Here is a patch with updated WAL behavior. I'm not certain about MAXALIGN for size of appended tuple. Currently if anyone calls PageIndexTupleOverwrite() with unalligned tuple it will ereport(ERROR). I suspect that it should allign size instead.
Also I suspect that PageIndexTupleOverwrite() should make a call to ItemIdSetNormal() to pretend it is generic function and not just a private part of GiST. Best regards, Andrey Borodin, Octonica & Ural Federal University. 2016-07-04 22:59 GMT+05:00 Andrew Borodin <boro...@octonica.com>: > Thank you, Alvaro. > > Yes, now I see. I'll update gistRedoPageUpdateRecord() to work > accordingly with patched gistplacetopage(). > Also, i've noticed that PageAddItem uses MAXALIGN() macro to calculate > tuple size. So, PageIndexTupleOverwrite should behave the same. > > About PageIndexDeleteNoCompact() in BRIN. I do not see why > PageIndexDeleteNoCompact() is not a good solution instead of > PageIndexTupleOverwrite? Will it mark tuple as unused until next > PageAddItem will use it's place? > > Best regards, Andrey Borodin, Octonica & Ural Federal University. > > 2016-07-04 22:16 GMT+05:00 Alvaro Herrera <alvhe...@2ndquadrant.com>: >> Andrew Borodin wrote: >>> Thank you, Amit. >>> >>> Currently, if WAL reconstruct page in another order it won't be a problem. >> >> We require that replay of WAL leads to identical bytes than the >> original. Among other things, this enables use of a tool that verifies >> that WAL is working correctly simply by comparing page images. So >> please fix it instead of just verifying that this works for GiST. >> >> By the way, BRIN indexes have a need of this operation too. The current >> approach is to call PageIndexDeleteNoCompact followed by PageAddItem. >> I suppose it would be beneficial to use your new routine there too. >> >> -- >> Álvaro Herrera http://www.2ndQuadrant.com/ >> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
PageIndexTupleOverwrite v3.patch
Description: Binary data
-- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
