On Fri, Sep 16, 2016 at 9:56 PM, Jeff Janes <jeff.ja...@gmail.com> wrote: > On Fri, Sep 16, 2016 at 4:20 AM, Amit Kapila <amit.kapil...@gmail.com> > wrote: >> >> Currently README of hash module contain algorithms written in below form. >> >> The insertion algorithm is rather similar: >> >> pin meta page and take buffer content lock in shared mode >> loop: >> compute bucket number for target hash key >> release meta page buffer content lock >> if (correct bucket page is already locked) >> break >> release any existing bucket page lock (if a concurrent split happened) >> take heavyweight bucket lock in shared mode >> retake meta page buffer content lock in shared mode >> -- (so far same as reader) >> release pin on metapage >> .. >> .. >> >> I have mostly updated them in the patches I have proposed to improve >> hash index. However, each time I try to update them, I find that it >> is easy to follow the code than to read and understand the existing >> algorithm written in above form from README. >> >> Do others find it useful to maintain the algorithms in above form? > > > I think that having them all condensed into one place makes it easier to > think through the locking models to decide if there might be races or > deadlocks. If you only care about the algorithm for inserting in isolation, > I agree reading the code might be better. >
Thanks Jeff and Ken for the inputs. I will keep the algorithms updated in README of hash index. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
