Django database cache TIMEOUT - make backend delete row












2














I'm not sure what Django database cache does with expired entries but it seems that they remain in the database.



I want Django to delete them after they expire because their size is huge and there can be unlimited number of different keys.



CACHES = {
'default': {
'BACKEND': 'django.core.cache.backends.db.DatabaseCache',
'LOCATION': 'cache_table',
'TIMEOUT': 60 * 20,
}
}


I use cache on filtered list of objects and this filter contais number and char fields.



Is it possible?










share|improve this question



























    2














    I'm not sure what Django database cache does with expired entries but it seems that they remain in the database.



    I want Django to delete them after they expire because their size is huge and there can be unlimited number of different keys.



    CACHES = {
    'default': {
    'BACKEND': 'django.core.cache.backends.db.DatabaseCache',
    'LOCATION': 'cache_table',
    'TIMEOUT': 60 * 20,
    }
    }


    I use cache on filtered list of objects and this filter contais number and char fields.



    Is it possible?










    share|improve this question

























      2












      2








      2


      2





      I'm not sure what Django database cache does with expired entries but it seems that they remain in the database.



      I want Django to delete them after they expire because their size is huge and there can be unlimited number of different keys.



      CACHES = {
      'default': {
      'BACKEND': 'django.core.cache.backends.db.DatabaseCache',
      'LOCATION': 'cache_table',
      'TIMEOUT': 60 * 20,
      }
      }


      I use cache on filtered list of objects and this filter contais number and char fields.



      Is it possible?










      share|improve this question













      I'm not sure what Django database cache does with expired entries but it seems that they remain in the database.



      I want Django to delete them after they expire because their size is huge and there can be unlimited number of different keys.



      CACHES = {
      'default': {
      'BACKEND': 'django.core.cache.backends.db.DatabaseCache',
      'LOCATION': 'cache_table',
      'TIMEOUT': 60 * 20,
      }
      }


      I use cache on filtered list of objects and this filter contais number and char fields.



      Is it possible?







      python django caching django-database django-cache






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 11 at 21:52









      Milano

      4,2031141112




      4,2031141112
























          1 Answer
          1






          active

          oldest

          votes


















          1














          It isn't possible to purge expired entries as they expire. This is one of the many reasons you probably don't want to use the database cache in production!



          If possible, you should switch to a different cache backend (I prefer Redis). If you can't, you do have a few other options:




          1. If you know the cache keys you want to purge, you can use the low-level cache API to directly delete the keys you want to purge.


          2. You could tweak the MAX_ENTRIES and/or CULL_FREQUENCY cache arguments to limit the overall size of the cache.


          3. You could poke into the database directly (perhaps from a background task or cron job), manually running some SQL like DELETE FROM cache_table WHERE expires < now() (I haven't tested this, but I think it should work).







          share|improve this answer





















            Your Answer






            StackExchange.ifUsing("editor", function () {
            StackExchange.using("externalEditor", function () {
            StackExchange.using("snippets", function () {
            StackExchange.snippets.init();
            });
            });
            }, "code-snippets");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "1"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53253618%2fdjango-database-cache-timeout-make-backend-delete-row%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            1














            It isn't possible to purge expired entries as they expire. This is one of the many reasons you probably don't want to use the database cache in production!



            If possible, you should switch to a different cache backend (I prefer Redis). If you can't, you do have a few other options:




            1. If you know the cache keys you want to purge, you can use the low-level cache API to directly delete the keys you want to purge.


            2. You could tweak the MAX_ENTRIES and/or CULL_FREQUENCY cache arguments to limit the overall size of the cache.


            3. You could poke into the database directly (perhaps from a background task or cron job), manually running some SQL like DELETE FROM cache_table WHERE expires < now() (I haven't tested this, but I think it should work).







            share|improve this answer


























              1














              It isn't possible to purge expired entries as they expire. This is one of the many reasons you probably don't want to use the database cache in production!



              If possible, you should switch to a different cache backend (I prefer Redis). If you can't, you do have a few other options:




              1. If you know the cache keys you want to purge, you can use the low-level cache API to directly delete the keys you want to purge.


              2. You could tweak the MAX_ENTRIES and/or CULL_FREQUENCY cache arguments to limit the overall size of the cache.


              3. You could poke into the database directly (perhaps from a background task or cron job), manually running some SQL like DELETE FROM cache_table WHERE expires < now() (I haven't tested this, but I think it should work).







              share|improve this answer
























                1












                1








                1






                It isn't possible to purge expired entries as they expire. This is one of the many reasons you probably don't want to use the database cache in production!



                If possible, you should switch to a different cache backend (I prefer Redis). If you can't, you do have a few other options:




                1. If you know the cache keys you want to purge, you can use the low-level cache API to directly delete the keys you want to purge.


                2. You could tweak the MAX_ENTRIES and/or CULL_FREQUENCY cache arguments to limit the overall size of the cache.


                3. You could poke into the database directly (perhaps from a background task or cron job), manually running some SQL like DELETE FROM cache_table WHERE expires < now() (I haven't tested this, but I think it should work).







                share|improve this answer












                It isn't possible to purge expired entries as they expire. This is one of the many reasons you probably don't want to use the database cache in production!



                If possible, you should switch to a different cache backend (I prefer Redis). If you can't, you do have a few other options:




                1. If you know the cache keys you want to purge, you can use the low-level cache API to directly delete the keys you want to purge.


                2. You could tweak the MAX_ENTRIES and/or CULL_FREQUENCY cache arguments to limit the overall size of the cache.


                3. You could poke into the database directly (perhaps from a background task or cron job), manually running some SQL like DELETE FROM cache_table WHERE expires < now() (I haven't tested this, but I think it should work).








                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 11 at 22:25









                jacobian

                4,08021511




                4,08021511






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Stack Overflow!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53253618%2fdjango-database-cache-timeout-make-backend-delete-row%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    Full-time equivalent

                    Bicuculline

                    さくらももこ