KR102127785B1 - Method and apparatus for providing efficient indexing and computer program included in computer readable medium therefor - Google Patents

Abstract

A method performed in a database management system (DBMS) is provided in accordance with one embodiment of the present disclosure. The method may include generating a database index structure for pointing the data storage location, based on the monitoring result information according to the monitoring algorithm in the database management system. The database index structure includes at least partially a sub index structure of the first level and a sub index structure of the second level that is lower than the first level, and the sub index structure of the second level includes a plurality of columns, The first column of the plurality of columns of the second-level sub-index structure includes key values, and the second column of the plurality of columns of the second-level sub-index structure has a ROWID value corresponding to a row of the data block. The third column of the plurality of columns of the second-level sub-index structure may include optimization index values that are set based on the monitoring result information.

Description

METHOD AND DEVICE TO PROVIDE EFFECTIVE INDEXING AND COMPUTER PROGRAM INCLUDED IN COMPUTER-readable media {METHOD AND APPARATUS FOR PROVIDING EFFICIENT INDEXING AND COMPUTER PROGRAM INCLUDED IN COMPUTER READABLE MEDIUM THEREFOR}

The present disclosure relates to a database indexing technique, and more particularly, to an index creation technique for improving DB performance.

Corporate business is rapidly expanding with the explosive growth of data and the emergence of various environments and platforms. With the advent of the new business environment, more efficient and flexible data services, information processing, and data management functions are needed. In response to these changes, research into databases to solve the problems of high performance, high availability, and scalability, which are the foundations of corporate business implementation, is continuing.

In a database management system (DBMS), data can be stored in a data store. In a relational database management system (RDBMS), such a data store may be referred to as a table. Such a table may include one or more rows, and each of the one or more rows may include one or more columns.

When the database contains a large amount of data, it may take a relatively long time to perform a query to retrieve data of interest to the user. If the database takes a long time to respond to a query, it may adversely affect the performance of the database. Accordingly, various techniques have been studied in the related art to reduce processing time in response to a query, that is, to increase the performance of a database management system.

In increasing the speed of data retrieval from the database, indexing techniques can be utilized. Such an index may refer to a data structure that increases an operation speed of a table in the database field. In the case of using an index, not only can the time required for data retrieval be reduced, but also the amount of resources consumed for data retrieval can be reduced.

In general, the index structure consists of a tree structure. The tree structure is a kind of graph, consisting of nodes and pointers to nodes. Multiple nodes cannot point to one node, but one node can point to multiple nodes. If you need to search a huge amount of stored data, comparing data one by one is inefficient. Indexing using a tree structure allows you to efficiently search for data by storing the data in sorted state. Traverse refers to a series of processes for searching an index. Traverse starts from the root node and proceeds by comparing the value of the search target and the distinguished value and finding the next pointer. When the index corresponding to the value of the search target is found through the traverse, the traverse ends.

The index may be largely classified into a B+tree (Balanced Tree) index and a bitmap index.

The B+tree index may refer to a hierarchical indexing technique into a root block, branch block, and leaf block. In the B+tree index, the leaf block has a ROWID that can access the corresponding row of the data block, and the branch block and the root block have a key value (eg, the address value of the block) that can access each lower level.

The bitmap index may refer to an indexing technique that automatically stores a column value using a bit, which is the smallest unit used in a computer, and automatically generates a ROWID using it.

Each of the B+ tree indexing technique and the bitmap indexing technique may have advantages and disadvantages due to its structural characteristics. Therefore, there is a need in the art for an efficient indexing technique to improve the performance of the DBMS in the situation of processing massive data.

(1) US registered patent US5903888 (2) US registered patent US6278992 (3) Japanese Patent Publication JP2004326404

The purpose of the present disclosure is to reduce the query processing time in the DBMS in order to meet the demands in the art described above.

The purpose of the present disclosure is to provide an efficient indexing technique in DBMS in order to meet the needs in the art.

A computer program stored in a computer-readable storage medium including encoded instructions, according to one embodiment of the present disclosure, wherein the computer program, when executed by one or more processors, causes the one or more processors to generate data. The following operations are performed to improve the search performance of the database, and the operations are: based on monitoring result information according to a monitoring algorithm in a database management system (DBMS), a database index for pointing a data storage location It may include the operation of creating a structure. The database index structure includes at least partially a sub index structure of the first level and a sub index structure of the second level that is lower than the first level, and the sub index structure of the second level includes a plurality of columns. The first column of the plurality of columns of the second-level sub-index structure includes key values, and the second column of the plurality of columns of the second-level sub-index structure includes a row of a data block. ), and the third column of the plurality of columns of the second-level sub-index structure may include optimized index values that are set based on the monitoring result information.

In accordance with one embodiment of the present disclosure, a method performed in a database management system (DBMS) is provided. The method may include generating a database index structure for pointing the data storage location based on the monitoring result information according to the monitoring algorithm in the database management system. The database index structure includes at least partially a sub index structure of the first level and a sub index structure of the second level that is lower than the first level, and the sub index structure of the second level includes a plurality of columns, The first column of the plurality of columns of the second-level sub-index structure includes key values, and the second column of the plurality of columns of the second-level sub-index structure has a ROWID value corresponding to a row of the data block. The third column of the plurality of columns of the second-level sub-index structure may include optimization index values that are set based on the monitoring result information.

Disclosed is a database management apparatus according to an embodiment of the present disclosure. The database management apparatus includes a processor that generates a database index structure for pointing a data storage location based on monitoring result information according to a monitoring algorithm in a database management system (DBMS); And a storage unit for storing the created database index structure. The database index structure includes at least partially a sub index structure of the first level and a sub index structure of the second level that is lower than the first level, and the sub index structure of the second level includes a plurality of columns, The first column of the plurality of columns of the second-level sub-index structure includes key values, and the second column of the plurality of columns of the second-level sub-index structure has a ROWID value corresponding to a row of the data block. The third column of the plurality of columns of the second-level sub-index structure may include optimization index values that are set based on the monitoring result information.

Query processing time in a DBMS may be reduced according to an embodiment of the present disclosure.

According to one embodiment of the present disclosure, an efficient indexing technique in a DBMS can be provided.

Various aspects are now described with reference to the figures, in which like reference numerals are used collectively to refer to similar elements. In the following examples, for illustrative purposes, a number of specific details are presented to provide a holistic understanding of one or more aspects. However, it will be apparent that such aspect(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more aspects.
1 shows a schematic diagram of a database management apparatus and client according to an embodiment of the present disclosure.
2 is a block diagram of a DBMS according to an embodiment of the present disclosure.
3 is a block diagram of a database management apparatus according to an embodiment of the present disclosure.
4 exemplarily illustrates a database index structure according to an embodiment of the present disclosure.
5 exemplarily illustrates different database index structures in units of partitions according to an embodiment of the present disclosure.
6 exemplarily shows a flowchart for performing efficient indexing, according to one embodiment of the present disclosure.
7 exemplarily shows means, logic and modules for performing efficient indexing, according to one embodiment of the present disclosure.
8 shows a simplified and general schematic diagram of an exemplary computing environment in which embodiments of the invention may be implemented.

