JPH06324919A - Performance evaluation method - Google Patents

Abstract

(57) [Abstract] [Purpose] A method for evaluating system performance under various conditions in order to find conditions under which an application program operates efficiently. A performance evaluation method capable of evaluating performance information under various conditions defined. [Structure] A history of table access instructions issued by an operating application program is stored (step a), pseudo-changed storage structure or resource definition data is input (step b), and performance parameters are obtained from them. It is calculated (step c) and output (step d).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of evaluating the system performance under various conditions in order to find the conditions under which an application program operates efficiently in a system consisting of a database, a database management system and an application program. . The conditions include the storage structure of data stored in the database and the definition of resources such as a buffer pool, a log buffer, and a temporary log.

[0002]

2. Description of the Related Art In a database, a storage structure such as a storage structure by hashing, a storage structure with an index of a B-tree structure, or the like is adopted in order to enable quick access to a large amount of data. Each method has advantages and disadvantages, and the application program can be efficiently operated by adopting an optimum storage structure according to the nature of the application program and the nature of the data.

Since the database is usually stored in an external storage device such as a disk which is slow to access, a buffer pool is provided on the memory and the database is accessed through the buffer pool to shorten the effective access time. There is. Further, a temporary log area for enabling recovery from a failure is provided on the external storage device, and a log buffer for writing to this is also provided on the memory. Therefore, by optimally defining the numbers and sizes of these buffer pools, log buffers, temporary logs, and other resources on a memory and a disk with a finite capacity, the operation of the system becomes efficient, and as a result, the application program Can be operated efficiently.

Whether the operation of the application program and the database system is optimum depends on the CPU time and the actual I / O.
It can be determined by evaluating performance information such as the number of times of O, the use efficiency of the buffer, and the operating status of the daemon. To find the optimal storage structure and resource definition,
The process of evaluating the performance information while changing the storage structure and resource definition and determining the definition of the storage structure and resource that gives the best performance information is called "tuning".

In the conventional tuning process, a method of actually operating an application program and evaluating the performance information while changing the storage structure and the definition of the resource has been adopted.

[0006]

In the conventional tuning, if tuning is performed during actual operation, there is a problem that the operation must be stopped every time the definition of the storage structure and the resource is changed. Therefore, an object of the present invention is to provide a performance evaluation method capable of evaluating performance information under various conditions of storage structure and resource definition without stopping the operation of the system.

[0007]

According to the present invention, a database in which data is stored according to a predetermined storage structure,
A database management system for managing the database, a resource given a predetermined definition, and at least one application program for accessing the data in the database using the resource under the control of the database management system. A performance evaluation method for evaluating the performance of a system, wherein a history of access to the data by the application program during operation of the application program is stored, the storage structure is pseudo-modified, and the stored There is provided a performance evaluation method characterized by evaluating the performance of a system in a pseudo modified storage structure based on a history and the pseudo modified storage structure.

According to the present invention, a database in which data is stored according to a predetermined storage structure, a database management system for managing the database, a resource to which a predetermined definition is given, and a database under the control of the database management system. What is claimed is: 1. A performance evaluation method for evaluating the performance of a system comprising at least one application program for accessing data in the database using the resource, wherein the application program stores the data while the application program is operating. A history of access to the resource, pseudo-modify the definition of the resource, and based on the stored history and the definition of the pseudo-modified resource, A performance evaluation method characterized by evaluating performance is also provided. That.

[0009]

The performance is evaluated from the access history of the application program and the definition of the pseudo-changed storage structure or resource. Therefore, it is possible to evaluate the performance under various conditions without stopping the operation of the system. You can

[0010]

FIG. 1 is a block diagram showing a conceptual configuration of a database system provided with a performance evaluation unit 10 according to the present invention. The disk 12 has a storage area for the database 14 and a temporary log 1 for recovery from a failure.
Six areas are provided. An area of the buffer pool 22 is provided on the memory 18 in order to shorten the time required for the application program 20 to refer to and update the database 14. A temporary log 1 is also stored on the memory 18.
A log buffer 24 is provided for writing to the data. The inventory management daemon 26 functions to write a part of the contents of the buffer pool 22 to the database 14 by using the free time of the CPU to create a free area in the buffer pool 22. The log daemon 28 writes from the log buffer 24 to the temporary log 16. Since the temporary log 16 recovers from the failure, the temporary log 16 is for storing the database update command until the end of each transaction in the non-volatile memory. The database management system 30 is in charge of controlling and managing the above operations.
It is obvious to those skilled in the art that the performance evaluation unit 10,
Application program 20, daemon 26, 2
8. The database management system 30 is realized by software that operates in parallel on a general-purpose computer.

FIG. 2 is a flowchart of the performance evaluation processing by the performance evaluation unit 10. First, the history of issuing an instruction to access the table in the database 14 by the operating application program 20 is collected and stored within a predetermined time (step a), and then the storage structure of the table or the pseudo definition of the resource definition. Change data is input (step b). The table storage structures include the following types, for example, one for each table
Select one and enter.

B) Heap b) Hash c) B-tree In addition, the items that can be defined for resources are as follows, for example. B) Size of temporary log 16 (Fig. 1) b) Number of log buffer 24 c) Size of log buffer 24 d) Number of buffer pool 22 e) Size of buffer pool 22 Pseudo-changed data is stored The performance parameter is calculated based on the history of the table access instruction present and the condition changed in a pseudo manner (step c). In this case, the table access instruction is pseudo-executed along the history under pseudo changed conditions to obtain the performance parameter, or the performance parameter is algebraically calculated using a predetermined calculation formula. The obtained performance information is output on the display (step d).

The performance parameters to be output when the stored information is changed, that is, the search performance parameters related to the storage structure are as follows. B) CPU time required by the application program b) Number of scans to the table c) Number of references to the buffer pool 22 d) Number of actual I / Os to the disk 12 Performance parameters that should be output when the resource definition is changed, That is, as an example, the search performance parameters related to the definition of resources are as follows.

A) Ratio of the number of actual reads to the disk 12 with respect to the number of times the buffer pool 22 is referred to b) The log buffer 24 with respect to the number of log buffers 24
C) The ratio of the maximum usage of the temporary log 16 to the size of the temporary log 16 d) Operation status of the daemon

[0015]

As described above, according to the present invention,
It is possible to evaluate the performance when changing the storage structure and / or the resource definition without stopping the operation of the system.
Efficient tuning is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a conceptual configuration of a database system including a performance evaluation unit 10 according to the present invention.

FIG. 2 is a flowchart showing a process of a performance evaluation unit 10.

Claims (2)

[Claims] 1. A database in which data is stored according to a predetermined storage structure, a database management system for managing the database, a resource to which a predetermined definition is given, and the resource is used under the control of the database management system. A performance evaluation method for evaluating the performance of a system including at least one application program for accessing data in the database, the history of access of the data by the application program during operation of the application program. And pseudo-altering the storage structure, and evaluating the performance of the system in the pseudo-altered storage structure based on the stored history and the pseudo-altered storage structure. And the performance evaluation method. 2. A database in which data is stored according to a predetermined storage structure, a database management system for managing the database, a resource to which a predetermined definition is given, and the resource is used under the control of the database management system. A performance evaluation method for evaluating the performance of a system including at least one application program for accessing data in the database, the history of access of the data by the application program during operation of the application program. And pseudo-modify the definition of the resource, and evaluate the performance of the system in the definition of the pseudo-modified resource based on the stored history and the definition of the pseudo-modified resource. A performance evaluation method characterized by the following.