having an address obtained by combining 1s.

In the example of Table 5, the maximum number of unit conditional expressions is 4, and 16 combinations of all the unit conditional expressions are satisfied or not satisfied.
Depending on the given complex conditional expression, some of the above 16 combinations satisfy the complex conditional expression. In the search preparation operation, "1" is set to the word of the memory 12 corresponding to the set of the unit conditional expressions that satisfy the complex conditional expression,
Set "0" in other words. After the search process is started, the determination result of each unit conditional expression is set to "1" or "0" in the result latch 11 according to the field value of each record. When all the latches are set, the corresponding word of the judgment memory 12 is read using the value as an address. If the word is "1", the compound conditional expression is "established", and conversely, if it is "0", it is "not satisfied". It should be noted that the result latches that do not need to be allocated due to the small number of unit conditional expressions are fixed at "0".

In the example of Table 5, shows the set value of the decision memory 12 when the unit condition UC1~UC4 assigned X ₁ to X ₄ et results of each latch 11 in Table 6.

Here, as shown in Table 5, the compound conditional expression G ′ is G ′ =
(UC1 AND UC2) OR (UC4 AND U
C3) is assumed. From UC1 to UC4 from X ₁
If assigned to X ₄ , X ₁ and X ₂ are “1” at the same time, or X ₃ and X ₄
Are simultaneously "1", G'becomes "1". Table 6 shows this.

As described above, in the present invention, the composite conditional expression determination unit 5
Can be composed of a memory and a simple peripheral circuit as shown in FIG. On the other hand, in the prior art, since three-valued logic has to be applied to AND, OR, and NOT in the complex conditional expression, the complex conditional expression judgment unit is configured by a simple circuit as shown in FIG. It is impossible to do.

Although the result latch 11 is described as 4 bits in FIG. 2, it is needless to say that it is not limited to this value. Further, although a configuration example of the unit conditional expression determination unit 4 is not shown, it can be easily configured by a person who is familiar with the present technical field.

Further, in this embodiment, the search condition expression is converted in the data content search device, but the converted search condition expression in the main body device 9 in FIG. 3 may be applied to the data content search device 2.

〔The invention's effect〕

As described above, in the present invention, the equivalence with the original search condition expression is preserved as the search preparation operation.
Convert to a format that does not include NOT in the compound conditional expression, and when executing the search processing, if the target field value is a blank value in the judgment of the unit conditional expression, the judgment result of the unit conditional expression is set to "not satisfied", In the judgment of the composite conditional expression, by applying binary AND and OR operations, the unit conditional expression judgment unit and the composite conditional expression judgment unit can all be configured with binary logic, which has the advantage that the circuit can be simplified. .

[Brief description of drawings]

FIG. 1 is a diagram showing a connection relationship between a unit conditional expression determination unit and a complex conditional expression determination unit in the method of the present invention, and FIG. 2 is a configuration diagram of an embodiment of a complex conditional expression determination unit in the method of the present invention, FIG. Is a block diagram of a data content search processing device targeted by the present invention,
FIG. 4 is a diagram showing a configuration example of a record to be subjected to a data content search process, and FIG. 5 is a diagram showing a connection relationship between a unit conditional expression determination unit and a complex conditional expression determination unit in the conventional method. 1 ... Secondary storage device, 2 ... Data content search device, 3 ... Secondary storage control unit, 4 ... Unit conditional expression determination unit, 5 ... Complex conditional expression determination unit, 6 ... Record buffer unit, 7 ... I / O interface Control unit, 8 ... Common control unit, 9 ... Main body device.

Claims (1)

[Claims] 1. A unit condition expression for specifying a selection condition for each field value, or between different fields, for a large number of record groups consisting of a plurality of fields in which some field values are allowed to be blank values. A unit conditional expression that specifies a selection condition for the value of and a search conditional expression that is composed of a composite conditional expression that connects these plural unit conditional expressions with AND, OR, and NOT is specified, and a record group that satisfies the composite conditional expression is specified. In the search processing device that selects and outputs,
As a search preparation operation, N in the given compound conditional expression
A unit conditional expression to which OT is added is converted into a unit conditional expression in which the determination result (“established”, “not satisfied”) is reversed, and the equivalence with the original search conditional expression is preserved.ゝ N
With the compound conditional expression not including OT, after the search operation is started, the judgment result of the corresponding unit conditional expression in which the corresponding field is a blank value is set to "not satisfied" instead of "undefined". A method for determining a retrieval condition, characterized in that a compound conditional expression is determined by performing a logical operation based on a binary logic of "established" and "not established".