Various embodiments and/or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, a number of specific details are disclosed to assist in the overall understanding of one or more aspects. However, it will also be appreciated by those of ordinary skill in the art of the present invention that this aspect(s) can be practiced without these specific details. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more aspects. However, these aspects are exemplary and some of the various methods in the principles of the various aspects may be used, and the descriptions described are intended to include all such aspects and their equivalents.

In addition, various aspects and features will be presented by a system that may include multiple devices, components and/or modules, and the like. Various systems may also include additional devices, components and/or modules, and/or may not include all of the devices, components, modules, etc. discussed in connection with the drawings. It must be understood and recognized.

As used herein, "an embodiment", "yes", "a good", "an example", etc., may not be construed as any aspect or design described being better or more advantageous than another aspect or designs. . The terms'component','module','system', and'interface' used in the following generally mean a computer-related entity, for example, a combination of hardware, hardware and software, It can mean software.

In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise or unclear in context, “X uses A or B” is intended to mean one of the natural inclusive substitutions. That is, X uses A; X uses B; Or if X uses both A and B, "X uses A or B" can be applied in either of these cases. It should also be understood that the term “and/or” as used herein refers to and includes all possible combinations of one or more of the listed related items.

Also, the terms “comprises” and/or “comprising” mean that the feature and/or component is present, but excludes the presence or addition of one or more other features, elements and/or groups thereof. It should be understood as not. In addition, unless otherwise specified or contextually unclear as indicating a singular form, the singular in the specification and claims should generally be construed to mean "one or more."

As used herein, the terms "component", "module", "system" and the like refer to computer-related entities, hardware, firmware, software, a combination of software and hardware, or execution of software. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, a thread of execution, a program, and/or a computer. For example, both the application and the computing device running on the computing device can be components. One or more components can reside within a processor and/or thread of execution, and one component can be localized within one computer, or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored therein. Components are, for example, signals having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or data via a network such as the Internet with other systems via signals and/or signals). ) Through local and/or remote processes.

Computer-readable media as used herein may include any kind of storage media in which programs and data are stored so that they can be read by a computer system. According to one aspect of the present invention, such a computer-readable medium may include a computer-readable storage medium and a computer-readable transmission medium. Computer-readable storage media include ROM (Read Only Memory), RAM (Random Access Memory), CD (Compact Disk)-ROM, DVD (Digital Video Disk)-ROM, magnetic tape, floppy disk, and optical data storage devices. It can contain. Computer-readable transmission media may include those implemented in the form of carrier waves (eg, transmission over the Internet). Additionally, such media may be distributed over networked systems to store computer readable codes and/or instructions in a distributed fashion.

It should be noted that, prior to explaining the specific contents for carrying out the present invention, a configuration not directly related to the technical subject matter of the present invention has been omitted without detracting from the technical subject matter of the present invention. In addition, the terms or words used in the specification and claims are based on the principle that the inventor can define the concept of appropriate terms in order to explain his or her invention in the best way. It should be interpreted as a concept.

The basic concept of indexing technology according to an embodiment of the present disclosure is specifically discussed in US Pat. Nos. US9626398 (2017.04.18) and US2007-0174309 (2007.07.26), the entire contents of which are incorporated herein by reference.

As described above, the index can be divided into a B+tree index and a bitmap index.

The B+tree index may refer to a hierarchical indexing technique into a root block, branch block, and leaf block. In the B+tree index, the leaf block has a ROWID that can access the corresponding row of the data block, and the branch block and the root block have a key value (eg, the address value of the block) that can access each lower level.

In B+tree index, it is a structure that has the column values of the table and the ROWID of information in the set in an ordered form, so if the physical addresses for the same value are different, the same value must be duplicated, so storage space is wasted. Can occur. That is, since the B+ tree index must store the actual column value in the index, there may be a disadvantage in managing and processing large amounts of data. In addition, in order for the B+tree index to operate efficiently, the selectivity of the column values must be good, and there may be a disadvantage that the performance of the index is not guaranteed under certain conditions. Furthermore, a B+tree index may be subject to many restrictions in a situation in which two or more indexes are used in parallel when accessing the same table. In a real DBMS work environment, user requirements can be very diverse. In order to satisfy the requirements of various types of users, it is necessary to create a B+tree index equal to the combination of all columns in the table, and in this case, the index size may be larger than the table size. When there are two B+tree indexes with good distribution, there may also be constraints for effectively using the two indexes, such as only one used for simultaneously using two or more indexes.

The bitmap index may be considered as an attempt to solve the problems of the B+tree index. The bitmap index may refer to an indexing technique that automatically stores a column value using a bit, which is the smallest unit used in a computer, and automatically generates a ROWID using it. In general, the bitmap index, after performing a table scan to find the values of the column to create the index, after the index entry with the column value, start (ROW), end (END) ROWID and bitmap is created, After the generated bitmaps are arranged in a form that is easy to be inserted into the B+ tree structure (ie, the key value and the starting ROWID order), the sorted index entries can be generated in such a way that they are inserted into the B+ tree structure. However, even in the case of a bitmap index, the bitmap entry continuously increases during the Data Manipulation Language (DML) operation, which may result in the size of the bitmap index being larger than the size of the table when performing frequent DML operations. have. In addition, the bitmap index may be inefficiently increased in size when there are many Distinct values.

According to an embodiment of the present disclosure, a technique of combining a bitmap index and a B+tree index in an efficient manner may be provided. The above technique may include expressing a leaf node with a low frequency in a B+tree manner based on a frequency for a leaf node, and adding a bitmap value to a leaf node with a high frequency in a B+tree manner. . In addition, the above technique: When the Distinct value exceeds a predetermined number, or for a partition where the number of occurrences of DML exceeds a predetermined number, the index is expressed in a B+tree manner, and the Distinct value is less than a predetermined number or DML For partitions with less than a predetermined number of times, a technique of expressing an index by adding a bitmap value to the B+tree method may be included.

According to an embodiment of the present disclosure, it is possible to minimize the size of the index as well as increase the query processing performance of the DBMS. According to an embodiment of the present disclosure, not only the query processing time in the DBMS can be reduced, but also an optimized efficient indexing technique suitable for redemption conditions in the DB system can be provided.

1 shows a schematic diagram of a database management device 120 and a client 110 according to an embodiment of the present disclosure.

As shown in FIG. 1, the database system may include a client 110 and a database management device 120. The database management device in the present specification may be used interchangeably with a database server.

As shown in FIG. 1, the client 110 may refer to node(s) in a database system having a mechanism for communicating over a network. For example, the client 110 can include a PC, laptop computer, workstation, terminal, and/or any electronic device with network connectivity. Also, the client 110 may include any server implemented by at least one of an agent, an application programming interface (API), and a plug-in. For example, the client 110 in FIG. 1 may be associated with a user using the database management device 120. In this example, the client 110 may issue various types of queries, including DML and DDL (Data Definition Language), to the database management device 120.

