JPH07101393B2 - Reorganization method - Google Patents

Description

The present invention relates to a data reorganization method in a database system of an electronic computer system.

[Conventional technology]

In a database system, data is stored in a data file as a data record, and as a data record, an index record that defines a search key that is a key value for a search is usually used. There is a via record that is accessed. Further, generally, the data file is composed of a plurality of storage units.

By the way, even if a data file is once organized according to a predetermined rule, another rule (for example, a data file in which the number of index records in each storage unit is not limited by It is often necessary to reorganize into a data file based on (for example, limiting the number of index records to a predetermined number). Conventionally, reorganization was performed by the configuration shown in FIG.

That is, in FIG. 7, the reorganizing means 2'reads all the data records from the data file 1'into the memory 5'by activating the data file reading means 4 ', and then the reorganizing means 2'. Is to activate the data file creating means 6'to perform the organization based on the new rule and store the data record in the data file 1 '.

[Problems to be Solved by the Invention]

As described above, in the conventional reorganization method, the entire data file is reorganized in a batch, so it is necessary to occupy the data file during the processing, and the database system is temporarily stopped. However, there is a drawback that it has a great impact on the users of the database system. In particular, the time required for reorganization has increased with the enormous growth of databases in recent years, and the above-mentioned drawbacks have become more serious.

The present invention has been proposed in view of the above points, and an object thereof is a reorganization method capable of performing reorganization while keeping a fixed price of a service to a minimum without occupying an entire data file. Is to provide.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has a data file composed of a plurality of storage units including an index record and a via record, and the number of index records included in each storage unit matches the predetermined number as much as possible. In the method of performing reorganization as described above, a storage unit reading unit that waits for startup and reads the data records in the storage unit that is the target of partial reorganization into the memory at once, and a unit that reads data records in the memory after starting Storage unit creation means for recreating a new storage unit in which the number of index records matches the predetermined number from the data records, and recreating at most one storage unit in which the number of index records does not reach the predetermined number; Waiting for activation, the data record in the storage unit to be partially reorganized is placed in an occupied state, and the storage unit reading means and the storage unit are stored in the storage unit. Partial reorganization means for activating the delivery unit creation means to partially reorganize the data file and then releasing the occupied state of the data record in the storage unit recreated by the storage unit creation means; and the data file When the storage unit to be partially reorganized is sequentially determined for the storage units in the table and the partial reediting means is activated, and a storage unit in which the number of index records does not reach the predetermined number is recreated, The partial reorganization means is activated by setting the storage unit to be a partial reorganization target of the storage unit and another storage unit, and the number of index records of all the storage units in the data file matches the predetermined number. Alternatively, if only one storage unit has the number of stored index records that is less than the predetermined number and the number of stored index records of all other storage units matches the predetermined number, And a reorganization unit to terminate the knitting process.

[Action]

According to the reorganization method of the present invention, the reorganization unit sequentially determines the storage units to be subjected to the partial reorganization with respect to the storage units in the data file, and activates the partial reorganization unit. By occupying the data records in the storage unit that is the target of partial reorganization, prohibiting the user's access to the data records in those storage units,
For those storage units, the storage unit reading means is activated to collectively read the data records of the storage units into the memory, and then the storage unit creating means is activated to extract the index records from the data records read into the memory. After recreating a new storage unit whose number matches the specified number and partially reorganizing the data file, release the occupied state of the data record in this recreated storage unit and Allow access. The reorganization means performs such partial reorganization when the number of index records of all storage units in the data file matches a predetermined number, or 1
This process is repeated until only one storage unit has the number of stored index records that is less than the predetermined number and the number of stored index records of all other storage units matches the predetermined number. It should be noted that the reorganization means, when the storage unit in which the number of index records does not reach a predetermined number is recreated by the partial reorganization means, the storage unit and the other storage unit are storage units to be partially reorganized. Then, the partial reorganization means is activated.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the reorganization system of the present invention. In FIG. 1, reference numeral 1 is a data file that stores data records to be reorganized, and is composed of a plurality of storage units 11 as shown in FIG.
Each 11 contains a plurality of index records a and their associated plurality of via records b. In the figure, the data records that are associated with each other are shown connected by a solid line. Further, the via record b is managed so as to be arranged at a close position in the same storage unit as the index record a to which it belongs.

In FIG. 1, a reorganization unit 2, a partial reorganization unit 3, a storage unit reading unit 4, and a storage unit creation unit 6 are provided as other configurations. The memory 5 is the main memory of the computer system that executes the process.

