You're welcome. Yes, database administrators can create an index as desired. However, creating multiple cin indexes in a single column with different methods will cause performance issues. I don't think using expressions when using like and ilike is a correct use for query performance. It doesn't hurt to add an extra expression string for the "exact" and "iexact" operators. However, it will be a huge cost for full text search.
Tom Forbes <t...@tomforb.es>, 28 Şub 2021 Paz, 13:39 tarihinde şunu yazdı: > Thank you for the clarification! I think the biggest argument for this > change is the fact that uppercasing Unicode can cause incorrect results to > be returned. > > Given that we now have much better support for custom index types, perhaps > we should change this? We need a custom expression index anyway, so it > might not be a huge ask to say “now you should use a gin index”? > > Tom > > On Sun, 28 Feb 2021 at 09:28, Tom Forbes <t...@tomforb.es> wrote: > >> Thank you for the clarification! >> >> On Sun, 28 Feb 2021 at 09:23, Mesut Öncel <mesutonce...@gmail.com> wrote: >> >>> Yes, 7 years ago I reviewed the ticket for the updated code, but there >>> are problems there.https: //code.djangoproject.com/ticket/32485 The >>> ticket I opened has the necessary details. If you want more details, I can >>> make the necessary explanations. >>> >>> Tom Forbes <t...@tomforb.es>, 28 Şub 2021 Paz, 12:36 tarihinde şunu >>> yazdı: >>> >>>> Unless I’m missing something, the ticket you linked was last updated 7 >>>> years ago with two now-broken images. Which ticket did you open with the >>>> examples? >>>> >>>> Tom >>>> >>>> On Sun, 28 Feb 2021 at 08:31, Mesut Öncel <mesutonce...@gmail.com> >>>> wrote: >>>> >>>>> The reason I opened all the problems in a single ticket was to show >>>>> the disadvantages of the "UPPER" function used in the "icontains" >>>>> operator.I think that instead of using "UPPER (column) like" used in the >>>>> Django ORM filter method, the "icontains" operator should use the "ilike" >>>>> operator and this should be changed in the source code I specified in the >>>>> ticket. From the query examples I added to the ticket, you can see that >>>>> the >>>>> query "UPPER (column) like" generated by the "icontains" operator has a >>>>> performance problem and produces incorrect results. If you use "ilike" >>>>> instead of "UPPER (column)" in the icontains operator, the 2 problems I >>>>> mentioned will be solved. >>>>> >>>>> Tom Forbes <t...@tomforb.es>, 28 Şub 2021 Paz, 01:17 tarihinde şunu >>>>> yazdı: >>>>> >>>>>> Hey, >>>>>> I think it would be best if you opened a new ticket explaining your >>>>>> issue and the performance problems you’ve found (especially around >>>>>> Turkish >>>>>> characters). I’m not entirely clear what you wish to be changed: you wish >>>>>> for an expression index to be created automatically? >>>>>> >>>>>> Tom >>>>>> >>>>>> On Sat, 27 Feb 2021 at 21:13, Mesut Öncel <mesutonce...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> Hi, >>>>>>> I opened the ticket https://code.djangoproject.com/ticket/3575. In >>>>>>> this ticket, I wanted to prove the effect of UPPER function used in >>>>>>> icontains operator on indexes and query result. UPPER function causes >>>>>>> performance problems regarding indexing in PostgreSQL. Another issue is >>>>>>> that it does not give correct results especially for Turkish characters. >>>>>>> >>>>>>> Database administrators do not want to add individual indexes in >>>>>>> this regard. Because adding more than one index to the same column in >>>>>>> full >>>>>>> text search will negatively affect cost and performance. >>>>>>> >>>>>>> An expression index should be created to prevent performance loss in >>>>>>> database queries to be used outside the framework. However, the >>>>>>> existence >>>>>>> of such an index should be notified to everyone who uses this database, >>>>>>> and >>>>>>> the use of "UPPER (name) ilike '% AA%" instead of "ilike" should be >>>>>>> encouraged. This will cause PostgreSQL to block the "ilike" operator. >>>>>>> >>>>>>> If you give the necessary approval in this regard, I want to open a >>>>>>> pull request for the field specified on the ticket. >>>>>>> >>>>>>> Thanks. >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "Django developers (Contributions to Django itself)" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to django-developers+unsubscr...@googlegroups.com. >>>>>>> To view this discussion on the web visit >>>>>>> https://groups.google.com/d/msgid/django-developers/ba167e5c-49dd-4d96-a2c4-855082639d4en%40googlegroups.com >>>>>>> <https://groups.google.com/d/msgid/django-developers/ba167e5c-49dd-4d96-a2c4-855082639d4en%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "Django developers (Contributions to Django itself)" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>> send an email to django-developers+unsubscr...@googlegroups.com. >>>>>> >>>>> To view this discussion on the web visit >>>>>> https://groups.google.com/d/msgid/django-developers/CAFNZOJOr7N%3DT_7Jwj5fqv2ec3UuoVqrjCUwC_C9s_3-sckHbwQ%40mail.gmail.com >>>>>> <https://groups.google.com/d/msgid/django-developers/CAFNZOJOr7N%3DT_7Jwj5fqv2ec3UuoVqrjCUwC_C9s_3-sckHbwQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>> . >>>>>> >>>>> >>>>> >>>>> -- >>>>> İyi çalışmalar. Saygılarımla. >>>>> >>>>> *Mesut Öncel* >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Django developers (Contributions to Django itself)" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to django-developers+unsubscr...@googlegroups.com. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/django-developers/CAACgSnQE4KJyKNU7hi1REQFXCVyo07QhBw6F2QUxUP5m%2BK06qQ%40mail.gmail.com >>>>> <https://groups.google.com/d/msgid/django-developers/CAACgSnQE4KJyKNU7hi1REQFXCVyo07QhBw6F2QUxUP5m%2BK06qQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Django developers (Contributions to Django itself)" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to django-developers+unsubscr...@googlegroups.com. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/django-developers/CAFNZOJOBzXOTSsE-i1cudhGgZ84_tV30%2B40kp%3D0JQnw7xwDnmA%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/django-developers/CAFNZOJOBzXOTSsE-i1cudhGgZ84_tV30%2B40kp%3D0JQnw7xwDnmA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> >>> >>> -- >>> İyi çalışmalar. Saygılarımla. >>> >>> *Mesut Öncel* >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Django developers (Contributions to Django itself)" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to django-developers+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-developers/CAACgSnR8dP8%2BJxsKir4HCmZX2quKDOE1xHV75GHMSRhZXafvUQ%40mail.gmail.com >>> <https://groups.google.com/d/msgid/django-developers/CAACgSnR8dP8%2BJxsKir4HCmZX2quKDOE1xHV75GHMSRhZXafvUQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "Django developers (Contributions to Django itself)" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to django-developers+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-developers/CAFNZOJOioUG7isbZRtc7iHhO3XAFR5-cic-N_npaih4MSncUDw%40mail.gmail.com > <https://groups.google.com/d/msgid/django-developers/CAFNZOJOioUG7isbZRtc7iHhO3XAFR5-cic-N_npaih4MSncUDw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- İyi çalışmalar. Saygılarımla. *Mesut Öncel* -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/CAACgSnQG4P0sYD%3D49mywCAMP7zqA-bOeRJj2r3wm1kfwqvcgCQ%40mail.gmail.com.