The database management apparatus 120 may include any type of computer system or computer device, such as, for example, a microprocessor, mainframe computer, digital single processor, portable device, and device controller. For example, the database management device 120 according to an embodiment of the present disclosure may include a database server. The database management device 120 may include a DBMS (Database Management System) 130 and a persistent storage medium (persistent storage) (140). Although FIG. 1 shows one database management device, it will be apparent to those skilled in the art that more database management devices may be included in the scope of the present invention.

Although not illustrated in FIG. 1, the database management device 120 may include one or more memories including a buffer cache. Also, although not illustrated in FIG. 1, the database management device 120 may include one or more processors. Therefore, the DBMS 130 can be operated by the processor on the memory.

Here, the memory is a main storage device directly accessed by a processor, such as dynamic random access memory (DRAM) or static random access memory (SRAM), and stored information when the power is turned off. Can mean a volatile storage device that is instantly erased, but is not limited to these. This memory can be operated by a processor. The memory may temporarily store a data table and/or index table including data values. The data table and the index table may include data values, and in one embodiment of the present invention, the data values of the tables may be recorded from memory to a permanent storage medium. In a further aspect, the memory includes a buffer cache, and data may be stored in a data block of the buffer cache. The data can be recorded on a permanent storage medium by a background process.

The permanent storage medium 140 is, for example, a magnetic disk, an optical disk and a magneto-optical storage device, as well as a storage device based on flash memory and/or battery-backed memory, Refers to a non-volatile storage medium capable of continuously performing arbitrary data. The permanent storage medium 140 may communicate with the processor and memory of the database management device 120 through various communication means. In a further embodiment, the permanent storage medium 140 may be located outside the database management device 120 to communicate with the database management device 120. According to an embodiment of the present disclosure, the permanent storage medium 140 and the memory may be collectively referred to as a storage unit.

DBMS 130 to allow the database management device 120 to perform any form of operation of the database, such as retrieving, inserting, modifying and/or deleting necessary data, and creating an index and accessing the index. As a program, as described above, it may be implemented by a processor in the memory of the database management apparatus 120.

The client 110 and the database management device 120 or the database management devices may communicate with each other through a network (not shown). The network according to an embodiment of the present invention is a public switched telephone network (PSTN), x Digital Subscriber Line (xDSL), Rate Adaptive DSL (RADSL), Multi Rate DSL (MDSL), Very High Speed DSL (VDSL) ), Universal Asymmetric DSL (UADSL), High Bit Rate DSL (HDSL), and various wired communication systems such as a local area network (LAN).

In addition, the network proposed in this specification is CDMA (Code Division Multi Access), TDMA (Time Division Multi Access), FDMA (Frequency Division Multi Access), OFDMA (Orthogonal Frequency Division Multi Access), SC-FDMA (Single Carrier-FDMA) ) And other systems. Additionally, the network may include a database link (dblink), so that multiple database management devices can communicate with each other through this database link to fetch data from other database management devices. The techniques described herein can be used in the networks mentioned above, as well as other networks.

2 shows a block diagram of a DBMS 130 according to one embodiment of the present disclosure.

As illustrated in FIG. 2, the DBMS 130 may include a query receiving unit 201, a monitoring performing unit 203, a query processing unit 205, a communication unit 207, and a storage unit 209. The components illustrated in FIG. 2 are exemplary, and some components may be omitted or additional components may be added depending on the implementation aspect of the invention. Components in the DBMS 130 may be executed by one or more processors and stored in a memory and/or permanent storage medium 140. The above-described memory and permanent storage medium 140 may be integrated into the storage unit 209. In this case, the storage unit 209 may communicate with the processor to control data storage/management.

The query receiving unit 201 may control receiving any type of query issued from the client 110. The query receiving unit 201 may perform a specific operation on the received query. Queries in the present disclosure may include Data Manipulation Language (DML) including querying, updating, adding, changing, deleting, and inserting data. For example, such DML may include SELECT, INSERT, UPDATE, and DELETE related commands. Further, the query in the present disclosure may include a data definition language (DDL) used when defining, changing, or removing schemas, domains, tables, views, and indexes. The DDL may include commands such as CREATE, ALTER, DROP, RENAME, and TRUNCATE. As an example of DDL, a query for creating a database index structure may be included.

After the processor parses, transforms, and optimizes the query through the DBMS 130, the query can be executed in the form of an optimized query statement. Additionally, when the query receiving unit 201 receives a query, a plurality of (candidate) execution algorithms for it may be automatically determined, or a plurality of (candidate) execution algorithms based on a hint received from the client May be decided. As an example related to data inquiry, an execution algorithm on whether to perform data inquiry through an index or full table scan may be determined.

In one aspect of the present invention, queries related to the creation of a database index structure include, for example, CREATE INDEX, CREATE INDEX WITH DROP_EXISTING, ALTER INDEX REBUILD, ALTER TABLE ADD CONSTRAINT (PRIMARY KEY or UNIQUE), ALTER TABLE DROP CONSTRAINT (PRIMARY KEY) Or UNIQUE), and DROP INDEX MOVE TO, and the like.

The monitoring execution unit 203 may perform a monitoring operation that can be a basis for creating a database index structure. The monitoring operation in the present specification includes the number of times/frequency information accessed for a specific key value, the number/frequency information accessed for specific data, distinct value information for a specific partition, and the number of DML occurrences for a specific partition in order to build an index. It may mean a process of acquiring at least one of /frequency information and last access point information of data included in a specific partition. The count/frequency information may mean a counting value or a count value per hour. The time point information may mean actual time information or time information (for example, a TSN (Tibero Sequence Number)) that the database management device 120 manages itself.

The monitoring execution unit 203 may generate monitoring result information according to monitoring execution. As a result of monitoring, a plurality of sub-index structures included in the database index structure may include a specific sub-index structure (eg, a sub-sub index structure) that is different from the indexing method of the first type or the indexing method of the first type. It may include an indication of which indexing method to use among the indexing methods. In one embodiment of the present disclosure, a particular type of indexing scheme may include any indexing scheme. For example, the first type of indexing scheme may include a bitmap indexing scheme. The second type of indexing scheme may include a B+tree indexing scheme. In addition, the monitoring result information may indicate which indexing method to use in the ROWID unit and/or the partition unit in which the database table is partitioned.

According to the above-described examples, for example, the monitoring result information may include an indication that a specific row of a leaf node uses a B+tree indexing scheme and another row different from a particular row uses a bitmap indexing scheme. As another example, the monitoring result information may include an indication that a specific partition of the database table uses a B+tree indexing method, and another partition different from the specific partition uses a bitmap indexing method.