FIGS. 3, 4, and 5 are flowcharts showing the processes of the reorganization unit 2, the partial reorganization unit 3, and the storage unit creation unit 6 in FIG. 1, respectively. The reorganization means 3 is activated, and the partial reorganization means 3 activates the storage unit reading means 4 and the storage unit creation means 6 as appropriate. It should be noted that the storage unit reading means 4 is a simple process of waiting for activation and reading the data records in several storage units in the data file 1 into the memory 5 all at once, and therefore is not shown as a flowchart. .

The operation of each means will be described below.

In FIG. 5, when the storage unit creating means 6 is activated,
It is checked whether or not there are enough data records in the memory 5 to create a storage unit that complies with a predetermined rule specified in advance (step 61), and if there is, a data record of one storage unit from the memory 5 is checked. Take out (step 6
2) Create a new storage unit based on a predetermined rule (step 63), and return to step 61. Also, step 61
If enough data records are crying, the remaining data records are taken out from the memory 5 (step 64), one new storage unit is created (step 65), which is not based on the prescribed rule, and the process ends. To do.

In FIG. 4, when the partial reorganization unit 3 is activated, some data units (index records and via records) in the storage units to be reorganized in order to prohibit access from the user. The records are set in the occupied state (exclusive state), the storage unit reading means 4 is activated for these storage units, and the data records in these storage units are read into the memory 5 (step 31).
Then, the storage unit creating means 6 is activated to create a new storage unit (step 32), and after partially reorganizing the data file, the occupancy state for the data record in the newly created storage unit. To allow users to access those data records,
The process ends. That is, by the above processing, the plurality of target storage units are partially reorganized when viewed as the entire data file 1.

In FIG. 3, the reorganization means 2 activates the partial reorganization means 3 for some storage units at the beginning of the data file 1 (step 21), waits for the end of the processing, and waits until the end of the data file 1. It is checked whether or not the processing by the partial reorganization means 3 has been performed (step 22), and when the processing is executed to the end, all processing is ended. If it has not been executed to the end in step 22, it is checked whether or not a storage unit that does not match the rule specified in advance has been created by the execution of the partial reorganization means 3 (step 23),
If it has not been created, the partial reorganization means 3 is started for the next several storage units of the data file 1 (step 25), and the process returns to step 22. If it is determined in step 23 that a storage unit that does not conform to the rule has been created, the partial reorganization means 3 is performed for the storage unit that does not conform to the rule and the next several storage units of the data file 1. Is started (step 24) and the process returns to step 22. By these processes, reorganization is performed without occupying the entire data file 1 at the same time.

FIG. 6 specifically shows how the contents of the data file 1 are changed by the operation of the embodiment. The data file 1 is initially divided into storage units 11A, 11B, 11C, 11D. And In addition, a represented by "●" is an index record, and b represented by "○" is a via record. Also,
An example of a case in which "the number of storage units simultaneously processed by the partial reorganization unit 3 is 2 and the number of index records a in each storage unit is 2" is adopted as a rule for reorganization Is.

Then, when the reorganization means 2 starts the processing in the state of (a) at the beginning, the reorganization means 2 activates the partial reorganization means 3 for the storage units 11A and 11B in the data file 1 to perform the partial reorganization. The organization unit 3 makes the data recorders in the storage units 11A and 11B occupied, and activates the storage unit reading unit 4 for the storage units 11A and 11B as shown in (b) to store the storage units 11A and 11B.
Read all the data records in the memory into the memory 5,
Then, the storage unit creating means 6 is activated to recreate the storage unit from the data record read on the memory 5 in accordance with the above-mentioned rule, and as shown in (C), the storage unit 11A ', 11B' conforming to the rule is obtained. Reorganized into a data file 1 containing storage units 11E that do not conform to the rules, and storage units 11A ', 11B'1
The exclusive state of the data records in 1E is released, and the user can access these data records.

Here, while the storage units 11A and 11B are being reorganized, other storage units 1
Since the data records in 1C and 11D are not occupied, the user of the data file 1 can access the data records in other storage units 11C and 11D even while the storage units 11A and 11B are being reorganized. is there.

Next, the reorganization means 2 uses the storage unit 11 in the data file 1
The partial reorganization means 3 is activated for E, 11C, and the partial reorganization means 3 makes the data records in the storage units 11E, 11C occupy and for the storage units 11E, 11C as shown in (d). The storage unit reading means 4 is activated to collectively read the data records in the storage units 11E and 11C onto the memory 5, and then the storage unit creating means 6 is activated to start the above-mentioned data record from the data record read onto the memory 5. Recreate the storage unit according to the rules, and as shown in (e), the storage unit that conforms to the rules 11
The data file 1 including E'and 11C 'is reorganized, and the occupied states of the data records in the storage units 11E' and 11C 'are released so that the user can access these data records.

