Horton

Re: Patch: Write Amplification Reduction Method (WARM)

Pavan Deolasee <pavan.deolasee@gmail.com>

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From: Pavan Deolasee <pavan.deolasee@gmail.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Jaime Casanova <jaime.casanova@2ndquadrant.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-01-31T14:04:36Z
Lists: pgsql-hackers 
On Tue, Jan 31, 2017 at 7:21 PM, Alvaro Herrera <alvherre@2ndquadrant.com>
wrote:

> Pavan Deolasee wrote:
> > On Thu, Jan 26, 2017 at 2:38 AM, Alvaro Herrera <
> alvherre@2ndquadrant.com>
> > wrote:
>
> > > The simple_heap_update + CatalogUpdateIndexes pattern is getting
> > > obnoxious.  How about creating something like catalog_heap_update which
> > > does both things at once, and stop bothering each callsite with the
> WARM
> > > stuff?
> >
> > What I realised that there are really 2 patterns:
> > 1. simple_heap_insert, CatalogUpdateIndexes
> > 2. simple_heap_update, CatalogUpdateIndexes
> >
> > There are only couple of places where we already have indexes open or
> have
> > more than one tuple to update, so we call CatalogIndexInsert directly.
> What
> > I ended up doing in the attached patch is add two new APIs which combines
> > the two steps of each of these patterns. It seems much cleaner to me and
> > also less buggy for future users. I hope I am not missing a reason not to
> > do combine these steps.
>
> CatalogUpdateIndexes was just added as a convenience function on top of
> a very common pattern.  If we now have a reason to create a second one
> because there are now two very common patterns, it seems reasonable to
> have two functions.  I think I would commit the refactoring to create
> these functions ahead of the larger WARM patch, since I think it'd be
> bulky and largely mechanical.  (I'm going from this description; didn't
> read your actual code.)
>

Sounds good. Should I submit that as a separate patch on current master?

Thanks,
Pavan

-- 
 Pavan Deolasee                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Implement SortSupport for macaddr data type

  2. Simplify check of modified attributes in heap_update

  3. Remove direct uses of ItemPointer.{ip_blkid,ip_posid}

  4. Fix CatalogTupleInsert/Update abstraction for case of shared indstate.

  5. Provide CatalogTupleDelete() as a wrapper around simple_heap_delete().

  6. Band-aid fix for incorrect use of view options as StdRdOptions.

  7. Update visibility map in the second phase of vacuum.

  8. Avoid having two copies of the HOT-chain search logic.

  9. Postgres95 1.01 Distribution - Virgin Sources