JPH05113919A - Sql preprocessing device - Google Patents

Abstract

PURPOSE:To improve system performance by converting plural structured query language (SQL) sentences into a single data base processing request thereby making an access to a data base with the small communication value in the case of using the data base. CONSTITUTION:A preprocessing device 11 reads a single SQL sentence out of an SQL program 10 and then sends it to a state controller 13. Then the device 11 inquires the information on the SQL sentence stored in an SQL sentence storage 13 and also the present state of a state storage 14. The controller 12 decides whether the SQL sentence received from the device 11 can request or not a data base processor together with the hitherto SQL sentences based on the information received from both storages 12 and 14. Based on this deciding result, the device 11 processes the storage contents of an internal form storage 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an SQ that creates a program for accessing a database using SQL.
The present invention relates to an L preprocessing device.

[0002]

2. Description of the Related Art FIG. 3 shows an SQL preprocessing apparatus according to the prior art, and FIG. 4 shows execution of database access.
Most programs for accessing the database are written in a language called SQL. Conventionally, such a program has been processed by a device called a prepros device and converted into a program for actually accessing the database.

In FIG. 3, first, the SQL preprocessing device 31 reads out only one SQL statement 301 from the SQL program 30. SQL preprocessing device 3
1 creates an internal format 302 for actually accessing the database based on the contents of the SQL statement 301, and notifies the database access requesting device 32 of the internal format 302.
The database access requesting device 32 sequentially stores the notified internal format 302 in the device. Thereafter, the SQL preprocessing device 31 performs the same processing for all the SQL statements 301 included in the SQL program 30, and outputs the sequence of the internal format 302 for performing the access processing to the database. It is stored inside the tabular access request device 32.

Next, in FIG. 4, the data base access requesting device 41 follows the internal format 401 for the data base access created by the SQL preprocessing device 31 to the data base processing device 42. Send an access request 402. The database processing device 42 requests access 402
The access processing to the database is executed based on the contents of the above, and the database access result 403 is obtained, and the database is accessed.
It is returned to the access request device 41. Below, the database
The access requesting device 41 sequentially reads the internal format 401 until data stored in the internal format 401 is exhausted.
The database access request 402 is transmitted to the database processing device 4
2 and the process of obtaining the data base access result 403 is repeated.

[0005]

However, as shown in FIG. 4, the number of SQL statements 301 included in the SQL program 30 in the conventional method is the same as the number of SQL statements 301 from the database access request device 41. A processing request is sent and the data
Since the result is returned from the database processing device 42, there arises a problem that the amount of communication between the database access request device 41 and the database processing device 42 increases. Particularly, when the database access requesting device 41 and the database processing device 42 are connected by a low-speed communication line, there is a problem that the performance is deteriorated due to communication delay due to a large amount of communication. Occurs.

The present invention has been made in view of the above points, and in order to solve the above problems, the SQL preprocessing device 31 converts a plurality of SQL statements 301 into an internal format for one processing request. By adding the function for
It is an object of the present invention to provide means for improving the performance of the system by reducing the amount of communication between the database access request device 41 and the database processing device 42.

[0007]

In order to solve the above problems, the present invention provides a conventional preprocess apparatus 1 as shown in FIG.
1. SQL statement storage device 1 for temporarily recording SQL statement in 1
2, state management device 13, state storage device 14, database
An internal format storage device 15 for recording the internal format for access is provided.

[0008]

In the present invention, by providing the above device,
The state management device 13 checks the dependency relationship of each SQL statement while looking at the state storage device 14, and if a condition capable of collecting a plurality of SQL statements into one internal format is satisfied,
Converts in a single internal format. Subsequently, the data base access requesting device 17 is stored in the internal format storage device 15.
Sent to. In this way, the number of accesses to the database processing device 42 can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of the present invention, and FIG. 2 shows a flow of information in the embodiment. The SQL preprocessing device 16 uses the SQ read from the SQL program 10.
A preprocessing device 11 for converting an L statement into an internal format, and an SQL statement storage device 1 for temporarily storing the read SQL statement.
2. The SQL sentence storage device 12 stores the newly read SQL sentence.
State management device 13 for determining the dependency relationship with the previous SQL statement stored in, and a state storage device for storing the current state and storing information for the state management device 13 to make the determination 14, an internal format storage device 15 for temporarily storing the internal format for data base access created by the preprocessing device 11.

