Hi Ryan, Thanks a lot for your support. I had a trigger to update the one of the column in audio table on insert to audio table. That made this delay.
Thanks and Regards Deepak On Wednesday 30 September 2015 04:01 PM, Deepak Hegde wrote: > Hi Ryan, > > Please find my reply below. Thanks a lot. > > Thanks and Regards > Deepak > > On Wednesday 30 September 2015 03:30 PM, R.Smith wrote: >> >> On 2015-09-30 11:46 AM, Deepak Hegde wrote: >>> Hi All, >>> >>> I have a to copy entry from on database to another which have the >>> similar structure. >>> >>> So I am using the method of ATTACH the DB and INSERT statement to insert >>> the 200 entries at a time. >>> I have observed that as the entries in the copied database increases >>> event though I am inserting 200 entry only, time for insertion keeps on >>> increasing.//... >> Hi Deepak - (Not related to Mr. Chopra I trust?) > [DEEPAK]: No sir. >> The time taken to insert rows into a database is a function of the >> database size with several factors adding to it. >> >> Firstly, you need to use transactions to make the inserts faster if >> you are going to do multiple inserts. Secondly, it will be much faster >> if you insert using a SELECT query (as you do), but it can be the >> actual SELECT that takes longer to execute since I assume the >> original/source DB would have grown too. See taht you have good index >> for fast querying on the source DB. > [DEEPAK]: If the database reading have only 200 entry and I am doing > the same procedure than also same behavior is seen. So I thought Time > taken is for insertion and not for the reading. >> The time taken to insert items into a database (with already many >> items in it) is mostly due to needing to expand the indices of the >> target DB. If you have no Index at all (though you will still likely >> have the hidden rowid index) then theoretically the database can grow >> without using much time. For every Index you add, the time taken to >> insert will go up because the DB has to add and re-organize the B-Tree >> used for every index (In the standard case). > [DEEPAK]: I had attached the DB structure but that mail size was more > and got rejected. There is no index created externally by me. But there > are some index internally created by sqlite, this seems to be due to > unique constraint on column on the certain table like sqlite_autoindex_ALBUM_1 > This constrain is not present for the table AUDIO for which insertion is > happening, so for my understanding this index will not be invoked while > inserting. > So is rowid index will increase the time to this extent if the entry > count goes high? >> Some bit of time gets lost on the file-handling of large files once >> they grow significantly, but that is usually rather negligible >> compared to the Indexing factors. >> >> HTH, >> Ryan >> >> >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users at mailinglists.sqlite.org >> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >> > > >