According to an embodiment of the present disclosure, the monitoring performing unit 203 may perform a monitoring operation based on a predetermined monitoring algorithm. For example, according to the first monitoring algorithm, the monitoring execution unit 203 may generate monitoring result information by monitoring the number of times the column value of the base data structure referenced by the database index structure is accessed. . In this case, for example, the monitoring result information may include an indication of which indexing method to use, the first type of indexing method or the second type of indexing method on a row basis. In this case, if the number of times the column value is accessed is greater than the predetermined number of access thresholds, the monitoring result information indicates that the bitmap indexing method is used, and the number of times the column value is accessed is less than the predetermined number of access thresholds. In this case, the monitoring result information may indicate that a B+tree indexing method is used.

According to an embodiment of the present disclosure, monitoring result information generated by the monitoring performing unit 203 may be generated in a partition unit based at least in part on partition property information of a basic data structure referenced by a database index structure. have. For example, the basic data structure may include data tables indexed by the database index structure. The partition characteristic information may be determined based on at least one of the size information of the partition's Distinct value and the number of DML occurrences for the partition. For example, if the size information of the Distinct value of a partition is less than a predetermined size threshold value, or if the number of DML occurrences for the partition is less than a predetermined DML occurrence number threshold, the monitoring result information is transmitted to the partition. The bitmap indexing method is used, and when the DML occurrence count information for a partition is equal to or greater than a predetermined DML occurrence count threshold, the monitoring result information may indicate that the B+tree indexing method is used for the partition. .

According to an embodiment of the present disclosure, monitoring result information generated by the monitoring performing unit 203 may be determined based at least in part on the last access point information of data included in the partition. In this case, when the last access point information of data included in a partition is older than a predetermined threshold time point information, the monitoring result information may indicate that a bitmap indexing method is used for the partition. In addition, when the last access point information of data included in a partition is not older than a predetermined threshold time point information, the monitoring result information may indicate that a B+tree indexing method is used for the partition.

Since a different type of indexing method can be applied to each row unit and/or each partition unit by the monitoring operation of the monitoring execution unit 203, the overall indexing performance can be optimized.

For example, in the case of the existing bitmap index, if the distinct value is large, the size may be inefficiently increased. Therefore, by the technique according to an embodiment of the present disclosure, specific values occupy most of the entire data, and the remaining values are small numbers, so for the long tail data, corresponding values are accessed through bitmap indexing. The row pieces representing the data are reduced. Furthermore, by using a technique according to an embodiment of the present disclosure, unnecessary space waste can be reduced by using a B+tree indexing method for values with a low frequency. That is, by the technique according to an embodiment of the present disclosure, the index speed may be increased while reducing the size of the index structure.

As another example, when DML occurs frequently, a B+tree index is advantageous, and a bitmap index may be advantageous for select queries and the like. For example, a bitmap index is used for a partition that contains historical data, and a B+tree index is used for a partition that contains current data that is updated, inserted, etc. Response performance can be improved.

According to an embodiment of the present disclosure, monitoring result information generated by the monitoring performing unit 203 may be stored and managed in the storage unit 209. In this case, the query processing unit 205 may retrieve the monitoring result information stored in the storage unit 209 to generate a database index structure according to the monitoring result information.

The query processing unit 205 may perform an arbitrary operation on the corresponding query. The query processing unit 205 may generate one or more execution algorithms for the query received by the query receiving unit 201. The query processing unit 205 may determine an execution algorithm for executing a query, and perform an operation for processing a query according to the determined execution algorithm.

When receiving a query related to index structure definition/creation, the query processing unit 205 may generate a database index structure based on the monitoring result information of the monitoring execution unit 203. The generated database index structure may have a form having a plurality of sub-index structures hierarchically.

For example, the database index structure may include a first level sub-index structure and a second level sub-index structure that is lower than the first level. In this case, the sub-index structure of the first level may correspond to the root node, and the sub-index structure of the second level may correspond to the leaf node. In addition, the database index structure may include the sub-index structure of the first level, the first A sub-level structure of the second level, which is a lower level of the level, and a sub-index structure of the third level, which is a lower level of the second level. In this case, the sub-index structure of the first level may correspond to the root node, the sub-index structure of the second level may correspond to the branch node, and the sub-index structure of the third level may correspond to the leaf node. .

According to an embodiment of the present disclosure, one or more sub-index structures (eg, a root node and/or a branch node) of a plurality of sub-index structures may include a starting ROWID value of the sub-index structure of the sub-level and its sub-level. It may include an address value for accessing the sub-index structure of. Accordingly, the upper node can point to the lower node(s), so that traverse from the upper level to the lower level in the index structure can be made. The processor may check the condition of each node when performing traverse and perform an operation based on the condition. The condition may be whether the index number of the search target is included in the range of index numbers included in the node.

According to an embodiment of the present disclosure, one or more sub-index structures (eg, leaf nodes) of the plurality of sub-index structures may include a plurality of columns. The first column of the plurality of columns includes key values, the second column of the plurality of columns includes ROWID values corresponding to the row of the data block, and the third column of the plurality of columns monitors the Optimized index values that are set based on the result information may be included.

The "optimization index value" according to an embodiment of the present disclosure may include an indication of what type of indexing method is used. For example, it may be determined whether the corresponding column value uses a bitmap index or a B+tree index based on the optimization index value. For example, when it is determined to use the B+tree indexing method, the optimization index value may include a NULL value. In addition, when it is determined to use the bitmap indexing method, the optimization index value may include a corresponding bitmap value. Bitmap indexing may be performed according to the corresponding bitmap value. That is, the optimization index value according to an embodiment of the present disclosure, when the monitoring result information indicates that a bitmap type indexing method is used, will include the bitmap value for the corresponding row, and the monitoring result information is B+ When indicating that a tree type indexing method is used, a NULL value will be included for a corresponding row.

The fourth column of the plurality of columns according to an embodiment of the present disclosure may include end ROWID values. In this case, when the monitoring result information indicates that the indexing method of the B+ tree is to be used, the ending ROWID values may include a NULL value for the corresponding row. The ending ROWID value may mean the last ROWID value for indicating a range of ROWIDs of a corresponding sub-index structure starting with the ROWID value included in the second column. In this case, the bitmap value included in the third column is a bit indicating a relative distance between the reference point and the positions of other ROWID values using the ROWID value (that is, the starting ROWID) included in the second column as a reference point ( bit) value.

The communication unit 207 may provide a communication function with another database management device or the client 110. For example, the communication unit 207 may determine to transmit the processing result for the received query to the client 110. In addition, the communication unit 207 may control communication with other database management devices or clients 110 using any network and/or database link described above. In addition, the communication unit 207 may control receiving data storage, inquiry and index definition/creation/build, inquiry request, etc. from the client 110. In addition, the communication unit 207 may transmit data, result of query and index build, and query request information to the client 110 or internal components.

