Frequency dependent partial index

• US 10,459,947 B2
• Filed: 02/05/2016
• Issued: 10/29/2019
• Est. Priority Date: 02/05/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cui, Kai Feng, Li, Shuo, Liu, Shu Hua, Yang, Xin Ying
• Primary Examiner(s): Hu, Jensen
• Application Number:
  US15/016,744
• Publication Number:
  US 20170228449A1
• Time in Patent Office: 1,362 Days
• Field of Search: 707744
• CPC Class Codes: G06F 16/221 Column-oriented storage; Management thereof
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/278 Data partitioning, e.g. horizontal or vertical partitioning

Abstract

Using historical queries to determine database columns to populate a partial database. A partial database is created based, at least in part, on key values related to columns in a database for which the columns are most frequently accessed.

Claims

1. A method comprising:

receiving, by one or more processors, a database containing a plurality of columns;

determining, by the one or more processors, a key index for the database, wherein the key index includes a plurality of pointers to a plurality of records of the database;

determining, by the one or more processors, one or more access frequency values for columns associated with the key index;

determining, by the one or more processors, for a plurality of key values in the key index, a frequency of switching of a given key value in a given column associated with the key index to a column associated with a partial key index, wherein switching includes both of (i) an addition of the given key value to a column of the partial key index and (ii) a removal of the given key value from the column associated with the key index;

generating, by the one or more processors, the partial key index based, at least in part, on (a) the one or more access frequency values for the columns in the key index; and

(b) respective frequency of switching of key values for the columns in the key index, wherein the partial key index includes a subset of pointers from the plurality of pointers of the key index; and

generating, by the one or more processors, a partial database based on the partial key index, wherein the partial database includes a subset of rows from the database.

2. The method of claim 1, further comprising:

removing, responsive to receiving an access threshold as an input, a second set of columns from the partial index, wherein a set of access frequency values associated with the second set of columns are below the access threshold.

3. The method of claim 2, wherein the access threshold is one percent of the set of historical queries.

4. A computer program product comprising:

one or more computer-readable storage media and program instructions stored on the one or more computer-readable storage media, the program instructions comprising;

program instructions to receive a database containing a plurality of columns;

program instructions to determine a key index for the database, wherein the key index includes a plurality of pointers to a plurality of records of the database;

program instructions to determine one or more access frequency values for columns associated with the key index;

program instructions to determine for a plurality of key values in the key index, a frequency of switching of a given key value in a given column associated with the key index to a column associated with a partial key index, wherein switching includes both of (i) an addition of the given key value to a column of the partial key index and (ii) a removal of the given key value from the column associated with the key index;

program instructions to generate the partial key index based, at least in part, on (a) the one or more access frequency values for the columns in the key index; and

(b) respective frequency of switching of key values for the columns in the key index, wherein the partial key index includes a subset of pointers from the plurality of pointers of the key index; and

program instructions to generate a partial database based on the partial key index, wherein the partial database includes a subset of rows from the database.

5. The computer program product of claim 4, the program instructions further comprising:

program instructions to remove, responsive to receiving an access threshold as an input, a second set of columns from the partial key index, wherein a set of access frequency values associated with the second set of columns are below the access threshold.

6. The computer program product of claim 5, wherein the access threshold is one percent of the set of historical queries.

7. A computer system comprising:

one or more computer processors;

one or more computer readable storage media; and

program instructions stored on the computer readable storage media for execution by at least one of the one or more processors, the program instructions comprising;

program instructions to receive a database containing a plurality of columns;

program instructions to determine a key index for the database, wherein the key index includes a plurality of pointers to a plurality of records of the database;

program instructions to determine one or more access frequency values for columns associated with the key index;

program instructions to determine for a plurality of key values in the key index, a frequency of switching of a given key value in a given column associated with the key index to a column associated with a partial key index, wherein switching includes both of (i) an addition of the given key value to a column of the partial key index and (ii) a removal of the given key value from the column associated with the key index; and

program instructions to generate the partial key index based, at least in part, on (a) the one or more access frequency values for the columns in the key index; and

(b) respective frequency of switching of key values for the columns in the key index, wherein the partial key index includes a subset of pointers from the plurality of pointers of the key index; and

program instructions to generate a partial database based on the partial key index, wherein the partial database includes a subset of rows from the database.

8. The computer system of claim 7, further comprising:

program instructions to remove, responsive to receiving an access threshold as an input, a second set of columns from the partial key index, wherein a set of access frequency values associated with the second set of columns are below the access threshold.

9. The computer system of claim 8, wherein the access threshold level is one percent of the set of historical queries.