JPS6373327A - Processor for data content retrieval - Google Patents

Abstract

PURPOSE:To accurately decide a retrieval conditional equation by encoding the decided result of a unit conditional equation with two bits, combining the results of the unit conditional equation in which a composite conditional equation is realized and setting it in a RAM. CONSTITUTION:Three values 'realized', 'not realized', and 'indefinite' that are the decided results of the unit conditional equation of a unit conditional equation deciding part 4, are encoded with two bits. A table having all of combination possible to be taken as the decided results of the unit conditional equation as entries, is prepared in the RAM13 provided in a composition conditional deciding part 5. And as the preliminary operation of a data content retrieval processing, the 'realized' value is posted in advance in the entry in which a given composite conditional equation is realized. Next, after the retrieval of the content is started, the entry corresponding to the decided result of the unit conditional equation is read out at every record, and the realization of the composite conditional equation is decided based the content. In this way, it is possible to accurately decide the retrieval conditional equation.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is capable of searching only a group of records having contents that match a given search condition expression from among a huge group of records stored in a secondary storage device, etc. The present invention relates to a data content search processing device that selects and extracts data, and particularly relates to a method of configuring a search condition expression determination unit.

[Conventional technology]

Figure 1 shows an example of the configuration of a data content search processing device that selects and outputs only a record group whose content matches a specified detection condition expression from a huge group of records stored in a secondary storage device, etc. show. In FIG. 1, 1 is a secondary storage device for storing record groups, 2 is a data content search processing device, and 9 is a main device. The data content search processing device 2 includes a secondary storage control unit 3 that controls reading and writing of data in the secondary storage device 1, and determines whether a unit conditional expression given for each field of the read record group holds true or not. a unit conditional expression determination unit 4 that uses the determination result of the unit conditional expression to determine whether a given compound conditional expression holds true or not; a compound conditional expression determination unit 5 that temporarily stores the read record; A record buffer section 6 that selects and temporarily stores only the record group for which the conditional expression is satisfied, an I10 interface control section 7 that transfers the record group selected by the record buffer section 6 to the main unit 9, and overall control and search of these. It is composed of a common control section 8 that performs preparation processing.

FIG. 2 shows an example of the structure of records targeted by the data content search processing device 2. In 22, the records are Fl, F2, .
F3. An example is shown in which the field consists of five fields, F4 and F5. Table 1 shows an example of the search condition expression for the record to be searched.

” Unit conditional expression 1 (UCI) and unit conditional expression 2 (UCI) in this example
2) and unit conditional expression 3 (UC3), respectively, field F1 is equal to constant C□, field F2 is greater than field F3, and field F4 is constant C
The condition is specified that the number is 2 or less. Complex conditional expression (
G) specifies that the search conditional expression is satisfied if both UCl and UC2 hold true, or if UCI does not hold and UC3 holds true.

The data content search processing device 2 shown in FIG. 1 processes a record group having the format shown in FIG.

It is determined whether the search condition expression shown in Table 1 is satisfied, and only records that are satisfied are selected and output.

That is, the unit conditional expressions UCI, UC2, and UC3 are sequentially determined by the unit conditional expression determination section 4, and the composite conditional expression G is determined by the composite conditional expression determination section 5 using the determination results.

In this case, if the field targeted by the unit conditional expression has a specific value, unit conditional expression determination 4 determines whether it is true (T) or not true (F) as described above. On the other hand, if the field does not have a specific value (in this case, the field is said to be a "blank value (null) J"), it is impossible to determine whether the unit conditional expression holds true or not, so it is ''(M), but conventionally, the determination result is T.

In order to avoid increasing the circuit scale when the three values of F and M are used, F is used even when the value is undefined. That is, in the conventional device, the output of the unit conditional expression determining section 4 was two values, T and F. Then, in the compound condition large-format running section 5, T which is the output of the unit conditional expression determination section 4.

Regarding the binary values of F, AN according to the given compound conditional expression
Logical operations of D, OR, and NOT are executed, and when the final result is established (T), it is determined to be an output record.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, a logical contradiction may occur in which the complex conditional expression is determined to be true and is set as an output tuple, even though the result of the judgment on the complex conditional expression is originally undefined and does not become an output tuple. That is, in the compound conditional expression, tJc of the example in Table 1
If the target field of the unit conditional expression to which NOT is added is a blank value, as in l, the UCI judgment result is originally undefined (M), and its negation (NOT) is also M, but
In the prior art, M is reported as F to the complex conditional expression determination unit, so it becomes T due to NOT. Therefore, in the example of Table 1, if UC2 is F and UC3 is T, the compound conditional expression should originally be M, but NO
TUCI becomes T, and the complex conditional expression is determined to be T by AND with UC3.