The storage unit 209 may store any data stored in connection with the task execution of the database management device 120. The storage unit 209 may be included in the DBMS 130 and/or the permanent storage medium 140. Additionally, the storage unit 209 may generate a table (eg, an index table) or the like on the database management device 120. For example, the creation of these tables may be performed by a separate component, such as a control module (not shown). Further, the storage unit 209 may process and manage requests related to storage (including updates) of data. The storage unit 209 may determine to store data, index tables, and the like. Also, the storage unit 209 may determine a storage location for data and/or index tables. For example, the storage unit 209 may determine a storage location on the data table for data. As another example, the storage unit 209 may determine a storage location on the permanent storage medium 140 for data. The storage unit 209 may store the created database index structure. In additional embodiments of the present disclosure, storage 209 may include memory and/or permanent storage media 140.

3 is a block diagram of a database management apparatus according to an embodiment of the present disclosure.

As illustrated in FIG. 3, the database management device 120 may include a processor 310 and a storage unit 320. The processor 310 may control operations performed by the DBMS 130 described in FIG. 2. The processor 310 may execute the operations described in FIG. 2 by executing the DBMS 130. For example, the processor 310 may perform a monitoring operation and a creation operation of the database index structure 330. As another example, the processor 310 may store the generated database index structure 330 in the storage unit 320. Since the operations of the processor 310 correspond to the operations of the DBMS 130 described in FIG. 2, descriptions thereof will be omitted in the description related to FIG. 3.

The storage unit 320 illustrated in FIG. 3 may correspond to the memory and/or permanent storage medium described above. The storage unit 320 may store the database index structure 330. 2, the database index structure 330 may include one or more sub-index structures 340, 350, 360a and 360b. The sub-index structures 340, 350, 360a, and 360b may correspond to the root node 340, branch node 350, and/or leaf nodes 360a and 360b. The database index structure 330 stored in the storage unit 320 shown in FIG. 3 includes only one root node, one branch node, and two leaf nodes, but this is only an example for convenience of description, Any number and any type of nodes can form the database index structure 330 without departing from the spirit of the present disclosure.

In one embodiment of the present disclosure, the root node 340 and the branch node 350 have a ROWID value of a lower-level sub-index structure lower than their own, and an address value for accessing the lower-level sub-index structure. It may include. For example, when the processor 310 traverses from the root node 340, a branch value to the branch node 350 included in the root node 340 (that is, which branch node 350 is to be traversed) Based on the value to be determined) and the address of the branch node 350 (DBA: Data Block Address), the processor 310 may determine the branch node 350 to traverse. The branch node 350 may also determine leaf nodes to traverse among the leaf nodes 360a and 360b in the same manner.

4 exemplarily illustrates a database index structure according to an embodiment of the present disclosure.

According to an embodiment of the present disclosure, an optimal indexing technique for combining a bitmap index and a B+tree index in an efficient manner may be provided. Such an indexing technique may include: expressing a leaf node with a low frequency based on a frequency for a leaf node in a B+tree manner, and adding a bitmap value to a leaf node with a high frequency in a B+tree manner. have. In addition, the indexing technique: When the Distinct value exceeds a predetermined number, or for a partition in which the number of occurrences of DML exceeds a predetermined number, the index is expressed in a B+tree manner, and the Distinct value is less than or equal to the predetermined number. For partitions in which the occurrence of DML is less than a predetermined number of times, a technique of expressing an index by adding a bitmap value to the B+tree method may be included.

As shown in FIG. 4, each leaf node 360a and 360b may have a sub index structure 400. Each sub-index structure 400 of each leaf node 360a and 360b may include at least three columns 410, 420, and 430, respectively. The first column 410 may include index key values. The index key value may include a column value in a base table, an arbitrary hash value for the column value, and/or any conversion value for the column value. The key values may have unique values within the first column 410 or may have duplicate values. As illustrated in FIG. 4, the first column 410 may have key values of 1, 1, 2, 3, 4, and 5.

The second column 420 may include ROWID values corresponding to rows of the data block. ROWID may correspond to a location where actual data is stored. Through this ROWID, since it is possible to find a location where actual data is stored, efficient data search is possible compared to a full scan of the table. According to an embodiment of the present disclosure, although not illustrated in FIG. 4, a fourth column may be included in the sub index structure 400. The fourth column may include end ROWID values. In this case, when the monitoring result information indicates that the indexing method of the B+ tree is to be used, the ending ROWID values may include a NULL value for a corresponding row or a corresponding key value. The ending ROWID value may refer to the last ROWID value for indicating the range of ROWIDs of the corresponding sub-index structure 400 starting with the ROWID value included in the second column 420. In this case, the bitmap value included in the third column 430 is a relative distance between the reference point and the positions of other ROWID values using the ROWID value (that is, the starting ROWID) included in the second column 420 as a reference point. It may mean a bit value indicating.

As described above, the third column 430 may include optimized index values that are set based on monitoring result information. That is, the values included in the third column 430 may have a NULL value when the monitoring result information indicates that the B+tree index is used for a specific row or a specific key value. The values included in the third column 430 may have a bitmap value (that is, a bit value) when the monitoring result information indicates that a bitmap index is used for a specific row or a specific key value. have.

For example, if the number of times of access to the column value or the number of times of access to the key value is greater than a predetermined number of access thresholds (for example, once per minute or a total of 100 times, etc.), the bitmap indexing method is determined. In addition, when the number of times of access to the column value or the number of times of access to the key value is equal to or less than the predetermined access threshold number, it may be determined to use the B+tree indexing method.

As illustrated in FIG. 4, data structures having key values, ROWID and NULL values for key values 1, 3, and 4, which are low-frequency data accesses, have key values 2, 5, which are high-frequency data accesses. For can have a data structure having a key value, ROWID and bitmap value. In the example shown in FIG. 4, it is shown that it is possible to determine whether to use a bitmap index or a B+tree index as a key value unit. However, as another example, whether to have a bitmap value or a NULL value in ROWID units is monitored. It can also be set by the result information.

In a further embodiment of the present disclosure, mapping relationships between key values or rows determined by key values or rows and key values or rows may be stored in the meta table as metadata. As the meta table is formed, a more efficient index build can be made by checking the mapping relationship stored in the meta table without separately performing a monitoring process each time an index structure is generated.

As described above, a sub-index structure (eg, a data structure of a leaf node) according to an embodiment of the present disclosure can provide a global index that can use a bitmap index structure and a B+tree index structure as one index. have. That is, the indexing method according to the present disclosure reduces unnecessary space for one index structure because a bitmap index is used for data having a high access frequency and a B+tree index is used for data having a low access frequency. As a result, not only can the size of the index be minimized, but the speed of the index can be improved.

5 exemplarily illustrates different database index structures in units of partitions according to an embodiment of the present disclosure.

As illustrated in FIG. 5, partitions 1 to 10 (510a, 520a, 530a, and 540a) may have different index structures 510b, 520b, 530b, and 540b in units of partitions, respectively. According to the example in FIG. 5, partitions 1, 2, and 9 (510a, 520a, 530a) may have B+tree indexes 510b, 520b, and 530b as local indexes. Partition 10 (540b) may have a bitmap index (540b) as a local index.

