CN108073595B - A method and device for realizing data update and snapshot in OLAP database - Google Patents

Abstract

The invention discloses a method and a device for realizing data update in an OLAP database. The method includes: adding a row identification column and a timestamp column in a data table, the row identification column is used to record the row identification of each row in the data table, and the timestamp The column is used to record the modification time of each row in the data table; when a modification instruction is received, the row to be modified is determined in the data table; the row to be modified is modified according to the modification instruction and the current modification time is written in the timestamp column of the row to be modified , generate the first new row; insert the first new row into the data table; when receiving the read data command, obtain at least one result row in the data table according to the read data command, and fetch at least one result row The row with the latest modification time corresponding to each row identifier forms a result table, and the part of the result table that removes the row identifier column and the timestamp column is returned to the user. The invention also discloses a method and a device for realizing data snapshot in the OLAP database.

Description

A method and device for realizing data update and snapshot in OLAP database

technical field

The invention relates to the field of databases, in particular to a method and device for implementing data update and snapshot in an OLAP database.

Background technique

In traditional software development, stand-alone databases (such as Oracle databases, SQL Server databases, etc.) play an extremely critical role in data storage and data computing, but traditional stand-alone databases cannot achieve horizontal expansion in storage and computing, that is, they cannot Adding hardware means to store and calculate more data, so it is stretched when dealing with massive data. Therefore, distributed relational data warehouses have emerged. OLAP (Online Analytical Processing) database is a mature solution for distributed relational data warehouses, but OLAP databases are characterized by read optimization, not It is good at modification, that is, it only supports data insertion and reading, but does not support data modification and update. In many scenarios, users want to be able to modify a single row or multiple rows of data in a table in an OLAP database, just like a traditional database.

In addition, there is such a requirement in many business scenarios. Users want to get the status of a table in the database at a previous point in time, that is, a snapshot. The purpose may be to restore the data of the table to that point in time, or it may be In order to understand the information of the previous version or to do some version comparison, however, there is currently no function of obtaining snapshots in the OLAP database.

SUMMARY OF THE INVENTION

In view of the above-mentioned problems, the present invention is proposed in order to provide a method and device for realizing data update and snapshot in OLAP database that overcomes the above-mentioned problems or at least partially solves the above-mentioned problems. The technical scheme of the present invention is as follows:

A method for implementing data update in an OLAP database, the method comprising:

A row identification column and a timestamp column are added to the data table, the row identification column is used to record the row identification of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table;

When receiving the modification instruction, determine the row to be modified in the data table;

Modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first new row;

inserting the first new row into the data table;

When a read data command is received, at least one result row is obtained in the data table according to the read data command, and a row with the latest modification time corresponding to each row identifier is taken from the at least one result row to form a composition A result table, returning the part of the result table with the row ID column and the timestamp column removed to the user.

Correspondingly, the method further includes:

When an addition instruction is received, a second newly added row is generated according to the added instruction, the corresponding row identifier is written in the row identifier column of the second newly added row, and the timestamp column of the second newly added row is written in the row identifier column of the second added row. Write the current modification time;

Insert the second new row into the data table.

Correspondingly, determining the row to be modified in the data table includes:

Obtain at least one row to be selected for modification in the data table according to the modification instruction, and select a row with the latest modification time corresponding to each row identifier in the at least one row to be selected for modification as the row to be modified.

A method for implementing data snapshots in an OLAP database, the method comprising:

A row identification column and a timestamp column are added to the data table, the row identification column is used to record the row identification of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table;

receiving a read snapshot instruction, where the read snapshot instruction includes a time point;

Searching in the data table for a row whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row;

In the snapshot candidate rows, a row with the latest modification time corresponding to each row identifier is taken to form a snapshot table, and the part of the snapshot table excluding the row identifier column and the timestamp column is returned to the user.

Correspondingly, the method further includes:

When a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table, a prompt that no snapshot is found is generated.

