Обсуждение: Open 7.3 items, with names
I have added the names of the people who have the power to complete each
item. It may not be the original author.
---------------------------------------------------------------------------
P O S T G R E S Q L
7 . 3 O P E N I T E M S
Current at ftp://candle.pha.pa.us/pub/postgresql/open_items.
Source Code Changes
-------------------
Point-in-time recovery - status? (J.R., Richard)
Allow easy display of usernames in a group (pg_hba.conf uses groups now)
Reindex/btree shrinkage - does reindex need work, can btree be shrunk?
display locks - ready? (Bruce)
Prepared statements - ready? (Tom)
Schema handling - ready? interfaces? client apps?
ecpg and bison issues - solved? (Michael)
improve macros in new tuple header code (Manfred)
have pg_dumpall dump out db privilege and per-user/db settings
fix BeOS and QNX4 ports
fix implicit type coercions that are worse
integrate or remove new libpqxx
integrate or add to gborg Pg:DBD
handle lack of secondary passwords (Bruce)
move pg_resetxlog and pg_controldata to main tree, add -f flag (Bruce)
Allow PL/PgSQL functions to return sets (Neil)
Agree on PGXLOG/-X handling (Thomas)
Documentation Changes
---------------------
Mention foreign keys and SERIAL dependencies will not be in 7.2 loaded tables
Document need to add permissions to loaded functions and languages
-- 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
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Reindex/btree shrinkage - does reindex need work, can btree be shrunk?
I think there is zero probability that anything will be finished on this
in the next two weeks, considering that (a) no one is working on it,
and (b) it's not a small task. Push it back to TODO.
> Schema handling - ready? interfaces? client apps?
You can put my name on this for backend, psql, and pg_dump issues. I am
not sure what needs to be done in the other client-side code.
> improve macros in new tuple header code (Manfred)
Since I was the one griping, not Manfred, it's probably my job to fix
this.
regards, tom lane
Tom Lane wrote: > Bruce Momjian <pgman@candle.pha.pa.us> writes: > > Reindex/btree shrinkage - does reindex need work, can btree be shrunk? > > I think there is zero probability that anything will be finished on this > in the next two weeks, considering that (a) no one is working on it, > and (b) it's not a small task. Push it back to TODO. Done. Also, we do now have contrib/reindexdb, so it is there for people to use until we get it fixed. That is a step forward, and it is a documented problem in 7.3 too. > > Schema handling - ready? interfaces? client apps? > > You can put my name on this for backend, psql, and pg_dump issues. I am > not sure what needs to be done in the other client-side code. I am worried about the other stuff. I just added "DROP COLUMN" to the open items list to make sure that is dealt with too. > > improve macros in new tuple header code (Manfred) > > Since I was the one griping, not Manfred, it's probably my job to fix > this. OK, but I thought Manfred was going to address this when he got back from vacation, but he is back now. I assume you are saying that he isn't quite sure what you want and that you will have to do it. OK. -- 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
On Fri, 16 Aug 2002 01:05:07 -0400 (EDT), Bruce Momjian
<pgman@candle.pha.pa.us> wrote:
>
> P O S T G R E S Q L
>
> 7 . 3 O P E N I T E M S
>
>improve macros in new tuple header code (Manfred)
ISTM there's no consensus about what "improve" means. I tried to
start discussing this after my vacation, but apparently people had
better things to do.
On Wed, 07 Aug 2002 16:16:14 +0200, I wrote ("Heap tuple header
issues"):
:. Transaction and command ids, performance
:
:I offered to provide cheaper versions of GetCmin and GetCmax to be
:used by the tqual routines. These version would reduce additional CPU
:work from two infomask compares to one. Is this still considered an
:issue?
However, I don't think this would lead to any measurable difference.
:. Transaction and command ids, robustness
:
:I'm still of the opinion that putting *more* knowledge into the SetXxx
:macros is the way to go. The runaway INSERT bug could as well have
:been fixed by changing SetCmax to do nothing, if HEAP_XMAX_INVALID is
:set, and changing SetXmaxInvalid to set HEAP_XMAX_INVALID. Likewise I
:would change SetXmax to set HEAP_XMAX_INVALID, if xid ==
:InvalidTransactionId, or reset it, if != (not sure about this). Same
:for SetXminInvalid and SetXmin.