FIG. 2 shows the flow of information for SQL program conversion according to the embodiment. First, the pre-processing device 21 sends an S sentence of one sentence from the SQL program 20.
The QL sentence 201 is read. The preprocessing device 21 is
The QL sentence 201 is sent to the state management device 23 202. The state management device 23 inquires 203 of the SQL statement storage device 22 about the currently stored SQL sentence, and at the same time inquires 204 the state storage device 24 about the current state.
The state management device 23, based on the information 203 from the SQL statement storage device 22 and the information 204 from the state storage device 24, receives the SQL statement 20 newly received from the preprocessing device 21.
2 is the existing S stored in the SQL statement storage device 22.
It is determined whether or not the QL sentence and the sentence can collectively be requested to the database processing device 42. This is called superimposition possibility determination. The determination result of the superimposition possibility is notified to the preprocessing device 21. Based on the determination result, the preprocessing device 21 processes the stored contents of the internal format storage device 25, and the state management device 23 processes the stored contents of the SQL statement storage device 22 and the state storage device 24, respectively.

The conditions for determining the possibility of superimposition are as follows. When the database processing device 42 collectively processes the SQL statement stored in the SQL statement storage device 22 and the SQL statement 202 newly received from the pre-processing device 21 into one sentence, these statements are processed. These SQL statements may be converted into an internal format for a single processing request if the processing results are the same as when the SQL statements are executed separately. Preprocessing equipment 2
1 performs the following operations based on the determination result.

If the superposition is possible, the internal format storage device 25
208 retrieves the internal format stored in. The SQL statement 202 newly sent to the state management device 23 is added to the extracted internal format 208, converted into an internal format combined into one request, and stored again in 25 209. In this case, the state management device 23 requests 205 the SQL statement storage device 22 to additionally store the newly sent SQL statement 202. At the same time, the state management device 23 changes the state storage device 2
4 stores information indicating that the superimposition process is currently being performed.

If superimposition is not possible, the state management device 23 uses S
Request 205 to discard the SQL sentence stored so far in the QL sentence storage device 22 and store the newly sent SQL sentence 202. Furthermore, the state change device 24 is notified of the state change. The preprocessing device 21 is the internal storage device 2.
The internal format stored in No. 5 is taken out, notified to the database access requesting device 27, and stored internally. Subsequently, the new SQL statement 202 is converted into the internal format and requested to be stored in the internal format storage device 25.

[0014]

As described in detail above, according to the present invention, the following effects are expected. SQL of the present invention
With the pre-processing device, it is possible to convert a plurality of SQL statements into a single database processing request. Therefore, when the database is used using SQL, the communication volume is smaller than before. The database can be accessed and the performance of the system can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing a flow of information in the embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional SQL preprocessing apparatus.

FIG. 4 is an execution example of a database access according to a conventional technique.

[Explanation of symbols]

 10 SQL Program 11 Pre-Processing Device 12 SQL Statement Storage Device 13 State Management Device 14 State Storage Device 15 Internal Format Storage Device 16 SQL Pre-Processing Device 17 Data Base Access Request Device

Claims (1)

[Claims] 1. A data accessible by SQL language.
In an SQL preprocessing device having a tabular processing device, a first means for storing the read SQL statement, a second means for storing the processing state, and a stored SQL statement and the read SQL statement. A third means for determining the possibility of superimposing an SQL sentence from the statement and the processing state; and a fourth means for storing the internal format of the SQL sentence, wherein the third means is A means for determining superimposition possibility by referring to the recording by the first means and the second means and converting a plurality of SQL sentences into a single database-accessible internal format. S characterized by having
QL pre-processing equipment.