Hello, Do you truncate the table before iterating again ?
I don't think it really effect performance, if you start from 1 or 10000001. They are just number. You don't need to re-index your table. Indexes are created automatically at time of insertion/update/delete. So even if you delete old Data before starting new iteration it will do re-index at no additional cost. In my test I create a Index in database which have 1Million rows on numeric field took less than a minute. But if you create index before insertion, then there is nothing like re-index. And it works just same/similar speed. Sumit -----Original Message----- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of LiranR Sent: 24 August 2011 15:29 To: sqlite-users@sqlite.org Subject: Re: [sqlite] Re indexing (if such a thing exist) performance Hi, Thanks for the answer, but i think you didn't understand what i asked. I use primary key index in my table. When i finish to fill the table, row after row, i want to start all over again and update the table from row 1 to row 1000000. The difference is that in the second time, the index of the first row wont be 1, but 1000001, and then i will update the second row and it's index will be 1000002, and so on... (when i reach the 1000000 row, i update it with the index 2000000, and than again, first row will be update with index 2000001). My question is - Does it take heavy performance to reindex the row every time (because the row get another index number - in this example, a number that is bigger by 1000000 than the last row's index number). Vikasumit wrote: > > Hello, > > IF you create index Primary key it automatically index the Information, > but > if not you can always create a separate index for your field(s). When > Index > are present at time of insertion or update index will also get update to > include information. That do not REindex complete table. So performance > won't be an issue if you use Index. But if you don't use index the > performace will be WAY TOO bad and every request can take lot of time. I > did > about 1 M row update in 9minute with indexes and other stuffs. But without > index same code took 30 minute to update only 40K records. > > Sumit > > -----Original Message----- > From: sqlite-users-boun...@sqlite.org > [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of LiranR > Sent: 24 August 2011 14:11 > To: sqlite-users@sqlite.org > Subject: [sqlite] Re indexing (if such a thing exist) performance > > > Hi all!! > In my project, i insert rows, one by one, to a fixed size table (1000000 > rows for example). When i reach the end of the table, i enter data to the > first row and then the seocond and so on. If i have indexes (primary > keys), > lets say from 1 to 1000000, and now i reached the end, and update the > first > row with index 1001, does it have to reindex? > How much time will it take to reindex? because i will update the second > row > later with index 1002 and i have to reindex it too, if its true, and i am > worry about the performance of such a thing. > > -- > View this message in context: > http://old.nabble.com/Reindexing-%28if-such-a-thing-exist%29-performance-tp3 > 2324832p32324832.html > Sent from the SQLite mailing list archive at Nabble.com. > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- View this message in context: http://old.nabble.com/Reindexing-%28if-such-a-thing-exist%29-performance-tp3 2324832p32325213.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