A device for realizing data update in an OLAP database, the device comprising:

The first adding unit is used to add a row identifier column and a timestamp column in the data table, the row identifier column is used to record the row identifier of each row in the data table, and the timestamp column is used to record the data table The modification time of each row in ;

a determining unit for determining the row to be modified in the data table when the modification instruction is received;

a modification unit, configured to modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first newly added row;

a first inserting unit for inserting the first newly added row into the data table;

The reading unit is configured to obtain at least one result row in the data table according to the read data instruction when receiving the read data instruction, and fetch the at least one result row corresponding to each row identifier with The row with the latest modification time constitutes a result table, and the part of the result table excluding the row ID column and the timestamp column is returned to the user.

Correspondingly, the device further includes:

The second adding unit is configured to generate a second newly added row according to the adding instruction when receiving the adding instruction, write the corresponding row identifier in the row identifier column of the second newly added row, and write the corresponding row identifier in the row identifier column of the second newly added row. The timestamp column of the new row is written to the current modification time;

The second inserting unit is used for inserting the second newly added row into the data table.

Correspondingly, the determining unit is specifically used for:

Obtain at least one row to be selected for modification in the data table according to the modification instruction, and select a row with the latest modification time corresponding to each row identifier in the at least one row to be selected for modification as the row to be modified.

A device for implementing data snapshots in an OLAP database, the device comprising:

an adding unit for adding a row ID column and a timestamp column in the data table, the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record each row in the data table modification time;

a receiving unit, configured to receive a read snapshot instruction, where the read snapshot instruction includes a time point;

a search unit, configured to search in the data table for a row whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row;

A snapshot unit, configured to select a row with the latest modification time corresponding to each row identifier in the snapshot candidate row to form a snapshot table, and remove the row identifier column and the timestamp column from the snapshot table. returned to the user.

Correspondingly, the device further includes:

The prompt unit is configured to generate a prompt that no snapshot is found when a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table.

By the above-mentioned technical scheme, the method and device for realizing data update and snapshot in the OLAP database provided by the present invention, by recording the row identifier and modification time of each row in the data table, when the data needs to be modified, the row to be modified is modified, and Keep the row ID of the row to be modified unchanged and record the latest modification time in the row to be modified. When the user reads the data, return the data with the latest modification time for each row ID and return it to the user, for the user to read What is obtained is the modified data, which has the same effect as the data has actually been modified, which satisfies the needs of realizing data update in the OLAP database. In addition, when the user reads the snapshot, the data whose row identifier is less than or equal to the snapshot time point and has the latest modification time is returned to the user, thereby realizing the function of reading the snapshot in the OLAP database.

The above description is only an overview of the technical solutions of the present invention, in order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand , the following specific embodiments of the present invention are given.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating preferred embodiments only and are not to be considered limiting of the invention. Also, the same components are denoted by the same reference numerals throughout the drawings. In the attached image:

1 shows a flowchart of a method embodiment for implementing data update in an OLAP database provided in an embodiment of the present invention;

Fig. 2 shows the schematic diagram of the data table in the embodiment of the present invention;

3 shows a schematic diagram of modifying a data table in an embodiment of the present invention;

FIG. 4 shows another schematic diagram of modifying the data table in an embodiment of the present invention;

5 shows a schematic diagram of adding a data table in an embodiment of the present invention;

6 shows a schematic diagram of reading a data table in an embodiment of the present invention;

FIG. 7 shows a flowchart of a method embodiment for implementing a data snapshot in an OLAP database provided in an embodiment of the present invention;

FIG. 8 shows a schematic diagram of reading a data snapshot in an embodiment of the present invention;

9 shows a schematic diagram of an embodiment of an apparatus for implementing data update in an OLAP database provided in an embodiment of the present invention;

FIG. 10 shows a schematic diagram of an embodiment of an apparatus for implementing a data snapshot in an OLAP database according to an embodiment of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

The main purpose of the present invention is to allow users to perform single-row or multiple-row modification and update operations on table data on an OLAP database based on Hadoop (a distributed system infrastructure) just like operating a traditional stand-alone database, so as to overcome the OLAP database. The biggest defect; in addition, the purpose of the present invention is to enable users to obtain snapshots of any table at any point in time in a very simple manner when using the OLAP database.

