Regarding varchar max length in postgres

On 10/5/18 8:18 AM, Durgamahesh Manne wrote:

Hi

please let me know the max length of varchar  & text in postgres

https://www.postgresql.org/docs/10/static/datatype-character.html

Regards

Durgamahesh Manne

--
Adrian Klaver
adrian.klaver@aklaver.com

On Fri, Oct 5, 2018 at 8:55 PM Adrian Klaver <adrian.klaver@aklaver.com>
wrote:

On 10/5/18 8:18 AM, Durgamahesh Manne wrote:

Hi

please let me know the max length of varchar & text in postgres

https://www.postgresql.org/docs/10/static/datatype-character.html

Regards

Durgamahesh Manne

--
Adrian Klaver
adrian.klaver@aklaver.com

Hi

Thank you for this information

as per the postgresql documentation

If character varying is used without length specifier, the type accepts
strings of any size

but varchar does not accept more than this

On Mon, Oct 15, 2018 at 2:32 PM Durgamahesh Manne <maheshpostgres9@gmail.com>
wrote:

On Fri, Oct 5, 2018 at 8:55 PM Adrian Klaver <adrian.klaver@aklaver.com>
wrote:

On 10/5/18 8:18 AM, Durgamahesh Manne wrote:

Hi

please let me know the max length of varchar & text in postgres

https://www.postgresql.org/docs/10/static/datatype-character.html

Regards

Durgamahesh Manne

--
Adrian Klaver
adrian.klaver@aklaver.com

Hi

Thank you for this information

as per the postgresql documentation please ignore incomplete message i
mailed to respected community members

If character varying is used without length specifier, the type accepts
strings of any size

but varchar does not accept more than this 10485760 value

create table test(id serial primary key, str varchar(10485761));

ERROR: length for type varchar cannot exceed 10485760

Durgamahesh Manne schrieb am 15.10.2018 um 11:05:

On 10/5/18 8:18 AM, Durgamahesh Manne wrote:

Hi

please let me know the max length of varchar  & text in postgres

https://www.postgresql.org/docs/10/static/datatype-character.html

 Hi 

Thank you for this information

as per the postgresql documentation   please ignore incomplete message i mailed to respected community members 

 If |character varying |is used without length specifier, the type accepts strings of any size 

but varchar does not accept more than this 10485760 value

   create table test(id serial primary key, str varchar(10485761));

     ERROR: length for type varchar cannot exceed 10485760

Further down on that page the overall limit is documented:

In any case, the longest possible character string that can be stored is about 1 GB

So the part that you quoted implicitly means "accepts strings of any size - up to the maximum of 1GB"
Maybe it makes sense to make that clearer at that point.

Regards
Thomas

On Mon, Oct 15, 2018 at 2:35 PM Durgamahesh Manne <maheshpostgres9@gmail.com>
wrote:

On Mon, Oct 15, 2018 at 2:32 PM Durgamahesh Manne <
maheshpostgres9@gmail.com> wrote:

On Fri, Oct 5, 2018 at 8:55 PM Adrian Klaver <adrian.klaver@aklaver.com>
wrote:

On 10/5/18 8:18 AM, Durgamahesh Manne wrote:

Hi

please let me know the max length of varchar & text in postgres

https://www.postgresql.org/docs/10/static/datatype-character.html

Regards

Durgamahesh Manne

--
Adrian Klaver
adrian.klaver@aklaver.com

Hi

Thank you for this information

((((as per the postgresql documentation

If character varying is used without length specifier, the type accepts
strings of any size

but varchar does not accept more than this ))))

On Mon, Oct 15, 2018 at 2:42 PM Durgamahesh Manne <maheshpostgres9@gmail.com>
wrote:

On Mon, Oct 15, 2018 at 2:35 PM Durgamahesh Manne <
maheshpostgres9@gmail.com> wrote:

On Mon, Oct 15, 2018 at 2:32 PM Durgamahesh Manne <
maheshpostgres9@gmail.com> wrote:

On Fri, Oct 5, 2018 at 8:55 PM Adrian Klaver <adrian.klaver@aklaver.com>
wrote:

On 10/5/18 8:18 AM, Durgamahesh Manne wrote:

