Re: [sqlite] Is there a way to measure query time in sqlite at runtime?

On 16 Nov 2012, at 11:26pm, 杨苏立 Yang Su Li wrote: > I want to measure the execution time of each sql statement in sqlite. > > I understand in sqlite shell you could just do .timer on, but I am > wondering how to do it in a pogrammerable way so that I could know how much >

Re: [sqlite] light weight write barriers

> The more money you pay for your storage, the less likely this is to be an > issue (high end SSD's, enterprise class arrays, etc don't have volatile write > caches and most SAS drives perform reasonably well with the write cache > disabled). "Performance" without a write cache is a physical

Re: [sqlite] Is there a way to measure query time in sqlite at runtime?

On Sat, Nov 17, 2012 at 1:26 AM, 杨苏立 Yang Su Li wrote: > I want to measure the execution time of each sql statement in sqlite. Use sqlite3_profile() to register a profiler callback for a database connection that will be called for every SQL statement you execute on that

Re: [sqlite] light weight write barriers

Chris Friesen, on 11/15/2012 05:35 PM wrote: The easiest way to implement this fsync would involve three things: 1. Schedule writes for all dirty pages in the fs cache that belong to the affected file, wait for the device to report success, issue a cache flush to the device (or request ordering

Re: [sqlite] light weight write barriers

杨苏立 Yang Su Li, on 11/15/2012 11:14 AM wrote: 1. fsync actually does two things at the same time: ordering writes (in a barrier-like manner), and forcing cached writes to disk. This makes it very difficult to implement fsync efficiently. Exactly! However, logically they are two distinctive

Re: [sqlite] light weight write barriers

David Lang, on 11/15/2012 07:07 AM wrote: There's no such thing as "barrier". It is fully artificial abstraction. After all, at the bottom of your stack, you will have to translate it either to cache flush, or commands order enforcement, or both. When people talk about barriers, they are

[sqlite] Is there a way to measure query time in sqlite at runtime?

I want to measure the execution time of each sql statement in sqlite. I understand in sqlite shell you could just do .timer on, but I am wondering how to do it in a pogrammerable way so that I could know how much time a sql statement takes when applications are accessing the database at real

Re: [sqlite] light weight write barriers

On 11/16/2012 10:54 AM, Howard Chu wrote: Ric Wheeler wrote: On 11/16/2012 10:06 AM, Howard Chu wrote: David Lang wrote: barriers keep getting mentioned because they are a easy concept to understand. "do this set of stuff before doing any of this other set of stuff, but I don't care when any

Re: [sqlite] light weight write barriers

On 11/16/2012 10:06 AM, Howard Chu wrote: David Lang wrote: barriers keep getting mentioned because they are a easy concept to understand. "do this set of stuff before doing any of this other set of stuff, but I don't care when any of this gets done" and they fit well with the requirements of