JPH07104807B2 - Control method for data with multiple names - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] In the present invention, in a data set composed of a member section and a directory section, a plurality of names are given to one member in the data set. The present invention relates to a data storage method suitable for copying a data set in an existing system.

[Conventional technology]

Conventionally, when a member of a data set composed of a member section and a directory section has an alias, the following method is used, for example.

(1) Method without correspondence information between real name and alias If a real name T and aliases A, B, and C exist for one member, the directory entry of T is named T as shown in FIG. It has the member position information m1, and the directories A, B, and C also have the names A, B, and C and the member position information m1. However, these directory entries do not have information about the correspondence between the directory entries. Therefore, the correspondence between real name and alias is
It can be known only by whether or not the position information of the members held by each directory entry is the same.

(2) Correspondence method using the real name / alias position information chain When the real name T and the aliases A, B, and C exist for one member, only the directory entry of T as shown in FIG. It has m1 and has only the position information d2 of the directory entry of A among the directory entries of the three aliases. The directory entries A, B, and C have the location information d1 of the directory entry of T and the location information of the directory entries of other aliases.
They are in a chained state by position information in the order of C. Therefore, the correspondence between the real name and the alias can be known by tracing the chain of the directory entry of the alias from the directory entry of the real name.

The publicly known document is "Program Product VOS3 / ES Management Explanation" Manual 60.12 published by Hitachi, Ltd.

[Problems to be solved by the invention]

 The two conventional methods have the following problems.

(1) When a member having a system alias that does not have real name / alias correspondence information is moved or referred to, it is necessary to know the correspondence between the real name of the member and all aliases. When a real name is given from the outside when moving or referencing, since there is no correspondence information between the real name and the alias, the directory entry corresponding to all the members in the dataset is read to find the alias, and the member position information in each directory entry is read. If is the same as the real name, it is determined to be an alias of the member. Therefore, in terms of performance,
The processing load is very large.

(2) Correspondence method by location information chain of real name and alias When moving or referring to a member having an alias as in (1), the alias is obtained by processing the chain of the real name of the member and the directory entry of the alias. In this process, the number of times the directory entry is read is equal to the number of member names. This method is (1)
Better, but with a large number of aliases, performance is degraded. Both (1) and (2) have performance problems, and it is an object of the present invention to improve this performance.

[Means for solving problems]

The above object is achieved by providing an alias storage unit in the directory entry of the real name.

[Action]

The alias storage unit provided in the directory entry of the real name stores all aliases of the member. As a result, all the aliases of the relevant member are obtained just by reading the directory entry of the real name, so there is no need to read the directory entry of the alias.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1, 4, and 5.

FIG. 1 shows a data set composed of a member section and a directory section in this embodiment. When a member having the name T is created in this data set with aliases A, B, and C, the member is n1 of the member section,
The T, A, B and C directory entries of the member are stored in d1, d2, d3 and d4 of the directory section. The directory entry of T has a name of T, member position information m1 and
The names A, B, and C are stored, and the directory entry of each alias stores the name and member position information m1.

FIG. 4 and FIG. 5 are for explaining the process of copying the data set of FIG. 1 to make another data set. Specifically, FIG. 4 is a flowchart of a process for copying a member of a data set as shown in FIG. 1 to another similar data set with an alias, and FIG. 5 shows a copy source data set at that time. It is a block diagram in case data set 1 and copy destination data set are data set 2.

When there is a copy command designating the real name T of the data set, the process of FIG. 4 is started. First, the real name directory entry of the member of the directory portion of the data set 1 is input to the main memory in the processing device (a). Next, according to the position information of the member in the input real name directory entry, the member is input to the main memory from the member section of the data set 1 (b). Then, the member is output to the member section of the data set 2 (c). Next, in (a), the positional information of the member of the real name directory entry input in the main memory is updated to the positional information of the member of the member part of the data set 2, and the real name directory entry is output to the directory part of the data set 2. (D). Furthermore (e)
Based on the alias of the real name directory entry input in (a), one alias and an alias directory entry storing the position information of the member on the data set 2 are stored in the main memory for each alias. Create two and data set 2
(E). This allows
Copying is possible without the input processing of each alias directory entry for obtaining an alias between (b) and (c).

〔The invention's effect〕

According to the present invention, since the position information of the member and all aliases can be known by reading the directory entry of the real name only once, the performance can be dramatically improved as compared with the conventional method.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention, and FIG.
Fig. 3 is a schematic diagram of a conventional system without real name / alias correspondence information. Fig. 3 is a schematic diagram of a conventional system real name / aliasing position information chain correspondence system. Fig. 4 is a data set to which the present invention is applied. FIG. 5 is a flow chart of copying, and FIG. 5 is a configuration diagram of copying of a data set to which the present invention is applied. d _{1 to} d ₄ …… Directory entry, T …… Member's real name, A, B, C …… Member alias, m ₁ …… Member

Claims (1)

[Claims] 1. A member section for storing a plurality of independent data groups (hereinafter referred to as members) and a directory section for storing information (hereinafter referred to as a directory entry) regarding the name and storage position of each member. In the data processing system having a data set, the member has a plurality of names, and a directory entry having a name and the storage location information of the member is provided for each name. A method of controlling data having a plurality of names, characterized in that another name is stored and a directory entry having another name is searched for and read based on the other name in the directory entry having the representative name.