Re: number of loaded/unloaded COPY rows - Mailing list pgsql-hackers

Also, can I get a context diff for the patch?  See the developers FAQ
for information on how our patch process works.  Thanks.

---------------------------------------------------------------------------

Volkan YAZICI wrote:
> On Dec 16 08:47, Bruce Momjian wrote:
> > I think an int64 is the proper solution. If int64 isn't really
> > 64-bits, the code should still work though.
> 
> (I'd prefer uint64 instead of an int64.) In src/include/c.h, in
> this or that way it'll assign a type for uint64, so there won't
> be any problem for both 64-bit and non-64-bit architectures.
> 
> I've attached the updated patch. This one uses uint64 and
> UINT64_FORMAT while printing uint64 value inside string.
> 
> I used char[20+1] as buffer size to store uint64 value's string
> representation. (Because, AFAIK, maximum decimal digit length of
> an [u]int64 equals to 2^64 - 1 = 20.) In this context, when I
> looked at the example usages (for instance as in
> backend/commands/sequence.c) it's stored in a char[100] buffer.
> Maybe we should define a constant in pg_config.h like
> INT64_PRINT_LEN. This will define a standard behaviour with
> INT64_FORMAT for using integers inside strings.
> 
> For instance:
>   char buf[INT64_PRINT_LEN+1];
>   snprintf(buf, sizeof(buf), INT64_FORMAT, var);
> 
> > In fact we have this TODO, which is related:
> > 
> >     * Change LIMIT/OFFSET and FETCH/MOVE to use int8
> > 
> > This requires the same type of change.
> > 
> > I have added this TODO:
> > 
> >     * Allow the count returned by SELECT, etc to be to represent
> >     as an int64 to allow a higher range of values
> >
> > This requires a change to es_processed, I think.
> 
> I think so. es_processed is defined as uint32. It should be
> uint64 too.
> 
> I tried to prepare a patch for es_processed issue. But when I look
> further in the code, found that there're lots of mixed usages of
> "uint32" and "long" for row count related trackings. (Moreover,
> as you can see from the patch, there's a problem with ULLONG_MAX
> usage in there.)
> 
> I'm aware of the patch's out-of-usability, but I just tried to
> underline some (IMHO) problems.
> 
> Last minute edit: Proposal: Maybe we can define a (./configure
> controlled) type like pg_int (with bounds like PG_INT_MAX) to use
> in counter related processes.
> 
> - * -
> 
> AFAIK, there're two ways to implement a counter:
> 
> 1. Using integer types supplied by the compiler, like uint64 as we
>    discussed above.
>    Pros: Whole mathematical operations are handled by the compiler.
>    Cons: Implementation is bounded by the system architecture.
>    
> 2. Using arrays to hold numeric values, like we did in the
>    implementation of SQL numeric types.
>    Pros: Value lengths bounded by available memory.
>    Cons: Mathematical operations have to be handled by software.
>          Therefore, this will cause a small overhead in performance
>          aspect compared to previous implementation.
> 
> I'm not sure if we can use the second implementation (in the
> performance point of view) for the COPY command's counter. But IMHO
> it can be agreeable for SELECT/INSERT/UPDATE/DELETE operations'
> counters. OTOH, by using this way, we'll form a proper method for
> counting without any (logical) bounds.
> 
> What's your opinion? If you aggree, I'll try to use the second
> implementation for counters - except COPY.
> 
> 
> Regards.
> 
> -- 
> "We are the middle children of history, raised by television to believe
> that someday we'll be millionaires and movie stars and rock stars, but
> we won't. And we're just learning this fact," Tyler said. "So don't
> fuck with us."

[ Attachment, skipping... ]

[ Attachment, skipping... ]

--  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