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BUG #17932: Cannot select big bytea values(>500MB)
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* BUG #17932: Cannot select big bytea values(>500MB)
@ 2023-05-15 09:48  PG Bug reporting form <noreply@postgresql.org>
  0 siblings, 1 reply; 3+ messages in thread

From: PG Bug reporting form @ 2023-05-15 09:48 UTC (permalink / raw)
  To: pgsql-bugs@lists.postgresql.org; +Cc: haduchiep@gmail.com

The following bug has been logged on the website:

Bug reference:      17932
Logged by:          Hans Lee
Email address:      haduchiep@gmail.com
PostgreSQL version: 13.10
Operating system:   linux
Description:        

Dear Support Team,

I created a big bytea value and try to select it from a table, I get 
an error, something like: "ERROR:  invalid memory alloc request size 
...".
it means i can insert data into table but then i can't even work 
with it. is it a bug? could you please help me to solve this Problem. 
Thank you very much for your support

Best Regards
Hiep



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: BUG #17932: Cannot select big bytea values(>500MB)
@ 2023-05-16 01:58  John Naylor <john.naylor@enterprisedb.com>
  parent: PG Bug reporting form <noreply@postgresql.org>
  0 siblings, 1 reply; 3+ messages in thread

From: John Naylor @ 2023-05-16 01:58 UTC (permalink / raw)
  To: haduchiep@gmail.com; pgsql-bugs@lists.postgresql.org

On Mon, May 15, 2023 at 5:21 PM PG Bug reporting form <
noreply@postgresql.org> wrote:

> I created a big bytea value and try to select it from a table, I get
> an error, something like: "ERROR:  invalid memory alloc request size
> ...".
> it means i can insert data into table but then i can't even work
> with it. is it a bug? could you please help me to solve this Problem.
> Thank you very much for your support

This is a known (but not documented as far as I know) issue, but it also
depends on the data contents and how the value is retrieved. Possible
workarounds:

1. If the data is largely printable ASCII, then try
setting "bytea_output" to "escape":

https://www.postgresql.org/docs/devel/runtime-config-client.html#GUC-BYTEA-OUTPUT

2. Request binary transmission in your application (if possible), for
example "show_binary_results" in

https://www.postgresql.org/docs/devel/libpq-example.html

3. COPY out using binary format

--
John Naylor
EDB: http://www.enterprisedb.com

^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: BUG #17932: Cannot select big bytea values(>500MB)
@ 2023-05-18 07:23  duc hiep ha <haduchiep@googlemail.com>
  parent: John Naylor <john.naylor@enterprisedb.com>
  0 siblings, 0 replies; 3+ messages in thread

From: duc hiep ha @ 2023-05-18 07:23 UTC (permalink / raw)
  To: John Naylor <john.naylor@enterprisedb.com>; +Cc: pgsql-bugs@lists.postgresql.org

Hello John Naylor,

Thank you very much for your support. After setting the "bytea_output" to
"escape" and increasing the Java heap size of DBeaver (to 8GB), I can now
see the big column (bytea > 500MB). I am still in the testing phase and
haven't finished yet, but I wonder if clients with small RAM will be able
to select these big columns or if bytea_output=escape will be visible in
the application. Could you please explain this to me in more detail?

Thanks

Vào Th 3, 16 thg 5, 2023 vào lúc 08:58 John Naylor <
john.naylor@enterprisedb.com> đã viết:

> On Mon, May 15, 2023 at 5:21 PM PG Bug reporting form <
> noreply@postgresql.org> wrote:
>
> > I created a big bytea value and try to select it from a table, I get
> > an error, something like: "ERROR:  invalid memory alloc request size
> > ...".
> > it means i can insert data into table but then i can't even work
> > with it. is it a bug? could you please help me to solve this Problem.
> > Thank you very much for your support
>
> This is a known (but not documented as far as I know) issue, but it also
> depends on the data contents and how the value is retrieved. Possible
> workarounds:
>
> 1. If the data is largely printable ASCII, then try
> setting "bytea_output" to "escape":
>
>
> https://www.postgresql.org/docs/devel/runtime-config-client.html#GUC-BYTEA-OUTPUT
>
> 2. Request binary transmission in your application (if possible), for
> example "show_binary_results" in
>
> https://www.postgresql.org/docs/devel/libpq-example.html
>
> 3. COPY out using binary format
>
> --
> John Naylor
> EDB: http://www.enterprisedb.com
>

^ permalink  raw  reply  [nested|flat] 3+ messages in thread


end of thread, other threads:[~2023-05-18 07:23 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2023-05-15 09:48 BUG #17932: Cannot select big bytea values(>500MB) PG Bug reporting form <noreply@postgresql.org>
2023-05-16 01:58 ` John Naylor <john.naylor@enterprisedb.com>
2023-05-18 07:23   ` duc hiep ha <haduchiep@googlemail.com>

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