This is the main point of disagreement: Tom Lane wants lighter
macros, I want heavier macros. Which direction shall we go?
:Further, I'll try to build a regression test using statement timeout
:to detect runaway INSERT/UPDATE (the so called "halloween" problem).
This won't hurt anyway. I'll start working on this.
BTW, my changes have been criticized with words like "vague unease",
"zero confidence", "very obviously not robust", "do not trust the
current code at all" etc., while from day one all my patches have
passed all regression tests. This makes me wonder whether there is
something wrong with the regression tests ...
:. Oids
:
:I was a bit surprised that these patches went in so smoothly, must be
:due to the fact that there was a lot of work to do at that time.
:Personnally I feel that these changes are more dangerous than the
:Xmin/Cid/Xmax patches; and I ask the hackers to review especially
:part 2, which contains changes to the executor and even to bootstrap.
:. Oids, t_infomask
:
:There has been no comment from a tool developer.
:. Oids, heap_getsysattr
:
:We thought that a TupleDesc parameter would have to be added for this
:function. However, tests showed that heap_getsysattr is not called to
:get the oid, when the tuple doesn't have an oid: "ERROR: Attribute
:'oid' not found".
:. Oids, micro tuning
:
:There are a few places, where storing an oid in a local variable might
:be a little faster than fetching it several times from a heap tuple
:header.
However, I don't think this would lead to any measurable difference.
:. Overall performance
:
:If Joe Conway can be talked into running OSDB benchmarks with old and
:new heap tuple header format, I'll provide patches and instructions to
:easily switch between versions. Or, Joe, can you tell me, what I need
:to have and need to do to set up a benchmarking environment?
With Joe's help (thanks again, Joe) I've managed to setup a
benchmarking environment and I am continuously testing different
configurations for a week now. There are issues with OSDB which I
plan to bring up later when things cool down, but a first anawhat
seems to show that with the reduced heap tuple header size we get a
speed improvement of up to 3%, especially when the database is
significantly larger than system memory. When the database size is
only a small fraction of available memory, results vary so widely that
I cannot tell whether the new heap tuple macros are a loss or a win.
:
:. CVS
:
:There have been a lot of "CVS broken" messages in the past few days.
:When I tried
: cvs -z3 log heapam.c
:I got
:| cvs server: failed to create lock directory for `/projects/cvsroot/pgsql/src/backend/access/heap'
(/projects/cvsroot/pgsql/src/backend/access/heap/#cvs.lock):No such file or directory
:| cvs server: failed to obtain dir lock in repository `/projects/cvsroot/pgsql/src/backend/access/heap'
:| cvs [server aborted]: read lock failed - giving up
:
:Is this a temporary problem or did a miss any planned changes?
AFAIK I have to re-checkout everything.
ServusManfred
Manfred Koizar wrote:
> On Fri, 16 Aug 2002 01:05:07 -0400 (EDT), Bruce Momjian
> <pgman@candle.pha.pa.us> wrote:
> >
> > P O S T G R E S Q L
> >
> > 7 . 3 O P E N I T E M S
> >
> >improve macros in new tuple header code (Manfred)
>
> ISTM there's no consensus about what "improve" means. I tried to
> start discussing this after my vacation, but apparently people had
> better things to do.
OK.
> On Wed, 07 Aug 2002 16:16:14 +0200, I wrote ("Heap tuple header
> issues"):
> :. Transaction and command ids, performance
> :
> :I offered to provide cheaper versions of GetCmin and GetCmax to be
> :used by the tqual routines. These version would reduce additional CPU
> :work from two infomask compares to one. Is this still considered an
> :issue?
>
> However, I don't think this would lead to any measurable difference.
Yep.
> :. Transaction and command ids, robustness
> :
> :I'm still of the opinion that putting *more* knowledge into the SetXxx
> :macros is the way to go. The runaway INSERT bug could as well have
> :been fixed by changing SetCmax to do nothing, if HEAP_XMAX_INVALID is
> :set, and changing SetXmaxInvalid to set HEAP_XMAX_INVALID. Likewise I
> :would change SetXmax to set HEAP_XMAX_INVALID, if xid ==
> :InvalidTransactionId, or reset it, if != (not sure about this). Same
> :for SetXminInvalid and SetXmin.
