And in PostgreSQL you can do that with xmin and ctid. xmin holds the last transaction id to update/update the row and ctid holds the physical location of the tuple in the table. If you use these then you've got to do it with full knowledge of PostgreSQL's multiversion concurrency control and how that affects which tuples are visible when. You can augment that with the ctid = currtid(tableoid, ctid) function which will return the current valid ctid even if your known ctid is old. It also happens that if you can locate a record by ctid then you get lightning fast access since PostgreSQL knows exactly where to seek in the table to find it. I was writing some initial code to use this feature where multiple identity values were used a fallbacks: first ctid, then app object id or whatever else is normally used for identity.

__SIG__
printf "You are here %08x\n", unpack "L!", unpack "P4", pack "L!", B::svref_2object(sub{})->OUTSIDE

In reply to Re: Re: OO Perl & RDBMS Strategy Question by diotalevi
in thread OO Perl & RDBMS Strategy Question by DamnDirtyApe

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