Referring to FIG. 1 , a method embodiment for implementing data update in an OLAP database provided in an embodiment of the present invention is shown, which may include the following steps:

Step 101: Add a row ID column and a timestamp column to the data table, where the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table.

First, add two hidden columns to the data table: the row ID column and the timestamp column. The hidden column is transparent to the user, and the user does not know the existence of these two columns. Among them, the row ID column is used for Record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table.

Referring to Figure 2, it is an example of adding a row ID column and a timestamp column in a data table. The left table in Figure 2 is the original data table, and the row ID column and time can be added when the user creates the original data table. Stamp the column to generate the updated data table shown in the right table in Figure 2. It can be seen that different data rows in the original data table have different row IDs, and the timestamp column records the modification time of each row.

Step 102: When the modification instruction is received, determine the row to be modified in the data table.

In some possible implementations of the present invention, the specific implementation of determining the row to be modified in the data table may include:

Obtain at least one row to be modified in the data table according to the modification instruction, and select the row with the latest modification time corresponding to each row identifier in the at least one row to be modified as the row to be modified.

Step 103: Modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first newly added row.

Step 104: Insert the first newly added row into the data table.

When the user needs to modify a certain row or some rows in the data table, a modification instruction can be sent to the database, and the modification instruction includes the conditions for determining the row to be modified. In this embodiment, the first newly added row represents a data row after the row to be modified is modified, and there may be one or more rows to be modified, and there may also be one or more first newly added rows.

Referring to Fig. 3, for example, it is necessary to modify the "technical department" in the data table shown in the right table of Fig. 2 to "software department", then first, according to the modification instruction, look up the data table shown in the right table of Fig. 2 to obtain The row of "Technical Department" in the department column is used as the row to be selected for modification, that is, the rows with row identifiers "01" and "02" are determined as rows to be selected for modification, and at this time, the row identifiers in the data table are "01" and "02" ” has only one row of data, then the two rows of data are the rows with the latest modification time corresponding to the two row IDs, and are determined as the rows to be modified. After the rows to be modified are modified according to the modification instructions, the row IDs Keep it unchanged, write the current modification time in the timestamp column, insert it into the data table, and generate the data table shown in Figure 3, so that there will be multiple rows with different modification times in the same row ID in the data table.

Referring to Fig. 4, for another example, on the basis of the above modification (that is, on the basis of the data table shown in Fig. 3), the age of "Zhang San" is modified to "31", then first according to the modification instruction shown in Fig. 3 Find the row whose name is listed as "Zhang San" in the data table of , that is, determine the row with the row ID "01" as the row to be selected for modification, and at this time, the row with the row ID "01" has two rows of data, you need to From the two rows to be modified, select the row with the latest modification time corresponding to the row ID as the row to be modified (that is, the penultimate row in the data table shown in FIG. 3 is the row to be modified this time), After the modified row is modified according to the modification instruction, the row ID remains unchanged, the current modification time is written in the timestamp column, and the data table is inserted to generate the data table shown in FIG. 4 .

In addition, in some possible implementation manners of the present invention, data rows may also be added to the data table, and the implementation manners of adding data rows may include:

When receiving the addition instruction, generate a second newly added row according to the addition instruction, write the corresponding row identifier in the row identifier column of the second newly added row, and write the current modification time in the timestamp column of the second newly added row;

Insert the second new row into the data table.

In this embodiment, the second newly added behavior is a line generated according to the addition instruction, and the second newly added line may be one or more.

Referring to Fig. 5, the last row in the data table shown in Fig. 5 can be generated according to the adding instruction, a new row ID is written in the row ID column of the row, and the current modification time is written in the timestamp column of the row, Insert the row into the data table, generate the data table shown in Figure 5, and complete the addition of data rows in the data table.