For example, the size information of the partition's Distinct value is smaller than a predetermined size threshold (for example, 2, 5, 10, 100, etc.) or the DML occurrence number information for the partition is a predetermined DML occurrence count threshold ( For example, if it is smaller than once per hour or 10 times in total, it may be determined that the bitmap indexing scheme is used for the partition. In one example, the predetermined size threshold may be preset by the user. As another example, the predetermined size threshold may be variably and dynamically determined based on monitoring result information by the monitoring performing unit 203. Further, when the DML occurrence count information for a specific partition is equal to or greater than a predetermined DML occurrence count threshold, it may be determined that the B+tree indexing scheme is used for the partition.

In addition, when the last access point information of data included in a specific partition is older than predetermined threshold time information (eg, 24 hours, 7 days, 30 days, etc.), it may be determined that a bitmap indexing method is used for the partition. . In addition, when the last access point information of the data included in the partition is not older than the predetermined threshold time point information, it may be determined that the B+tree indexing method is used for the partition.

Since the sub-index structure of each partition is the same as the sub-index structure 400 described with reference to FIG. 4, the description will be omitted in FIG. 5.

In a further embodiment of the present disclosure, the mapping relationship between the partitions 510a, 520a, 530a, 540a and the index structures 510b, 520b, 530b, 540b determined in units of partitions may be stored in the meta table as metadata. have. As the meta table is formed, a more efficient index build can be made by checking the mapping relationship stored in the meta table without separately performing a monitoring process each time an index structure is generated.

According to a partitioning indexing scheme according to an embodiment of the present disclosure, a local index that can use a bitmap index structure or a B+tree index structure for each partition may be provided according to partition characteristics. In other words, the bitmap index is used for partitions with little or no DML in the partition, and the B+tree index is used for partitions with frequent DML, enabling efficient space management and query performance. This can be improved.

6 exemplarily shows a flowchart for performing efficient indexing, according to one embodiment of the present disclosure. The steps illustrated in FIG. 6 may be performed, for example, by the database management device 120. In addition, the steps shown in FIG. 6 may be performed, for example, by one or more processors 310. The steps shown in FIG. 6 are exemplary and additional steps may be present or some of the steps shown may be omitted.

As shown in FIG. 6, the database management device 120 may receive a query requesting an index build issued from a user (610). For example, a query requesting an index build may include an indication that an index type data structure is to be generated to facilitate searching for the generated data table structure.

In response to requesting an index build, the database management device 120 may perform a monitoring operation for the index build based on a predetermined monitoring algorithm (630). As a result of the monitoring operation, monitoring result information may be generated. Any method of database monitoring may be used to perform the monitoring operation. The monitoring operation in the present specification includes the number of times/frequency information accessed for a specific key value, the number/frequency information accessed for specific data, distinct value information for a specific partition, and the number of DML occurrences for a specific partition in order to build an index. It may mean any type of process of acquiring at least one of /frequency information and information on the last access time of data included in a specific partition. For example, the count/frequency information may mean a counting value or a count value per hour, but these are only examples, and if the information is in a comparable form, it may be included in monitoring result information.

The database management device 120 may create a database index structure based on the monitoring result information generated by the monitoring operation (630). The database index structure may be variably set according to an indication included in monitoring result information. In addition, the database management apparatus 120 may connect the generated database index structure and the underlying data table to each other. Since the detailed description of the database index structure has been previously described with reference to FIGS. 2 to 5, the description of FIG. 6 will be omitted.

The database management apparatus 120 may store the generated database index structure in a storage unit of any type (650). The storage unit may include temporary/temporary storage media and/or permanent storage media. For example, the database management device 120 may store the created database index structure in a buffer cache. In this case, the database index structure stored in the buffer cache by a background process at a predetermined cycle or by user setting may be recorded as a permanent storage medium. In addition, the generated database index structure may be stored in a separate storage server, and the separate storage server may collect and store arbitrary types of data in group units in a permanent storage medium.

7 shows various exemplary logical blocks, configurations, modules, means and logics, and algorithm steps in accordance with one embodiment of the present disclosure.

Those skilled in the art further include various exemplary logical blocks, configurations, modules, circuits, means, logics, and algorithm steps described in connection with the embodiments disclosed herein, electronic hardware, computer software, or a combination of both. It should be recognized that can be implemented as To clearly illustrate the interchangeability of hardware and software, various illustrative components, blocks, configurations, means, logics, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented in hardware or as software depends on the specific application and design limitations imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The means, logic, and module illustrated in FIG. 7 may correspond to the steps described in FIG. 6, respectively.

As shown in FIG. 7, the database management apparatus 120 includes means 710 for receiving a query requesting an index build, and means 730 for performing a monitoring operation for an index build based on a monitoring algorithm. , Means 750 for creating a database index structure based on the monitoring result information and means 770 for storing the created database index structure.

In addition, the database management apparatus 120 is based on logic 810 for receiving a query requesting an index build, logic 830 for performing a monitoring operation for an index build based on a monitoring algorithm, and monitoring result information By doing so, it may include logic 850 for creating a database index structure and logic 870 for storing the generated database index structure.

In addition, the database management device 120 is based on a module 910 for receiving a query requesting an index build, a module 930 for performing a monitoring operation for an index build based on a monitoring algorithm, and monitoring result information To include a module 950 for creating a database index structure and a module 970 for storing the created database index structure.

8 shows a simplified and general schematic diagram of an exemplary computing environment in which embodiments of the present disclosure can be implemented.

Although the present disclosure has been described above in general with respect to computer-executable instructions or logic that may be executed on one or more database management devices, those skilled in the art may implement the present disclosure in combination with other program modules and/or as a combination of hardware and software. You know it can be.

Generally, program modules include routines, procedures, programs, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In addition, those of ordinary skill in the art may find that the methods and operations of the present invention include single-processor or multiprocessor computer systems, minicomputers, mainframe computers as well as personal computers, handheld computing devices, microprocessor-based or programmable consumer electronics, and the like. It will be appreciated that each may be implemented with other computer system configurations, including one or more associated devices (eg, capable of operating in conjunction with database management device 120).

The described embodiments of the invention may also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

Computers (eg, database management device 120) typically include a variety of computer readable media. Any computer-accessible medium can be any computer-readable medium, such computer-readable media being volatile and non-volatile media, transitory and non-transitory media, removable and non- Includes removable media. By way of example, and not limitation, computer readable media may include computer readable storage media and computer readable transmission media. Computer-readable storage media are volatile and non-volatile media, temporary and non-transitory media, removable and non-removable, implemented in any method or technology for storing information such as computer readable instructions, data structures, program modules or other data Includes media. Computer-readable storage media may include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital video disk (DVD) or other optical disk storage device, magnetic cassette, magnetic tape, magnetic disk storage device or other magnetic storage Devices, or any other medium that can be accessed by a computer and used to store desired information.

Computer readable transmission media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and Includes all information delivery media. The term modulated data signal means a signal in which one or more of the characteristics of the signal are set or changed to encode information in the signal. By way of example, and not limitation, computer readable transmission media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media.

