Is there a need to remove entries from mapping?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
1
down vote

favorite












I am adding approximately 3 ~ 5 new entries into the mapping, while the old one will be obsolete after a week.



If the mapping grow larger, is it going to consume more gasses?



Is there a need for me to remove them since they are no longer needed.




solidity gas mapping




share|improve this question
























    up vote
    1
    down vote

    favorite












    I am adding approximately 3 ~ 5 new entries into the mapping, while the old one will be obsolete after a week.



    If the mapping grow larger, is it going to consume more gasses?



    Is there a need for me to remove them since they are no longer needed.




    solidity gas mapping




    share|improve this question






















      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      I am adding approximately 3 ~ 5 new entries into the mapping, while the old one will be obsolete after a week.



      If the mapping grow larger, is it going to consume more gasses?



      Is there a need for me to remove them since they are no longer needed.




      solidity gas mapping




      share|improve this question












      I am adding approximately 3 ~ 5 new entries into the mapping, while the old one will be obsolete after a week.



      If the mapping grow larger, is it going to consume more gasses?



      Is there a need for me to remove them since they are no longer needed.





      solidity gas mapping





      share|improve this question











      share|improve this question




      share|improve this question










      asked Aug 19 at 6:27









      s k

      2119




      2119




















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          3
          down vote













          You pass gas to store the value in the first place. There are no future charges for keeping the data there.



          That said, you can get a gas refund for deleting the existing data. That can only offset gas used for a new transaction. So if you can manage to delete the old ones while adding the new ones in the same transaction, you'll save gas (and thus ether) by doing so.






          share|improve this answer




















          • smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
            – s k
            Aug 19 at 14:05










          • That's correct.
            – smarx
            Aug 19 at 15:18










          Your Answer







          StackExchange.ready(function()
          var channelOptions =
          tags: "".split(" "),
          id: "642"
          ;
          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',
          convertImagesToLinks: false,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          bindNavPrevention: true,
          postfix: "",
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );








           

          draft saved


          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fethereum.stackexchange.com%2fquestions%2f56853%2fis-there-a-need-to-remove-entries-from-mapping%23new-answer', 'question_page');

          );

          Post as a guest

















          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          3
          down vote













          You pass gas to store the value in the first place. There are no future charges for keeping the data there.



          That said, you can get a gas refund for deleting the existing data. That can only offset gas used for a new transaction. So if you can manage to delete the old ones while adding the new ones in the same transaction, you'll save gas (and thus ether) by doing so.






          share|improve this answer




















          • smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
            – s k
            Aug 19 at 14:05










          • That's correct.
            – smarx
            Aug 19 at 15:18














          up vote
          3
          down vote













          You pass gas to store the value in the first place. There are no future charges for keeping the data there.



          That said, you can get a gas refund for deleting the existing data. That can only offset gas used for a new transaction. So if you can manage to delete the old ones while adding the new ones in the same transaction, you'll save gas (and thus ether) by doing so.






          share|improve this answer




















          • smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
            – s k
            Aug 19 at 14:05










          • That's correct.
            – smarx
            Aug 19 at 15:18












          up vote
          3
          down vote










          up vote
          3
          down vote









          You pass gas to store the value in the first place. There are no future charges for keeping the data there.



          That said, you can get a gas refund for deleting the existing data. That can only offset gas used for a new transaction. So if you can manage to delete the old ones while adding the new ones in the same transaction, you'll save gas (and thus ether) by doing so.






          share|improve this answer












          You pass gas to store the value in the first place. There are no future charges for keeping the data there.



          That said, you can get a gas refund for deleting the existing data. That can only offset gas used for a new transaction. So if you can manage to delete the old ones while adding the new ones in the same transaction, you'll save gas (and thus ether) by doing so.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Aug 19 at 6:30









          smarx

          15.8k1515




          15.8k1515











          • smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
            – s k
            Aug 19 at 14:05










          • That's correct.
            – smarx
            Aug 19 at 15:18
















          • smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
            – s k
            Aug 19 at 14:05










          • That's correct.
            – smarx
            Aug 19 at 15:18















          smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
          – s k
          Aug 19 at 14:05




          smarx, thanks for the answer. So adding an entry into a mapping (regardless if it has 0 or 1000000 entries) will always consume the same amount of gas right?
          – s k
          Aug 19 at 14:05












          That's correct.
          – smarx
          Aug 19 at 15:18




          That's correct.
          – smarx
          Aug 19 at 15:18












           

          draft saved


          draft discarded


























           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fethereum.stackexchange.com%2fquestions%2f56853%2fis-there-a-need-to-remove-entries-from-mapping%23new-answer', 'question_page');

          );

          Post as a guest
































































          -

          這個網誌中的熱門文章

          How to combine Bézier curves to a surface?

          圖片
          Clash Royale CLAN TAG #URR8PPP up vote 2 down vote favorite My aim is to smooth the terrain in a video game. Therefore I contrived an algorithm that makes use of Bézier curves of different orders. But this algorithm is defined in a two dimensional space for now. To shift it into the third dimension I need to somehow combine the Bézier curves. Given two curves in each two dimensions, how can I combine them to build a surface? I thought about something like a curve of a curve. Or maybe I could multiply them somehow. How can I combine them to cause the wanted behavior? Is there a common approach? In the image you can see the input, on the left, and the output, on the right, of the algorithm that works in a two dimensional space. For the real application there is a three dimensional input. The algorithm relays only on the adjacent tiles. Given these it will define the control points of the mentioned Bézier cur...
          閱讀完整內容

          Mutual Information Always Non-negative

          圖片
          Clash Royale CLAN TAG #URR8PPP up vote 10 down vote favorite 6 What is the simplest proof that mutual information is always non-negative? i.e., $I(X;Y)ge0$ probability-theory share | cite | improve this question edited Jun 17 '12 at 15:38 Cameron Buie 83.6k 7 71 154 asked Jun 17 '12 at 15:30 Omri 359 3 13 3 Convexity of the function $tmapsto tlog t$. – Did Jun 17 '12 at 15:33 In addition, the convexity properties require the coefficients in the linear combination sum 1. Then, as p(x,y) is a probability distribution, it fullfits such condition. – Francisco Javier Delgado Ceped Aug 10 at 18:44 add a comment  |  up vote 10 down vote favorite 6 What is the simplest proof that mutual information is always non-negative? i.e., $I(X;Y)ge0$ probability-theory share | cite | improve this question edited Jun 17 ...
          閱讀完整內容

          Why am i infinitely getting the same tweet with the Twitter Search API?

          圖片
          up vote 0 down vote favorite My code workes perfectly for other queries, but for one query I am infinitely getting the same tweet. I can't understand what the problem is. API call: query='Allergic asthma OR Nonallergic asthma OR Occupational asthma OR EIB OR Exercise-induced bronchoconstriction OR Nocturnal asthma OR Cough-variant asthma' new_tweets = api.search(q=searchQuery, count=100, since_id=since_id, lang='en',tweet_mode='extended') if not new_tweets: print("No more tweets found") break for tweet in new_tweets: if True: print(jsonpickle.encode(tweet._json, unpicklable=False)) my_file = open('searchTweets.txt','a') my_file.write(jsonpickle.encode(tweet._json, unpicklable=False)+'n') my_file.close() else: continue Output in file: https://pastebin.com/JmRCsTeE These are the JSONs of the same Tweet. Other queries that work: Breast cancer OR Prostate cancer OR Colon cancer OR Lung cancer Type 2 dia...
          閱讀完整內容