Step 105: when receiving the read data command, obtain at least one result row in the data table according to the read data command, and take the row with the latest modification time corresponding to each row identifier in the at least one result row to form a result table, Returns the part of the result table with the row ID column and timestamp column removed to the user.

When the user needs to read the data in the data table, the version with the latest modification time is returned to the user for each row ID in the data to be read, and the row ID column and the timestamp column are transparent to the user , the data table returned to the user does not contain the row ID column and the timestamp column, so that the user reads the modified data, which is equivalent to the data update.

Referring to FIG. 6 , assuming that the read data command needs to read all current data, all rows obtained by searching in the data table shown in FIG. 5 are used as result rows, and each row identifies the corresponding row with the latest modification time. The result table is formed, that is, the penultimate first, second, third, and fifth rows in the data table shown in Figure 5 form the result table, and the row ID column and the timestamp column in the result table are removed to generate the data table shown in Figure 6, namely In order to return the result to the user, what the user gets is the latest data corresponding to each row ID.

In addition, based on this embodiment, it is also possible to perform a data snapshot in the OLAP database, and the way to realize the data snapshot may include:

Receive a read snapshot command, and the read snapshot command includes a time point;

Find the row whose modification time in the timestamp column is less than or equal to the time point in the data table as the snapshot candidate row;

A snapshot table is formed by selecting the row with the latest modification time corresponding to each row identifier in the snapshot candidate rows, and returning the part of the snapshot table with the row identifier column and the timestamp column removed to the user.

However, when a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table, a prompt that the snapshot is not found is generated.

For the relevant description about implementing the data snapshot, reference may be made to the subsequent embodiments, which will not be described in this embodiment for the time being.

In this way, by recording the row ID and modification time of each row in the data table, when data needs to be modified, the row to be modified is modified, the row ID of the row to be modified is kept unchanged, and the latest modification time is recorded in the row to be modified , when the user reads the data, the data with the latest modification time is returned to the user for each row identifier. For the user, what is read is the modified data, which has the same effect as the data has actually been modified. It satisfies the requirement of realizing data update in OLAP database. In addition, when the user reads the snapshot, the data whose row identifier is less than or equal to the snapshot time point and has the latest modification time is returned to the user, thereby realizing the function of reading the snapshot in the OLAP database.

Referring to FIG. 7 , an embodiment of a method for implementing a data snapshot in an OLAP database provided in an embodiment of the present invention is shown, which may include the following steps:

Step 701: Add a row ID column and a timestamp column to the data table. The row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table.

The specific implementation of this step is similar to step 101 in the foregoing embodiment, and reference may be made to the foregoing embodiment for related descriptions, which will not be repeated here.

Step 702: Receive an instruction to read the snapshot, and the instruction to read the snapshot includes a time point.

Step 703 : Find the row in the data table whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row.

Step 704: From the rows to be selected in the snapshot, a row with the latest modification time corresponding to each row ID is taken to form a snapshot table, and the part of the snapshot table with the row ID column and the timestamp column removed is returned to the user.

In some possible implementations of the present invention, when a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table, a prompt that no snapshot is found is generated.

When the user needs to read the snapshot of the data table, a time point is given by the read snapshot command. First, according to the modification time in the timestamp column of the data table, at least one row less than or equal to the time point is obtained as the snapshot candidate row. There may be multiple rows of data with the same row ID in the row to be selected, and then the row with the latest modification time corresponding to each row ID is taken from the row to be selected in the snapshot to form a snapshot table. It is transparent to the user, so the part of the snapshot table that removes the row ID column and the timestamp column is returned to the user. In this way, the user gets a snapshot of the data table at a certain point in time.

Referring to Fig. 8, assuming that the time point included in the read snapshot instruction is "2016-10-0900:00:00", first obtain the row whose timestamp is less than this time point in the left table of Fig. 8, then in Fig. In the left table of 8, the data rows of the last two rows are removed as the snapshot candidate rows. In the snapshot candidate rows, there are two rows with the row ID "01" and the row ID "02", and the row ID is "03". There is one row in the row, then each row ID is taken from the row with the latest modification time to form a snapshot table, the row ID column and the timestamp column are removed from the snapshot table, and the data table shown in the right table of Figure 8 is generated and returned to the user as the Snapshot of a point in time.