An exemplary environment 1100 is shown that implements various aspects of the invention, including a computer 1102, which includes a processing device (or processor) 1104, system memory 1106, and system bus ( 1108). System bus 1108 connects system components, including, but not limited to, system memory 1106 to processing device 1104. The processing device 1104 can be any of a variety of commercial processors. Dual processor and other multiprocessor architectures may also be used as the processing unit 1104.

The system bus 1108 can be any of several types of bus structures that can be further interconnected to a memory bus, peripheral bus, and local bus using any of a variety of commercial bus architectures. System memory 1106 includes read-only memory (ROM) 1110 and random access memory (RAM) 1112. A basic input/output system (BIOS) is stored in a non-volatile memory 1110 such as ROM, EPROM, EEPROM, etc. This BIOS is a basic to help transfer information between components in the computer 1102 at the same time as during startup. Contains routines. The RAM 1112 may also include high-speed RAM, such as static RAM for caching data.

Computer 1102 is also an internal hard disk drive (HDD) 1114 (eg, EIDE, SATA) (this internal hard disk drive 1114 can also be configured for external use within a suitable chassis (not shown)) Magnetic floppy disk drive (FDD) 1116 (e.g., for reading from or writing to removable diskette 1118), and optical disk drive 1120 (e.g., CD-ROM) Disc 1122 for reading or reading from or writing to other high-capacity optical media such as DVD). The hard disk drive 1114, the magnetic disk drive 1116, and the optical disk drive 1120 are the system bus 1108 by the hard disk drive interface 1124, the magnetic disk drive interface 1126, and the optical drive interface 1128, respectively. ). The interface 1124 for implementing an external drive includes at least one of USB (Universal Serial Bus) and IEEE 1394 interface technology, or both.

These drives and their associated computer-readable media provide non-volatile storage of data, data structures, computer-executable instructions, and the like. In the case of computer 1102, drives and media correspond to storing any data in a suitable digital format. Although the above description of computer readable media refers to HDDs, removable magnetic disks, and removable optical media such as CDs or DVDs, those of ordinary skill in the art can use zip drives, magnetic cassettes, flash memory cards, cartridges, etc. It will be appreciated that other types of media readable by a computer, etc., may also be used in the exemplary operating environment and that any such media may include computer-executable instructions for performing the methods of the present invention.

A number of program modules may be stored in the drive and RAM 1112, including the operating system 1130, one or more application programs 1132, other program modules 1134, and program data 1136. All or a portion of the operating system, applications, modules and/or data may also be cached in RAM 1112. It will be appreciated that the present invention can be implemented in various commercially available operating systems or combinations of operating systems.

The user may input commands and information to the computer 1102 through one or more wired/wireless input devices, for example, pointing devices such as a keyboard 1138 and a mouse 1140. Other input devices (not shown) may include a microphone, IR remote control, joystick, game pad, stylus pen, touch screen, etc. These and other input devices are often connected to the processing unit 1104 through an input device interface 1142 connected to the system bus 1108, but the parallel port, IEEE 1394 serial port, game port, USB port, IR interface, And other interfaces.

The monitor 1144 or other type of display device is also connected to the system bus 1108 through an interface such as a video adapter 1146. In addition to the monitor 1144, the computer generally includes other peripheral output devices (not shown), such as speakers, printers, and the like.

The computer 1102 can operate in a networked environment using logical connections to one or more remote computers, such as remote computer(s) 1148 via wired and/or wireless communication. The remote computer(s) 1148 may be a workstation, server computer, router, personal computer, portable computer, microprocessor-based entertainment device, peer device, or other conventional network node, generally for computer 1102. It includes many or all of the described components, but for simplicity, only the memory storage device 1150 is shown. The illustrated logical connections include wired/wireless connections to a local area network (LAN) 1152 and/or a larger network, such as a wide area network (WAN) 1154. Such LAN and WAN networking environments are common in offices and companies, and facilitate enterprise-wide computer networks such as intranets, all of which can be connected to computer networks around the world, such as the Internet.

When used in a LAN networking environment, the computer 1102 is connected to the local network 1152 via a wired and/or wireless communication network interface or adapter 1156. The adapter 1156 may facilitate wired or wireless communication to the LAN 1152, which also includes a wireless access point installed therein to communicate with the wireless adapter 1156. When used in a WAN networking environment, the computer 1102 may include a modem 1158, connect to a communication server on the WAN 1154, or otherwise establish communication over the WAN 1154, such as through the Internet. Have a means The modem 1158, which may be an internal or external and wired or wireless device, is connected to the system bus 1108 through a serial port interface 1142. In a networked environment, program modules described for the computer 1102 or portions thereof may be stored in the remote memory/storage device 1150. It will be appreciated that the illustrated network connection is exemplary and other means of establishing a communication link between computers can be used.

The computer 1102 is associated with any wireless device or entity that is deployed and operates in wireless communication, such as a printer, scanner, desktop and/or portable computer, a portable data assistant (PDA), communication satellite, or wireless detectable tag. It operates to communicate with any equipment or place and telephone. This includes at least Wi-Fi and Bluetooth wireless technology. Accordingly, the communication may be a predefined structure as in a conventional network or simply ad hoc communication between at least two devices.

Wi-Fi (Wireless Fidelity) enables a connection to the Internet or the like without a wired connection. Wi-Fi is a wireless technology such as a cell phone that allows a device, for example, a computer to send and receive data indoors and outdoors, ie anywhere within the base station's coverage area. Wi-Fi networks use a wireless technology called IEEE 802.11 (a,b,g, etc.) to provide a secure, reliable and high-speed wireless connection. Wi-Fi can be used to connect computers to each other, to the Internet, and to a wired network (using IEEE 802.3 or Ethernet). Wi-Fi networks can operate in unlicensed 2.4 and 5 GHz radio bands, for example, at 11 Mbps (802.11a) or 54 Mbps (802.11b) data rates, or in products that include both bands (dual band). have.

A person of ordinary skill in the art of the present invention can provide a variety of exemplary logical blocks, modules, processors, means, circuits and algorithm steps described in connection with the embodiments disclosed herein, electronic hardware, (convenience For this, it will be understood that it may be implemented by various forms of program or design code (referred to herein as “software”) or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art of the present invention may implement the functions described in various ways for each specific application, but such implementation decisions should not be interpreted as being outside the scope of the present invention.

Various embodiments presented herein can be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term “manufactured article” includes a computer program, carrier, or media accessible from any computer-readable device. For example, computer-readable media include magnetic storage devices (eg, hard disks, floppy disks, magnetic strips, etc.), optical disks (eg, CDs, DVDs, etc.), smart cards, and flash memory Devices (eg, EEPROMs, cards, sticks, key drives, etc.), but are not limited to these. Also, various storage media presented herein include one or more devices and/or other machine-readable media for storing information. The term “machine-readable medium” includes, but is not limited to, wireless channels and various other media capable of storing, retaining, and/or transferring command(s) and/or data.