Here, while the storage units 11E and 11C are being reorganized, other storage units 1
Since the data records in 1A ', 11B', and 11D are not occupied, the user of the data file 1 stores the storage unit 11E,
Other storage units 11A ', 11B', 11D even during reorganization of 11C
Access to the data records in is possible.

Next, the reorganization unit 2 stores the storage unit in the data file 1.
The partial reorganization means 3 is activated for 11D, and the partial reorganization means 3 sets the data record in the storage unit 11D to the occupied state, and the storage unit reading means 4 is executed for the storage unit 11D as shown in (f). Upon activation, the data records in the storage unit 11D are collectively read into the memory 5, and then the storage unit creating means 6 is activated to recreate the storage unit from the data records read into the memory 5 according to the above-mentioned rules. , (G)
As shown in, the data file 1 containing the storage unit 11D 'that conforms to the rules is reorganized, the data records in the storage unit 11D' are released from the occupied state, and the user can access these data records. And

Here, while the storage unit 11D is being reorganized, another storage unit 11D is
Since the data records in A ', 11B', 11E ', 11C' are not occupied, the user of the data file 1 can access the data records in the storage units 11A ', 11B', 11E ', 11C'. Is possible.

Then, when the reorganization processing of the storage unit 11D is completed,
Since the processing has been completed for all the storage units 11A to 11D in the data file 1, the reorganization processing is completed.

In the example of FIG. 6, since there are even number of index records in the data file 1, it is possible to include two index records in each storage unit after reorganization. However, when the data file 1 has an odd number of index records, when the last storage unit is partially reorganized, only one index record that is less than the predetermined number of two is included. A storage unit that does not exist will be created, but this is inevitable and the reorganization means 2
Ends the reorganization process in the state where one storage unit that does not conform to such a rule is created.

Further, since the data record in the storage unit during the partial reorganization is in an occupied state, when the user requests access to the data record in the storage unit during the partial reorganization, the access request is It is necessary to wait until the exclusive state of the data record is released.

〔The invention's effect〕

As described above, in the reorganization method of the present invention,
Since the data file is partially reorganized and this process is repeated, it is possible to perform reorganization without stopping the database system without occupying the entire data file at the same time. This has the effect of minimizing the degradation of service to users.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the reorganization system of the present invention, FIG. 2 is a logical block diagram of the data file in FIG. 1, and FIG. 3 is a flowchart of the processing of the reorganization means in FIG. 4, FIG. 4 is a flow chart of the processing of the partial reorganization means in FIG. 1, FIG. 5 is a flow chart of the processing of the storage unit creation means in FIG. 1, and FIG. 6 is a diagram showing the change of the data file accompanying the reorganization. And FIG. 7 is a block diagram of a conventional reorganization system. In the figure, 1 ... Data file 11 ... Storage unit a ... Index record b ... Via record 2 ... Reorganization means 3 ... Partial reorganization means 4 ... Storage unit reading means 5 ... Memory 6 ... Storage unit creation means

Claims (1)

[Claims] 1. A data file composed of a plurality of storage units including an index record and a via record,
In the method of reorganizing so that the number of index records included in each storage unit matches as much as possible to the specified number, the data records in the storage unit that is the target of partial re-editing are collectively stored on the memory at startup. A storage unit reading means for reading and a new storage unit in which the number of index records matches the above-mentioned predetermined number are recreated from the data records read on the memory after starting up, and the number of index records becomes the above-mentioned predetermined number. A storage unit creation unit that recreates a maximum of one storage unit that does not meet, a data record in the storage unit that is the target of partial reorganization after being activated, is occupied, and the storage unit reading unit and the storage unit The data unit in the storage unit recreated by the storage unit creation unit after the storage unit creation unit is activated to partially reorganize the data file A partial reorganization unit that releases the occupied state of the card, and a storage unit that is a target of the partial reorganization is sequentially defined for the storage units in the data file, and the partial reorganization unit is activated to determine the number of index records. When a storage unit of less than the predetermined number is reorganized, the storage unit and another storage unit are set as the storage unit to be the partial reorganization target, the partial reorganization means is activated, and the data file The number of index records of all the storage units in the storage unit matches the predetermined number, or only one storage unit has the number of stored index records less than the predetermined number and the number of stored index records of all other storage units And a predetermined number, the reorganization means for terminating the reorganization process.