In addition, based on this embodiment, data update in the OLAP database can also be implemented, and the way of implementing the data update can include:

When a modification instruction is received, the row to be modified is determined in the data table; the row to be modified is modified according to the modification instruction and the current modification time is written in the timestamp column of the row to be modified to generate the first new row; Insert additional rows into the data table. The specific implementation of determining the row to be modified in the data table may include: obtaining at least one row to be modified in the data table according to the modification instruction, and obtaining the latest modification time corresponding to each row identifier in the at least one row to be modified line as the line to be modified.

When receiving the addition instruction, generate a second newly added row according to the addition instruction, write the corresponding row identifier in the row identifier column of the second newly added row, and write the current modification time in the timestamp column of the second newly added row; Insert the second new row into the data table.

When the read data command is received, at least one result row is obtained in the data table according to the read data command, the row with the latest modification time corresponding to each row ID is taken from the at least one result row to form a result table, and the result table The part that removes the row ID column and the timestamp column is returned to the user.

For the method for updating data in the OLAP database, reference may be made to the description of the foregoing embodiment, which will not be repeated here.

In this way, by recording the row identifier and modification time of each row in the data table, when the user reads the snapshot, the data whose row identifier is less than or equal to the snapshot time point and has the latest modification time is returned to the user, thereby realizing the OLAP database. The ability to read snapshots in . In addition, when data needs to be modified, modify the row to be modified, keep the row ID of the row to be modified unchanged, and record the latest modification time in the row to be modified. When the user reads the data, it returns for each row ID. The data with the latest modification time is returned to the user, and the user can read the modified data, which has the same effect as the data has actually been modified, which satisfies the needs of realizing data update in the OLAP database.

Referring to FIG. 9 , an apparatus embodiment for implementing data update in an OLAP database provided in an embodiment of the present invention is shown, which may include:

The first adding unit 901 is used to add a row ID column and a timestamp column in the data table, the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table.

The determining unit 902 is configured to determine the row to be modified in the data table when the modification instruction is received.

In some possible implementations of the present invention, the determining unit may be specifically used for:

Obtain at least one row to be modified in the data table according to the modification instruction, and select the row with the latest modification time corresponding to each row identifier in the at least one row to be modified as the row to be modified.

The modifying unit 903 is configured to modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first newly added row.

The first inserting unit 904 is used for inserting the first newly added row into the data table.

The reading unit 905 is configured to obtain at least one result row in the data table according to the read data instruction when receiving the read data instruction, and fetch the row with the latest modification time corresponding to each row identifier in the at least one result row A result table is formed, and the part of the result table that removes the row ID column and the timestamp column is returned to the user.

In some possible implementations of the present invention, this embodiment may further include:

The second adding unit is configured to generate a second newly added row according to the adding instruction when receiving the adding instruction, write the corresponding row identifier in the row identifier column of the second newly added row, and write the corresponding row identifier in the row identifier column of the second newly added row, and the timestamp of the second newly added row column writes the current modification time;

The second inserting unit is used to insert the second newly added row into the data table.

The device for realizing data update in the OLAP database includes a processor and a memory, and the above-mentioned first adding unit, determining unit, modifying unit, first inserting unit and reading unit are all stored in the memory as program units, and are executed by the processor. The above-mentioned program units stored in the memory implement the corresponding functions.

The processor contains a kernel, and the kernel calls the corresponding program unit from the memory. The kernel can set one or more, and implement data update in the OLAP database by adjusting the kernel parameters.

Memory may include non-persistent memory in computer readable media, random access memory (RAM) and/or non-volatile memory, such as read only memory (ROM) or flash memory (flash RAM), the memory including at least one memory chip.

