You won't know until you test it. It varies for all situations. You don't know if you have a problem until you test it. Is there something stopping you from testing?
What you may not understand that it's not "redindexing" -- it's deleting one node from the index and inserting another. So the indexing will be slightly slower since the 1st pass is only doing an insert. However, you're not expanding the disk file so there's potential time savings there which may make up for it. Michael D. Black Senior Scientist NG Information Systems Advanced Analytics Directorate ________________________________ From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on behalf of LiranR [liran.rit...@gmail.com] Sent: Wednesday, August 24, 2011 6:55 AM To: sqlite-users@sqlite.org Subject: EXT :Re: [sqlite] Re indexing (if such a thing exist) performance mmm... I didnt state a problem, I stated a question: How much time will it take to reindex the new timestamp? As you can see, i do only update to the row. The things that changed are the data and the time stamp. Because the time stamp is PK i guess it will have to reindex the table, no? How bad in performance is it? Black, Michael (IS) wrote: > > What you're saying makes sense. But you haven't stated a problem... > > > > Are you far enough along you can show timing beween 1st and 2nd queue > fills? > > > > How long does it take you to insert your first million? > > How long does it take you to insert your second million? > > > > > > Michael D. Black > > Senior Scientist > > NG Information Systems > > Advanced Analytics Directorate > > > > ________________________________ > From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on > behalf of LiranR [liran.rit...@gmail.com] > Sent: Wednesday, August 24, 2011 6:39 AM > To: sqlite-users@sqlite.org > Subject: EXT :Re: [sqlite] Re indexing (if such a thing exist) performance > > > I use: > > ID (PK) | TimeStamp (PK) | data | data | and data ... > ------------------------------------------------------------- > 1 | 1000001 | float | float | float > 2 | 1000002 | float | float | float > 3 | 3 | float | float | float > 4 | 4 | float | float | float > ... | ... | float | float | float > > As you can see, the table is already has been filled, and its the second > time entering data. > the next row to update is row 3, which will be have TimeStamp 1000003. > Because the face that time stamp is always rising, i can't leave there > only > the number 3. Also, I have to use TimeStamp as PK (Primary Key) because of > the fact that when i want to read data from the table i search the table > by > timestamp. > > > Kees Nuyt wrote: >> >> On Wed, 24 Aug 2011 02:58:58 -0700 (PDT), LiranR >> <liran.rit...@gmail.com> wrote: >> >>> >>> 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). >> >> It will take about the same effort as deleting and inserting a >> row, or about twice as much as inserting a row. >> Show us your schema and we may be able to advise on optimizations. >> (output of .schema in the sqlite3 command line tool will do). >> >> Note: index is a resserved word. Using it as a column name is >> confusing. >> -- >> ( Kees Nuyt >> ) >> c[_] >> _______________________________________________ >> 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-tp32324832p32325716.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-tp32324832p32325797.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
