<div dir="ltr"><div></div><div><h3 id="m_2761007492899234331gmail-CodingWeek109thAugust-15thAugust" style="font-family:Arial,Verdana,"Bitstream Vera Sans",Helvetica,sans-serif;letter-spacing:-0.018em;break-after:avoid;font-size:14px;border-bottom:1px dashed rgb(221,221,221);padding:0.2em 0.3em 0.1em;color:rgb(0,0,0)"><div style="color:rgb(34,34,34);font-family:Arial,Helvetica,sans-serif;font-size:small;font-weight:400;letter-spacing:normal">Hi all,</div><div style="color:rgb(34,34,34);font-family:Arial,Helvetica,sans-serif;font-size:small;font-weight:400;letter-spacing:normal">I am here to share with you my Week 10 report. You can also find it at [1]</div></h3><h3 id="m_2761007492899234331gmail-CodingWeek109thAugust-15thAugust" style="font-family:Arial,Verdana,"Bitstream Vera Sans",Helvetica,sans-serif;letter-spacing:-0.018em;break-after:avoid;font-size:14px;border-bottom:1px dashed rgb(221,221,221);padding:0.2em 0.3em 0.1em;color:rgb(0,0,0)">Coding Week 10 (9th August - 15th August)<a href="https://trac.osgeo.org/postgis/wiki/ImplementSortingMethodsBeforeGistIndexBuilding#CodingWeek109thAugust-15thAugust" title="链接到这一节" style="text-decoration-line:none;color:rgb(215,215,215);border:none;font-size:0.8em;vertical-align:text-top" target="_blank"></a></h3><h3 id="m_2761007492899234331gmail-m_-8639790829994434745gmail-CodingWeek92ndAugust-8stAugust" style="font-family:Arial,Verdana,"Bitstream Vera Sans",Helvetica,sans-serif;letter-spacing:-0.018em;break-after:avoid;font-size:14px;border-bottom:1px dashed rgb(221,221,221);padding:0.2em 0.3em 0.1em;color:rgb(0,0,0)"><p style="font-family:Verdana,Arial,"Bitstream Vera Sans",Helvetica,sans-serif;font-size:13px;font-weight:400;letter-spacing:normal"><strong>Coding Phase </strong>:</p><ul style="font-family:Verdana,Arial,"Bitstream Vera Sans",Helvetica,sans-serif;font-size:13px;font-weight:400;letter-spacing:normal"><li>Do more traversal tests</li><li>Fix the issue of <code style="color:rgb(102,0,0);border:1px solid rgb(238,221,204);border-radius:0.25em;padding:0px 0.3em;background:rgb(250,250,250)">gist_page_items</code></li></ul><p style="font-family:Verdana,Arial,"Bitstream Vera Sans",Helvetica,sans-serif;font-size:13px;font-weight:400;letter-spacing:normal"><strong>Plans for next week</strong>:</p><ul style="font-family:Verdana,Arial,"Bitstream Vera Sans",Helvetica,sans-serif;font-size:13px;font-weight:400;letter-spacing:normal"><li>Submit the final evaluation</li><li>Plan for a 32 bit hash function</li><li>Finish the documents</li></ul></h3></div><div>I have updated the document[2] for more tests. The pre-sort function works normally. But from this test, I think the current implementation of the fast index building method with pre-sorting may cause a loss of performance. </div><div>The pre-sorting function entry in Postgres does not check the leaf elements of a GiST index. And the first 32-bit of a 64bit Morton/Hilbert hash code as a datum key may reduce the precision significantly. </div><div>From my perspective, a 32 bit hash function may be necessary next. If you have any questions or suggestions, please let me know! You can reach me at the #postgis channel in matrix.</div><div><div><br></div><div>[1] <a href="https://trac.osgeo.org/postgis/wiki/ImplementSortingMethodsBeforeGistIndexBuilding" target="_blank">https://trac.osgeo.org/postgis/wiki/ImplementSortingMethodsBeforeGistIndexBuilding</a><br></div><div>[2] <a href="https://docs.google.com/document/d/1m4oxBAsKCyjAnYmkCmQ0X_ltiid5tliFwF3rtdzlKsc/edit?usp=sharing" target="_blank">https://docs.google.com/document/d/1m4oxBAsKCyjAnYmkCmQ0X_ltiid5tliFwF3rtdzlKsc/edit?usp=sharing</a></div><div><br></div><div>Best regards,</div><div>Han</div></div></div>