>
> This is the main point of disagreement: Tom Lane wants lighter
> macros, I want heavier macros. Which direction shall we go?
Could you or Tom explain that in a way that others could understand.
My guess is that you want the sanity checks in the macros, and Tom wants
more of them in the main code?
> :Further, I'll try to build a regression test using statement timeout
> :to detect runaway INSERT/UPDATE (the so called "halloween" problem).
>
> This won't hurt anyway. I'll start working on this.
>
> BTW, my changes have been criticized with words like "vague unease",
> "zero confidence", "very obviously not robust", "do not trust the
> current code at all" etc., while from day one all my patches have
> passed all regression tests.
I totally agree with you here. You code has been great, and it did
something (reduce tuple size) that no one else thought possible.
> This makes me wonder whether there is
> something wrong with the regression tests ...
However, I should add that the regression tests test only a small subset
of how the database has to operate. There are so many bizarre
conditions that we can't test them all.
-- 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
On Fri, 16 Aug 2002 12:25:37 -0400 (EDT), Bruce Momjian
<pgman@candle.pha.pa.us> wrote:
>Manfred Koizar wrote:
>> This is the main point of disagreement: Tom Lane wants lighter
>> macros, I want heavier macros. Which direction shall we go?
>
>Could you or Tom explain that in a way that others could understand.
I'm not sure we understand each other :-)
>My guess is that you want the sanity checks in the macros, and Tom wants
>more of them in the main code?
I guess we agree on having the sanity checks in the macros. It's more
on what the macros are allowed to change and what decisions they are
allowed to take. Do the following quotes make it clearer?
:On Sat, 20 Jul 2002 16:27:14 -0400, Tom Lane <tgl@sss.pgh.pa.us>
:wrote:
:>I'd recommend redesigning the HeapTupleHeaderSet macros so that they
:>do not do any setting of t_infomask bits, or even take any conditional
:>action based on them,
to which I replied on Sun, 21 Jul 2002 23:00:22 +0200:
:The HEAP_XMIN_IS_XMAX bit is exclusively managed by these macros.
:Pulling the handling of this bit out of the macros and spreading it to
:the places, where the macros are used, cannot make the whole thing
:more robust. This would mean, the caller had to decide whether to
:store Cmax into t_cid or t_xmax...
Tom:
:> but solely Assert() that the bits are already
:>in the appropriate state to allow storing of the value to be stored.
:>Then, all uses have to be checked to ensure that t_infomask is coerced
:>into the right state *before* doing HeapTupleHeaderSetFoo.
me:
:Apart from HEAP_XMIN_IS_XMAX this was my intention; we already do
:this with HEAP_MOVED. I could add an assertion to SetCmax:
: Assert(!((tup)->t_infomask & HEAP_XMAX_INVALID));
:
:OTOH I thought about putting *more* logic into the macros to make
:their use less fragile. For example SetXmaxInvalid could set the
:HEAP_XMAX_INVALID bit, likewise SetCminInvalid with XMIN_INVALID.
>> BTW, my changes have been criticized with words like "vague unease",
>> "zero confidence", "very obviously not robust", "do not trust the
>> current code at all" etc., while from day one all my patches have
>> passed all regression tests.
>
>I totally agree with you here. You code has been great, and it did
>something (reduce tuple size) that no one else thought possible.
Thanks a lot! But I was not fishing for compliments, I was just
preparing for the next sentence: There is something wrong with the
regression tests. In fact "vague unease" more than once was a proper
description for my own feelings when I posted a patch, because I
didn't know whether I could trust the tests. If core developers share
this unease, I find myself in good company.
>> This makes me wonder whether there is
>> something wrong with the regression tests ...
>
>However, I should add that the regression tests test only a small subset
>of how the database has to operate.
So, please, could you add to TODO:
* Add more regression tests
>There are so many bizarre
>conditions that we can't test them all.
When Tom Lane recently posted a way to reproduce a bug ("No one parent
tuple was found", CASE 1) I thought about how to add this case to the
regression tests, but we have no vehicle for testing concurrent
transactions. TODO:
* Build a test vehicle for concurrent transactions* Add even more regression tests
ServusManfred