To avoid this, it is necessary to disallow blank values as field values or to not use NOT in complex conditional expressions, and only very limited data content search processing is possible.

An object of the present invention is to avoid the above-mentioned usage restrictions by using three values of T, F, and M in the unit conditional expression determination section, and in which the three values of T, F, and M are output in the compound conditional expression determination section. It is an object of the present invention to provide a data content retrieval processing device that uses a three-value logic decision construction method and has a small circuit scale that enables operations equivalent to the AND, OR, and NOT operations of value logic.

[Means and effects for solving the problem] The present invention is directed to solving the problem by determining whether the unit conditional expression is determined as "P holds true".

The three values ``unsatisfied II, LL indeterminate'' are encoded in 2 bits, and a table is prepared in random access memory (RAM) that has entries containing all possible combinations of the unit conditional expression determination results, and data content search processing is performed. As a preparatory action, first write "true" in the entry for which the given compound conditional expression is true, and after starting the content search process, the corresponding judgment result of each unit conditional expression is entered for each record. The system reads the entry for which the compound conditional expression is true and determines whether the compound conditional expression is satisfied based on the contents of the entry.

〔Example〕

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

In the embodiment of the present invention, the overall configuration of the data content search processing device is as shown in FIG.

In the case of the present invention, the unit conditional expression determination unit 4 determines whether the unit conditional expression given to each field of the search target record group is satisfied (T), not satisfied (F), or indefinite (M), and The three values of expression judgment results, ie, established, not established, and indefinite, are divided into 2.
Encode and output in bits. Figure 3 shows an example of this encoding, where the code II OOII is expressed in 2 bits.
, "01 II, 1 (10", """ (7), "00" is undefined (M), "01" is not established (F), I
I 10 II indicates that it is established (T), and It " II indicates that it is not used.

FIG. 4 is a block diagram of an embodiment of the complex conditional expression determining section 5 in the present invention, and shows a case where the maximum allowable number of unit conditional expressions is four. In FIG. 4, 10 is a signal line that transfers the determination result of the unit conditional expression, " is a result latch group that stores the unit conditional expression determination result (8 bits) propagated by the signal line 10, and 12 is a result latch group" 13 is a random access memory (RAM), 14 is a write line for RAM 13, 15 is a read line for RAM 13, 16 is for determining "0" or 1" of RAM read data. 17 is a signal line that transfers the establishment of the complex conditional expression, and 1 is a set of result latches that stores the judgment result (2 bits) of one unit conditional expression.

Figure 5 assumes that the unit conditional expression judgment results as shown in Figure 3 are encoded, and when the search conditional expressions shown in Table 1 are given, the R
This shows the contents to be set in AM13. In FIG. 5, 14 indicates the address of the RAM 13. 1
41, 142, and 143 are bits corresponding to the result latches for unit conditional expressions UC1, UC2, and UC3, respectively, of the result latch group, and 144 is a bit to which no unit conditional expression is assigned. 15 is a bit for each of address 14. It shows the determination result of each unit conditional expression corresponding to the value.In other words, the address "00010010" is UCI, UC2, U
This corresponds to the case where C3 is F, M, and T, respectively. Also, the address "OOO10"0" is F for UCI, UC2, and UC3, respectively.

This corresponds to cases F and T. The same applies below. 151-1
The set of determination results of unit conditional expressions shown in 56 are all cases where the compound conditional expression is satisfied, and in this case, the corresponding entry in the RAM 13 is set to "1", and the other entries are set to "1". is set to 0''.

Next, the operations shown in FIGS. 1 and 4 will be explained. First, prior to data content search processing, a preparatory operation is performed in accordance with a given search condition expression under the control of the common control unit 8.

In this preparatory operation, first, each latch "1" of the result latch group "1" is allocated corresponding to each unit conditional expression. Next, N Q " of all bits of the result latch group ", LL I II
Among all the combinations (2"=256 in this example), the RAM corresponding to the combination for which the given compound conditional expression is satisfied
13 entries (151 to 156 in the example of FIG. 5) are set to "1" to indicate that the complex conditional expression is satisfied. RAM13
The other entries are set to "0". This completes the preparation operation, and data content search processing can now be performed.

After starting the data content search process, the secondary storage device control unit 3 reads out a group of records to be searched from the secondary storage device 1 and temporarily stores them in the record buffer unit 6. For each record, all unit conditional expressions are judged in the unit conditional expression judgment section 4, and the result is set in the result latch group "in the compound conditional expression judgment section 5 via the signal line 10.All results When the latches are set, the contents of the resulting latch group are applied to the address terminal of the RAM 13 via the address line 12, and the corresponding entry in the RAM 3 is read out. Note that a result latch to which a unit conditional expression is not assigned is “0”.
The read data of the RAM 13 is given to the determination circuit 16 via the read line 15 and is fixed to """.
0 II is determined.

