Re: [sqlite] sqlite Query Optimizer

On 16 Oct 2014, at 11:07am, Prakash Premkumar wrote: > Are there any projects where , sqlite optimizer has been extended to add > System R The optimizer currently built into SQLite does the same job as what you're thinking of as "System R". It is not possible to use

Re: [sqlite] sqlite Query Optimizer

Thanks a lot Simon. Are there any projects where , sqlite optimizer has been extended to add System R or other algorithms ? I browsed through the github repository and could not find any. Thanks a lot for your time. Regards Prakash On Thu, Oct 16, 2014 at 12:49 PM, Simon Slavin

Re: [sqlite] sqlite Query Optimizer

On 16 Oct 2014, at 7:50am, Prakash Premkumar wrote: > Does sqlite implement the pointers in the System R Algorithm ? SQLite does not implement the System R Algorithm, so no, it doesn't implement the pointers from System R. It implements the algorithms described in the

Re: [sqlite] sqlite Query Optimizer

Thanks for your reply Simon. I have read through those links. Does sqlite implement the pointers in the System R Algorithm ? Like assigning selectivity factors for predicates in where clause? Link to System R Algorithm: https://www.cs.duke.edu/courses/spring03/cps216/papers/selinger-etal-1979.pdf

Re: [sqlite] sqlite Query Optimizer

On 15 Oct 2014, at 12:54pm, Prakash Premkumar wrote: > I'm trying to understand the sqlite select query optimizer. It works by > assigning costs to each relation in FROM clause. That is only a little bit of how it works. Have you read these ?

[sqlite] sqlite Query Optimizer

Hi, I'm trying to understand the sqlite select query optimizer. It works by assigning costs to each relation in FROM clause. As far as I understand, it primarily uses the logarithmic estimate of the number of rows in the relation. Query optimization algorithms like IBM System R algorithm assigns