Metadata search via N-gram index

Patent metadata

Field	Value
Publication number	US-12411850-B2
Application number	US-202418656126-A
Country	US
Kind code	B2
Filing date	May 6, 2024
Priority date	Oct 29, 2021
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

As described herein, a N-Gram index may be created and the search may be conducted using the index, which will lead to faster search results. The N-Gram index may also include partial N-Gram components to capture more relevant data. Moreover, as described herein, the search may also take into account recent log data that has not yet been indexed. Techniques for building an index store using log data and efficiently searching the index store and log data to process search requests are described herein.

First claim

What is claimed is:

1. A method comprising:
receiving an instruction to enable logging of database operations of a source table stored in a network-based data system;
in response to receiving the instruction, scanning existing data objects stored in a metadata database associated with the source table to generate index records for a N-gram index associated with past database operations performed on the source table;
scanning the index records in the N-gram index to generate index statistics;
updating the N-gram index based on new logs from a log cache to generate a new version of the N-gram index;
enabling search of the new version of the N-gram index, the search using the index statistics for execution;
receiving, from a user, a search request including a search string; and
processing the search request based on the new version of the N-gram index;
wherein the new logs are updated in the N-gram index in a separate process than processing the search request.

2. The method of claim 1 , further comprising:
loading, in the log cache, log data associated with new logs not yet reflected in the N-Gram index;
retrieving index records matching the search string and storing the index records in an index cache;
merging the log data in the log cache with the index records in the index cache to generate merged data; and
generating results of the search request based on the merged data in the separate process than updating the new logs in the N-gram index.

3. The method of claim 2 , further comprising:
updating metadata associated with the N-Gram index to facilitate searching of the N-Gram index based on the index record;
in response to the search request, loading index statistics of the N-Gram index;
retrieving metadata associated with the N-Gram index; and
performing post filtering of the merged log data and matched index records.

4. The method of claim 2 , further comprising:
performing a permission check on the merged data to determine that the user has access rights to the merged data.

5. The method of claim 1 , wherein the past database operations include a delete operation, the method further comprising:
generating an index deletion log record associated with the delete operation;
marking an index record in the N-Gram index associated with the delete operation; and
based on at least one search associated with an older version of the N-Gram index being completed, deleting the marked index record based on the index deletion log record.

6. The method of claim 5 , wherein the marked index record is not deleted in a same transaction as the delete operation.

7. The method of claim 1 , wherein N-Gram index includes partial N-grams for at least last N characters of a name.

8. The method of claim 1 , wherein index records for the N-Gram index include a prefix portion indicating whether a corresponding index record is for a prefix substring.

9. The method of claim 1 , wherein the log includes an account ID, a chunk ID, a timestamp, a domain ID, and an entity ID.

10. The method of claim 1 , wherein each index record of the N-Gram index includes an account ID, a prefix portion, an index version, a domain ID, and a parent entity ID.

11. A system comprising:
at least one hardware processor; and
at least one memory storing instructions that, when executed by the at least one hardware processor, cause the at least one hardware processor to perform operations comprising:
receiving an instruction to enable logging of database operations of a source table stored in a network-based data system;
in response to receiving the instruction, scanning existing data objects stored in a metadata database associated with the source table to generate index records for a N-gram index associated with past database operations performed on the source table;
scanning the index records in the N-gram index to generate index statistics;
updating the N-gram index based on new logs from a log cache to generate a new version of the N-gram index;
enabling search of the new version of the N-gram index, the search using the index statistics for execution;
receiving, from a user, a search request including a search string; and
processing the search request based on the new version of the N-gram index;
wherein the new logs are updated in the N-gram index in a separate process than processing the search request.

12. The system of claim 11 , the operations further comprising:
loading, in the log cache, log data associated with new logs not yet reflected in the N-Gram index;
retrieving index records matching the search string and storing the index records in an index cache;
merging the log data in the log cache with the index records in the index cache to generate merged data; and
generating results of the search request based on the merged data in the separate process than updating the new logs in the N-gram index.

13. The system of claim 12 , the operations further comprising:
updating metadata associated with the N-Gram index to facilitate searching of the N-Gram index based on the index record;
in response to the search request, loading index statistics of the N-Gram index;
retrieving metadata associated with the N-Gram index; and
performing post filtering of the merged log data and matched index records.

14. The system of claim 12 , the operations further comprising:
performing a permission check on the merged data to determine that the user has access rights to the merged data.

15. The system of claim 11 , wherein the past database operations include a delete operation, the operations further comprising:
generating an index deletion log record associated with the delete operation;
marking an index record in the N-Gram index associated with the delete operation; and
based on at least one search associated with an older version of the N-Gram index being completed, deleting the marked index record based on the index deletion log record.

16. The system of claim 15 , wherein the marked index record is not deleted in a same transaction as the delete operation.

17. The system of claim 11 , wherein N-Gram index includes partial N-grams for at least last N characters of a name.

18. The system of claim 11 , wherein index records for the N-Gram index include a prefix portion indicating whether a corresponding index record is for a prefix substring.

19. The system of claim 11 , wherein the log includes an account ID, a chunk ID, a timestamp, a domain ID, and an entity ID.

20. The system of claim 11 , wherein each index record of the N-Gram index includes an account ID, a prefix portion, an index version, a domain ID, and a parent entity ID.

21. A machine-storage medium embodying instructions that, when executed by a machine, cause the machine to perform operations comprising:
receiving an instruction to enable logging of database operations of a source table stored in a network-based data system;
in response to receiving the instruction, scanning existing data objects stored in a metadata database associated with the source table to generate index records for a N-gram index associated with past operations performed on the source table;
scanning the index records in the N-gram index to generate index statistics;
updating the N-gram index based on new logs from a log cache to generate a new version of the N-gram index;
enabling search of the new version of the N-gram index, the search using the index statistics for execution;
receiving, from a user, a search request including a search

Assignees

• Snowflake Inc

Inventors

• Chan Lin
• Chen Tianyi
• Dageville Benoit
• Kang Yiming
• Luo Jun
• Mahesh Nithin
• Robinson Eric
• Smith Brian

Classifications

• G06F21/6218

  to a system of files or objects, e.g. local or distributed file system or database · CPC title

• G06F7/14

  Merging, i.e. combining at least two sets of record carriers each arranged in the same ordered sequence to produce a single set having the same ordered sequence · CPC title

• G06F21/6227

  where protection concerns the structure of data, e.g. records, types, queries · CPC title

• G06F16/2379

  Updates performed during online database operations; commit processing · CPC title

• G06F16/2228 Primary

  Indexing structures · CPC title