Then, if the record is "1", the compound conditional expression is satisfied, and the record is determined to be an output record, and the record is held in the record buffer section 6. On the other hand, "0" is determined as an output record.
II, the record is stored in the record buffer section 6.
will be discarded.

Every time the number of records matching the search conditions held in the record buffer unit 6 reaches a certain capacity, the record group is transferred to the main unit 9 via the I10 interface control unit 7.

Now, in the example of Table 1, the determination results will be examined with reference to FIG. 5 in the case where UCI, UC2, and UC3, which were explained as causing a logical contradiction in the prior art, are M, F, and T, respectively. The corresponding address in this case is “0000”
0 “0”, and the corresponding RAM entry is u OJ
It is l. Therefore, the search condition expression is not satisfied,
Does not cause logical contradictions.

In this way, in this embodiment, the determination result of the unit conditional expression is encoded in 2 bits, and the establishment of the compound conditional expression is set in the RAM entry corresponding to the combination of the unit conditional expression determination results for which the compound conditional expression is satisfied. Since the determination is made by setting the search condition expression, there will be no logical contradiction in the determination of the search condition expression, even if there is no usage restriction that is required in the past. Furthermore, the complex conditional expression determination section of this embodiment is comprised only of a RAM and its peripheral circuits, and the circuit scale is small.

In addition, in the explanation of the example, the maximum allowable number of unit conditional expressions is 4.
However, the present invention is not limited to these.

〔Effect of the invention〕

As explained above, in the present invention, the determination result of a unit conditional expression (holding, not holding, indeterminate) is encoded in 2 bits, and the RA
Since the combination of unit conditional expression judgment results that satisfy the compound conditional expression is displayed in M and the compound conditional expression judgment equivalent to three-value logic is performed, it is not necessary to write NOT in the compound conditional expression as in the past. It is possible to correctly determine the search condition expression without setting restrictions such as not using it or not allowing blank values as target data. Furthermore, since the complex conditional expression determination section is comprised only of a RAM and its peripheral circuits, it has the advantage of having a small circuit size and fast determination speed.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the data content search processing device of the present invention, FIG. 2 is a diagram showing an example of the configuration of records targeted for data content search processing, and FIG. 3 is a unit condition in the present invention. FIG. 4 is a diagram showing an example of the coding of the expression determination result, FIG. 4 is a diagram showing an example of the configuration of the complex conditional expression determination section in the present invention, and FIG. 5 is a diagram showing an example of the contents of the RAM in FIG. 4. DESCRIPTION OF SYMBOLS 1... Secondary storage device, 2... Data content search processing device, 3... Secondary storage device control section, 4... Unit conditional expression determination section, 5... Complex conditional expression determination section, 6...
・Record buffer unit, 7... I10 interface control unit, 8... Common control unit, 9... Main unit,
10... Unit conditional expression judgment result signal line, "... Unit conditional expression judgment result latch group, 12... RAM address line,
13...Random access memory (RAM),
14...Writing line, 15...Reading line, 16.
. . . Judgment circuit, 17 . . . Compound conditional expression establishment signal line. -1-cho TF Do-1155'-TT
156 to T

Claims (1)

[Claims] (1) A search condition that targets a large group of records consisting of multiple fields and consists of a unit conditional expression that specifies a search condition for any field or multiple fields, and a complex conditional expression that is a logical expression that uses the unit conditional expression as an element. In a data content search processing device that is given an expression and selects and outputs only a group of records for which the search conditional expression holds true, the three-value states of “true,” “not true,” and “indeterminate” that are the judgment results of the unit conditional expression are is expressed in code, a group of result latches that holds the coded unit conditional expression judgment results, a random access memory that can read and write the contents of the group of result latches as an address, and a memory that is read from the memory. and a means for determining a value, as a preparatory operation for data content search processing, to determine, based on a given compound condition, a combination that satisfies the compound conditional expression among all possible combinations of the contents of the result latch group. Information indicating "true" is written to the entry in the memory whose address is , and information indicating "false" is written to the other entries. After starting the data content search process, multiple unit conditional expressions are determined for each record, and the judgment is made. When the results are aligned in the result latch group, the corresponding entry in the memory is read using the combination of the result latch groups as an address, and based on the content of the entry, it is determined whether a compound conditional expression is satisfied, and an output record is determined. Data content search processing device.