Hi

please let me know the max length of varchar & text in postgres

https://www.postgresql.org/docs/10/static/datatype-character.html

Regards

Durgamahesh Manne

--
Adrian Klaver
adrian.klaver@aklaver.com

Hi

Thank you for this information

((((as per the postgresql documentation

If character varying is used without length specifier, the type accepts
strings of any size

but varchar does not accept more than this ))))

as per the postgresql documentation please ignore incomplete above
message i mailed to respected community members

If character varying is used without length specifier, the type
accepts strings of any size

but varchar does not accept more than this 10485760 value

create table test(id serial primary key, str varchar(10485761));

ERROR: length for type varchar cannot exceed 10485760

as thomas said that

Further down on that page the overall limit is documented:

In any case, the longest possible character string that can be stored
is about 1 GB

So the part that you quoted implicitly means "accepts strings of any size
- up to the maximum of 1GB"
Maybe it makes sense to make that clearer at that point.

was there any specific reason that you have given max length for varchar is
limited to 10485760 value?

why you have not given max length for varchar is unlimited like text
datatype ?

character varying(*n*), varchar(*n*)variable-length with limit
character(*n*), char(*n*)fixed-length, blank padded
textvariable unlimited length

Regards

Durgamahesh Manne wrote:

was there any specific reason that you have given max length for varchar is limited to 10485760 value?

why you have not given max length for varchar is unlimited like text datatype ?

character varying(n), varchar(n)variable-length with limit
character(n), char(n)fixed-length, blank padded
textvariable unlimited length

The data type "text" has the same size limit of 1GB.
"character varying" (without type modifier) and "text" are pretty much
identical.

Since data of these types are loaded into memory when you read them
from or write them to the database, you usually start having problems
long before you reach that limit.

If you want to store huge text files, either store them outside the
database or use Large Objects, which can be read and written in chunks.

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com

Durgamahesh Manne schrieb am 15.10.2018 um 11:18:

was there any specific reason that you have given max length for varchar is limited to 10485760 value?

why you have not given max length for varchar is unlimited like text datatype ?

|character varying(/|n|/)|, |varchar(/|n|/)|variable-length with limit 
|character(/|n|/)|, |char(/|n|/)|fixed-length, blank padded
|text|variable unlimited length

It "text" type is a "character string" just like all the other character types and thus is also limited to 1GB

"text", "varchar", "character varying" and "character" are all identical in how they are stored and processed.

Thomas

On Mon, Oct 15, 2018 at 3:11 PM Thomas Kellerer <spam_eater@gmx.net> wrote:

Durgamahesh Manne <maheshpostgres9@gmail.com> writes:

If character varying is used without length specifier, the type
accepts strings of any size
but varchar does not accept more than this 10485760 value

You're confusing the size of string that can be stored with the
largest value accepted for "n" in "varchar(n)". This is documented,
in the same place that people have been pointing you to:

In any case, the longest possible character string that can be stored
is about 1 GB. (The maximum value that will be allowed for n in the
---------------------------------------------------
data type declaration is less than that. It wouldn't be useful to
----------------------------------------
change this because with multibyte character encodings the number of
characters and bytes can be quite different. If you desire to store
long strings with no specific upper limit, use text or character
varying without a length specifier, rather than making up an arbitrary
length limit.)

As you found out, the limit for "n" is ~ 10 million.

In principle, we could have allowed it to be as much as 1Gb divided by
the maximum character length of the database's encoding, but it did
not seem like a great idea for the limit to be encoding-dependent.

As the last sentence in the doc paragraph points out, the preferred
thing to do if you just want to allow very long strings is to leave
off "(n)" altogether.

