[postgis-devel] [SoC] GSoC 2021 - Week 8 Report - Implement pre-sorting methods before GiST index building

[Han Wang]

Hi all,
I am here to share with you my Week6 report. You can also find it at [1]

Coding Week 8 (26th July - 1st August)
<https://trac.osgeo.org/postgis/wiki/ImplementSortingMethodsBeforeGistIndexBuilding#CodingWeek826thJuly-1stAugust>

*Coding Phase *:

   - Complete the tests of Buffer Hit and Execution Time of index query
   performance with random data
   - Write a document[2] with the test result

*Plans for next week*:

   - Connect with mentors and the community for the decision of pre-sort
   methods
   - Check the page status of different pre-sort methods.


I forced an index scan in a large data query scenario so the buffer hit
number of the pre-sort methods is many more than a sequence scan one. More
details about index scan, sequence scan and bitmap scan can be found at
[3]. Now I try to query a small area in the whole table and some results
are listed in the document.
If you have any questions, please let me know.

[1]
https://trac.osgeo.org/postgis/wiki/ImplementSortingMethodsBeforeGistIndexBuilding
[2]
https://docs.google.com/document/d/1m4oxBAsKCyjAnYmkCmQ0X_ltiid5tliFwF3rtdzlKsc/edit?usp=sharing
[3]
https://www.cybertec-postgresql.com/en/postgresql-indexing-index-scan-vs-bitmap-scan-vs-sequential-scan-basics/

Best regards,
Han
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-devel/attachments/20210803/0f1bd967/attachment.html>