Re: [PROPOSAL] VACUUM Progress Checker.

On 11/19/15 7:29 PM, Amit Langote wrote:
>> Another option is to provide the means for the index scan routines to
>> >report their progress. Maybe every index AM won't use it, but it'd
>> >certainly be a lot better than staring at a long_running boolean.
> The boolean would be a workaround for sure. I'm also slightly tempted by
> the idea of instrumenting vacuum scans of individual index AM's bulkdelete
> methods. One precedent is how vacuum_delay_point() are sprinkled around in
> the code. Another problem to solve would be to figure out how to pass
> progress parameters around - via some struct or could they be globals just
> like VacuumCost* variables are...

It just occurred to me that we could do the instrumentation in
lazy_tid_reaped(). It might seem bad to do in increment for every tuple
in an index, but we're already doing a bsearch over the dead tuple list.
Presumably that's going to be a lot more expensive than an increment
operation.
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
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