I believe that when using a transaction, i.e. Begin, Commit. SQLite will only perform the actual writing to file when Commit is made, therefore less disk I/O, or all I/O done at the end rather than after each insert and therefore better performance.
See documentation at:- http://www.sqlite.org/speed.html P.S. I'm sure someone else will give a better explanation. > -----Original Message----- > From: Cesar David Rodas Maldonado [mailto:[EMAIL PROTECTED] > Sent: 29 June 2006 16:12 > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] sqlite too slow for me? > > > I have a question for every body... > > > SQLite was very slow for my inserts (like 50000 inserts), with out > sincronization > > but when i put BEGIN; before start with my inserts is was > faster... like > 1000 times more... :D why is that? > > > On 6/28/06, Cesar David Rodas Maldonado <[EMAIL PROTECTED]> wrote: > > > > I dont know a lot about MySQL... but mysql is not so faster as you > > think... > > I have in my computer the mysql 5 is good, but sqlite is so > faster too!!! > > > > but MySQL has a query cache.... so i think the cache make > it seems more > > faster than sqlite... > > > > > > > > > > On 6/27/06, Péter Szabó <[EMAIL PROTECTED]> wrote: > > > > > > First, thank you all for the answers. > > > > > > > UNIQUE(col1, col4, col5, col2), > > > > > > Adding this would surely make the query run faster -- > provided that > > > SQLite chooses the right index. But I also use the > UNIQUE(col1, col4, > > > col5) constraint to ensure the uniqueness of these three > columns. So > > > instead I should have both > > > > > > UNIQUE(col1, col4, col5), > > > UNIQUE(col1, col4, col5, col2), > > > > > > but this would waste my disk space. > > > > > > I am wondering how can MySQL 4.1 be so fast compared to SQLite 3? > > > MySQL answers my query in 0.02 seconds, and SQLite answers in more > > > than 28 seconds. > > > > > > I guess that MySQL doesn't do any magic either ( i.e. it > operates in > > > O(Klog N) time, which appears to be just 0.02 seconds), but MySQL > > > recognises that it should use the UNIQUE(col1, col4, col5) index, > > > while SQLite poorly chooses some other index, maybe the PRIMARY > > > KEY(col1, col2, col3, col4, col5), which is just wrong. > Can someone > > > confirm that the SQLite is using the wrong index? Is it > possible to > > > deterministically rewrite the query to force SQLite use the right > > > index? > > > > > > > > DISCLAIMER: This information and any attachments contained in this email message is intended only for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution, forwarding, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by return email, and delete the original message immediately.