It is understood that the specific order or hierarchy of steps in the processes presented is an example of exemplary approaches. Based on design priorities, it is understood that within the scope of the present invention, a specific order or hierarchy of steps in the processes may be rearranged. The accompanying method claims provide elements of the various steps in a sample order, but are not meant to be limited to the specific order or hierarchy presented.

Claims (14)

A computer program stored on a computer-readable storage medium including encoded instructions, wherein the computer program, when executed by one or more processors, causes the one or more processors to improve data retrieval performance. And the operation is:
Generating a database index structure for pointing a data storage location based on monitoring result information according to a monitoring algorithm in a database management system (DBMS);
It includes,
The database index structure includes at least partially a sub-index structure of a first level and a sub-index structure of a second level lower than the first level,
The sub-index structure of the second level includes a plurality of columns,
The first column of the plurality of columns of the second-level sub-index structure includes key values,
The second column of the plurality of columns of the second-level sub-index structure includes ROWID values corresponding to a row of a data block, and
The third column among the plurality of columns of the second-level sub-index structure is determined based on at least one of monitoring result information according to a monitoring algorithm generated in a row unit or monitoring result information according to a monitoring algorithm generated in a partition unit. Includes optimized index values,
The optimization index value included in the third column,
When the monitoring result information indicates that a second type of indexing method is used, a NULL value is included,
Monitoring result information according to the monitoring algorithm generated in the partition unit,
It is generated on a partition basis based at least in part on partition property information of a basic data structure referenced by the database index structure.
A computer program stored on a computer-readable storage medium.
According to claim 1,
Optimization index values included in the third column,
The second level sub-index structure includes an indication of which indexing method to use, which is a first type of indexing method or a second type of indexing method different from the first type of indexing method,
A computer program stored on a computer-readable storage medium.
According to claim 1,
The monitoring result information,
The second level sub-index structure includes an indication of which indexing method to use, which is a first type of indexing method or a second type of indexing method different from the first type of indexing method,
A computer program stored on a computer-readable storage medium.
The method of claim 3,
The optimization index value included in the third column,
When the monitoring result information indicates that the first type of indexing method is to be used, including a bitmap value,
A computer program stored on a computer-readable storage medium.
The method of claim 4,
When a fourth column among a plurality of columns of the second-level sub-index structure includes end ROWID values, and the end ROWID value indicates that the monitoring result information uses the second type of indexing, Containing a NULL value,
A computer program stored on a computer-readable storage medium.
The method of claim 4,
The bitmap value is
A bit value indicating a relative distance between the reference point and the positions of other ROWID values in the sub-index structure of the second level using the ROWID value as a reference point,
A computer program stored on a computer-readable storage medium.
The method of claim 6,
The sub-index structure of the first level includes at least one of a root node and a branch node,
The second-level sub-index structure includes leaf nodes, and
The sub-index structure of the first level includes a starting ROWID value of the sub-level sub-index structure and an address value for accessing the sub-level sub-index structure,
A computer program stored on a computer-readable storage medium.
The method of claim 7,
Monitoring result information according to the monitoring algorithm,
It is generated based at least in part on the number of times the column value of the base data structure referenced by the database index structure is accessed, and the first type of indexing method or the second in a row unit or a key value unit. Including an indication of which of the types of indexing methods to use,
A computer program stored on a computer-readable storage medium.
The method of claim 8,
When the number of times of access to the column value or the number of times of access to the key value is greater than the predetermined number of access thresholds, the monitoring result information indicates that the indexing method of the first type is used,
When the number of times information accessed by the column value or the number of times of access to the key value is equal to or less than a predetermined access threshold number value, the monitoring result information indicates that the indexing method of the second type is used,
A computer program stored on a computer-readable storage medium.
According to claim 1,
The partition characteristic information of the basic data structure,
Determined based on at least one of the size information of the partition's Distinct value and the number of occurrences of DML (Data Manipulation Language) for the partition,
A computer program stored on a computer-readable storage medium.
The method of claim 10,
If the size information of the Distinct value of the partition is smaller than a predetermined size threshold or the DML occurrence count information for the partition is smaller than a predetermined DML occurrence count threshold, the monitoring result information is first for the partition. Indicates to use the type of indexing method, and
When the DML occurrence count information for the partition is equal to or greater than a predetermined DML occurrence count threshold, the monitoring result information indicates that a second type of indexing method is used for the partition,
A computer program stored on a computer-readable storage medium.
According to claim 1,
Monitoring result information according to the monitoring algorithm,
It is determined based at least in part on the last access point information of the data included in the partition,
If the last access point information of the data included in the partition is older than a predetermined threshold time point information, the monitoring result information indicates that the indexing method of the first type is used for the partition, and
When the last access point information of the data included in the partition is not older than the predetermined critical point time information, the monitoring result information indicates that a second type of indexing method is used for the partition,
A computer program stored on a computer-readable storage medium.
As a method performed in a database management system (DBMS),
Generating a database index structure for pointing the data storage location, based on the monitoring result information according to the monitoring algorithm in the database management system;
It includes,
The database index structure includes at least partially a sub-index structure of a first level and a sub-index structure of a second level lower than the first level,
The sub-index structure of the second level includes a plurality of columns,
The first column of the plurality of columns of the second-level sub-index structure includes key values,
The second column of the plurality of columns of the second-level sub-index structure includes ROWID values corresponding to the row of the data block, and
The third column among the plurality of columns of the second-level sub-index structure is determined based on at least one of monitoring result information according to a monitoring algorithm generated in a row unit or monitoring result information according to a monitoring algorithm generated in a partition unit. Includes optimized index values,
The optimization index value included in the third column,
When the monitoring result information indicates that a second type of indexing method is used, a NULL value is included,
Monitoring result information according to the monitoring algorithm generated in the partition unit,
Is generated on a partition basis based at least in part on partition characteristic information of a basic data structure referenced by the database index structure,
Way.
As a database management device,
A processor generating a database index structure for pointing the data storage location based on the monitoring result information according to the monitoring algorithm in the database management system;
A storage unit for storing the created database index structure;
It includes,
The database index structure includes at least partially a sub-index structure of a first level and a sub-index structure of a second level lower than the first level,
The sub-index structure of the second level includes a plurality of columns,
The first column of the plurality of columns of the second-level sub-index structure includes key values,
The second column of the plurality of columns of the second-level sub-index structure includes ROWID values corresponding to the row of the data block, and
The third column among the plurality of columns of the second-level sub-index structure is determined based on at least one of monitoring result information according to a monitoring algorithm generated in a row unit or monitoring result information according to a monitoring algorithm generated in a partition unit. Includes optimized index values,
The optimization index value included in the third column,
When the monitoring result information indicates that a second type of indexing method is used, a NULL value is included,
Monitoring result information according to the monitoring algorithm generated in the partition unit,
Is generated in a partition unit based at least in part on partition characteristic information of a basic data structure referenced by the database index structure,
Database management device

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