Обсуждение: LOCK.tag(figuring out granularity of lock)

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LOCK.tag(figuring out granularity of lock)

От
"Jenny -"
Дата:
following is taken from postgresql-7.3.2/src/backend/storage/lmgr/readme:

"If we are setting a table level lockboth the blockId and tupleId (in an item pointer this is calledthe position) are
setto invalid, if it is a page level lock theblockId is valid, while the tupleId is still invalid.  Finally ifthis is a
tuplelevel lock (we currently never do this) then boththe blockId and tupleId are set to valid specifications.  "
 

how do we check whether blockId and tupleId of LOCK.tag are valid or 
invalid?
is blockId same as tag.objId.blkno?  what field in LOCK.tag is tupleId?
thanks
jenny

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Re: LOCK.tag(figuring out granularity of lock)

От
Alvaro Herrera
Дата:
On Fri, Aug 08, 2003 at 12:15:07PM -0700, Jenny - wrote:
> following is taken from postgresql-7.3.2/src/backend/storage/lmgr/readme:

[...]

Is this on a crontab or something?  It has gotten very annoying lately.

-- 
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Right now the sectors on the hard disk run clockwise, but I heard a rumor that
you can squeeze 0.2% more throughput by running them counterclockwise.
It's worth the effort. Recommended."  (Gerry Pourwelle)


Re: LOCK.tag(figuring out granularity of lock)

От
Bruce Momjian
Дата:
Alvaro Herrera wrote:
> "Right now the sectors on the hard disk run clockwise, but I heard a rumor that
> you can squeeze 0.2% more throughput by running them counterclockwise.
> It's worth the effort. Recommended."  (Gerry Pourwelle)

In relation to your signature, I assume you have seen this joke:
http://www.netfunny.com/rhf/jokes/95q1/jpreviews.html

The helicopter part is the funniest.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073
 


Re: LOCK.tag(figuring out granularity of lock)

От
Alvaro Herrera
Дата:
On Fri, Aug 08, 2003 at 03:49:36PM -0400, Bruce Momjian wrote:
> Alvaro Herrera wrote:
> > "Right now the sectors on the hard disk run clockwise, but I heard a rumor that
> > you can squeeze 0.2% more throughput by running them counterclockwise.
> > It's worth the effort. Recommended."  (Gerry Pourwelle)
> 
> In relation to your signature, I assume you have seen this joke:
> 
>     http://www.netfunny.com/rhf/jokes/95q1/jpreviews.html
> 
> The helicopter part is the funniest.

:-D

Yeah, I read that and actually extracted the quote from there.

As a small boy I used to read Jerry Pournelle's commentary on Byte.  (Or
was it PC World?  I don't remember.)  They were strange to me, and I
always thought life was like that for people in the USA, i.e. hardware
falling from the sky and always the getting latest and greatest of all
sorts of machinery and software.  I couldn't imagine what was this about
phoning someone to get support, much less paying fees.

The satire made me remember all that and I couldn't help quoting it on
my sigs.

-- 
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Porque Kim no hacia nada, pero, eso sí,
con extraordinario éxito" ("Kim", Kipling)