In this way, by recording the row ID and modification time of each row in the data table, when data needs to be modified, the row to be modified is modified, the row ID of the row to be modified is kept unchanged, and the latest modification time is recorded in the row to be modified , when the user reads the data, the data with the latest modification time is returned to the user for each row identifier. For the user, what is read is the modified data, which has the same effect as the data has actually been modified. It satisfies the requirement of realizing data update in OLAP database.

Referring to FIG. 10 , an apparatus embodiment for implementing a data snapshot in an OLAP database provided in an embodiment of the present invention is shown, which may include:

The adding unit 1001 is used for adding a row ID column and a timestamp column in the data table, the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table.

The receiving unit 1002 is configured to receive a read snapshot instruction, where the read snapshot instruction includes a time point.

The search unit 1003 is configured to search the data table for a row whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row.

The snapshot unit 1004 is configured to select a row with the latest modification time corresponding to each row identifier in the snapshot candidate rows to form a snapshot table, and return the part of the snapshot table with the row identifier column and the timestamp column removed to the user.

In some possible implementations of the present invention, this embodiment may further include:

The prompt unit is used to generate a prompt that a snapshot is not found when a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table.

The described device for realizing data snapshot in the OLAP database includes a processor and a memory, and the above-mentioned increasing unit, receiving unit, search unit and snapshot unit etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory. to achieve the corresponding function.

The processor includes a kernel, and the kernel calls the corresponding program unit from the memory. The kernel can set one or more, and implement data snapshots in the OLAP database by adjusting the kernel parameters.

Memory may include non-persistent memory in computer readable media, random access memory (RAM) and/or non-volatile memory, such as read only memory (ROM) or flash memory (flash RAM), the memory including at least one memory chip.

In this way, by recording the row identifier and modification time of each row in the data table, when the user reads the snapshot, the data whose row identifier is less than or equal to the snapshot time point and has the latest modification time is returned to the user, thus realizing the OLAP database. The ability to read snapshots in . In addition, when data needs to be modified, modify the row to be modified, keep the row ID of the row to be modified unchanged, and record the latest modification time in the row to be modified. When the user reads the data, it returns for each row ID. The data with the latest modification time is returned to the user. For the user, what the user can read is the modified data, which has the same effect as the data has actually been modified, which satisfies the needs of realizing data update in the OLAP database.

The present application also provides a computer program product that, when executed on a data processing device, is adapted to execute program code initialized with the following method steps:

A row identification column and a timestamp column are added to the data table, the row identification column is used to record the row identification of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table;

When receiving the modification instruction, determine the row to be modified in the data table;

Modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first new row;

inserting the first new row into the data table;

When a read data command is received, at least one result row is obtained in the data table according to the read data command, and a row with the latest modification time corresponding to each row identifier is taken from the at least one result row to form a composition A result table, returning the part of the result table with the row ID column and the timestamp column removed to the user.

The present application also provides another computer program product that, when executed on a data processing device, is adapted to execute program code initialized with the following method steps:

A row identification column and a timestamp column are added to the data table, the row identification column is used to record the row identification of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table;

receiving a read snapshot instruction, where the read snapshot instruction includes a time point;

Searching in the data table for a row whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row;

In the snapshot candidate rows, a row with the latest modification time corresponding to each row identifier is taken to form a snapshot table, and the part of the snapshot table excluding the row identifier column and the timestamp column is returned to the user.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

Memory may include non-persistent memory in computer readable media, random access memory (RAM) and/or non-volatile memory in the form of, for example, read only memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media includes both persistent and non-permanent, removable and non-removable media, and storage of information may be implemented by any method or technology. Information may be computer readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), Flash Memory or other memory technology, Compact Disc Read Only Memory (CD-ROM), Digital Versatile Disc (DVD) or other optical storage, Magnetic tape cartridges, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, excludes transitory computer-readable media, such as modulated data signals and carrier waves.

The above are merely examples of the present application, and are not intended to limit the present application. Various modifications and variations of this application are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims (10)

1. a method for realizing data update in OLAP database, is characterized in that, described method comprises: A row ID column and a timestamp column are added to the data table, the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table; The row identifier column and the timestamp column are hidden columns; When receiving the modification instruction, determine the row to be modified in the data table; Modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first new row; inserting the first new row into the data table; When a read data command is received, at least one result row is obtained in the data table according to the read data command, and a row with the latest modification time corresponding to each row identifier is taken from the at least one result row to form a composition A result table, returning the part of the result table with the row ID column and the timestamp column removed to the user. 2. The method according to claim 1, wherein the method further comprises: When an addition instruction is received, a second newly added row is generated according to the added instruction, the corresponding row identifier is written in the row identifier column of the second newly added row, and the timestamp column of the second newly added row is written in the row identifier column of the second added row. Write the current modification time; Insert the second new row into the data table. 3. The method according to claim 1, wherein the determining the row to be modified in the data table comprises: Obtain at least one row to be selected for modification in the data table according to the modification instruction, and select a row with the latest modification time corresponding to each row identifier in the at least one row to be selected for modification as the row to be modified. 4. a method for realizing data snapshot in OLAP database, is characterized in that, described method comprises: A row ID column and a timestamp column are added to the data table, the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record the modification time of each row in the data table; The row identifier column and the timestamp column are hidden columns; receiving a read snapshot instruction, where the read snapshot instruction includes a time point; Searching in the data table for a row whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row; In the snapshot candidate rows, a row with the latest modification time corresponding to each row identifier is taken to form a snapshot table, and the part of the snapshot table excluding the row identifier column and the timestamp column is returned to the user. 5. The method according to claim 4, wherein the method further comprises: When a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table, a prompt that no snapshot is found is generated. 6. A device for realizing data update in OLAP database, wherein the device comprises: The first adding unit is used to add a row identifier column and a timestamp column in the data table, the row identifier column is used to record the row identifier of each row in the data table, and the timestamp column is used to record the data table The modification time of each row in ; the row identification column and the timestamp column are hidden columns; a determining unit for determining the row to be modified in the data table when the modification instruction is received; a modification unit, configured to modify the row to be modified according to the modification instruction and write the current modification time in the timestamp column of the row to be modified to generate a first newly added row; a first inserting unit for inserting the first newly added row into the data table; The reading unit is configured to obtain at least one result row in the data table according to the read data instruction when receiving the read data instruction, and fetch the at least one result row corresponding to each row identifier with The row with the latest modification time constitutes a result table, and the part of the result table excluding the row ID column and the timestamp column is returned to the user. 7. The apparatus of claim 6, wherein the apparatus further comprises: The second adding unit is configured to generate a second newly added row according to the adding instruction when receiving the adding instruction, write the corresponding row identifier in the row identifier column of the second newly added row, and write the corresponding row identifier in the row identifier column of the second newly added row. The timestamp column of the new row is written to the current modification time; The second inserting unit is used for inserting the second newly added row into the data table. 8. The apparatus according to claim 6, wherein the determining unit is specifically configured to: Obtain at least one row to be selected for modification in the data table according to the modification instruction, and select a row with the latest modification time corresponding to each row identifier in the at least one row to be selected for modification as the row to be modified. 9. A device for realizing data snapshot in an OLAP database, wherein the device comprises: an adding unit for adding a row ID column and a timestamp column in the data table, the row ID column is used to record the row ID of each row in the data table, and the timestamp column is used to record each row in the data table The modification time of ; the row identification column and the timestamp column are hidden columns; a receiving unit, configured to receive a read snapshot instruction, where the read snapshot instruction includes a time point; a search unit, configured to search in the data table for a row whose modification time in the timestamp column is less than or equal to the time point as a snapshot candidate row; A snapshot unit, configured to select a row with the latest modification time corresponding to each row identifier in the snapshot to-be-selected row to form a snapshot table, and remove the row identifier column and the timestamp column from the snapshot table returned to the user. 10. The apparatus of claim 9, wherein the apparatus further comprises: The prompt unit is configured to generate a prompt that no snapshot is found when a row whose modification time in the timestamp column is less than or equal to the time point is not found in the data table.

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