The subtext here, which maybe we ought to state in a more in-your-face
way, is that if you use char(N) or varchar(N) without a concrete
application-driven reason why N has to be that particular value,
no more or less, then You're Doing It Wrong. Artificially-chosen
column width limits are a bad idea left over from the days of
punched cards. The reason the limit on N is much smaller than it
could theoretically be is that column declarations with very large
N are, without exception, violations of this principle.

regards, tom lane

On Mon, Oct 15, 2018 at 7:54 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:

Durgamahesh Manne <maheshpostgres9@gmail.com> writes:

If character varying is used without length specifier, the type
accepts strings of any size
but varchar does not accept more than this 10485760 value

You're confusing the size of string that can be stored with the
largest value accepted for "n" in "varchar(n)". This is documented,
in the same place that people have been pointing you to:

In any case, the longest possible character string that can be stored
is about 1 GB. (The maximum value that will be allowed for n in the
---------------------------------------------------
data type declaration is less than that. It wouldn't be useful to
----------------------------------------
change this because with multibyte character encodings the number of
characters and bytes can be quite different. If you desire to store
long strings with no specific upper limit, use text or character
varying without a length specifier, rather than making up an arbitrary
length limit.)

As you found out, the limit for "n" is ~ 10 million.

In principle, we could have allowed it to be as much as 1Gb divided by
the maximum character length of the database's encoding, but it did
not seem like a great idea for the limit to be encoding-dependent.

As the last sentence in the doc paragraph points out, the preferred
thing to do if you just want to allow very long strings is to leave
off "(n)" altogether.

The subtext here, which maybe we ought to state in a more in-your-face
way, is that if you use char(N) or varchar(N) without a concrete
application-driven reason why N has to be that particular value,
no more or less, then You're Doing It Wrong. Artificially-chosen
column width limits are a bad idea left over from the days of
punched cards. The reason the limit on N is much smaller than it
could theoretically be is that column declarations with very large
N are, without exception, violations of this principle.

regards, tom lane

Hi sir

If character varying is used without length specifier, the datatype
accepts strings of any size up to maximum of 1GB as i found this info

in pgdg doc

I have not used this max length 10485760 value at varchar in table of db
as well as i have not confused about this maximium length of the string for
varchar upto 1GB

I have used this column datatype varchar with out using any limit

I have checked with more than above value by creating table test
with create table test(id serial primary key, str varchar(10485761)) as an
example

ERROR: length for type varchar cannot exceed 10485760

text variable unlimited length
character varying(*n*), varchar(*n*) variable-length with limit
as per the documented text is with unlimited length and varchar variable
length is with limit 1GB

So i need unlimited length data type for required column of the table for
storing the large values

is there any issue to use unlimited length datatype text for the required
column of the table instead of using varchar ?

Regards

Durgamahesh Manne

On Mon, Oct 15, 2018 at 8:24 AM Durgamahesh Manne <maheshpostgres9@gmail.com>
wrote:

So i need unlimited length data type for required column of the table for
storing the large values
is there any issue to use unlimited length datatype text for the
required column of the table instead of using varchar ?

Between the two you should use the "text" data type for those columns. You
will need to describe your use case in more detail if you want input as to
whether you need to use the large object API instead.

The database cannot store an unlimited amount of data in a single
row+column (cell) - you will still encounter a physical limit to the number
of bytes able to be stored in a single cell when using text.

David J.

On Mon, Oct 15, 2018 at 9:07 PM David G. Johnston <
david.g.johnston@gmail.com> wrote:

On Mon, Oct 15, 2018 at 8:24 AM Durgamahesh Manne <
maheshpostgres9@gmail.com> wrote:

So i need unlimited length data type for required column of the table for
storing the large values
is there any issue to use unlimited length datatype text for the
required column of the table instead of using varchar ?

Between the two you should use the "text" data type for those columns.
You will need to describe your use case in more detail if you want input as
to whether you need to use the large object API instead.

The database cannot store an unlimited amount of data in a single
row+column (cell) - you will still encounter a physical limit to the number
of bytes able to be stored in a single cell when using text.

David J.

Hi sir

i need to store more values on required column of the table by using text
than varchar

you said that physical limit needs to be stored values in column of the
table

text variable unlimited length

Thank you for this valuable information

PostgreSQL is always no 1 world s leading open source RDBMS

I request you all community members to provide built in bdr v3 version
replication for public as multimaster replication is on high priority
against other dbms

On 10/15/18 8:56 AM, Durgamahesh Manne wrote:

On Mon, Oct 15, 2018 at 9:07 PM David G. Johnston
<david.g.johnston@gmail.com <mailto:david.g.johnston@gmail.com>> wrote:

On Mon, Oct 15, 2018 at 8:24 AM Durgamahesh Manne
<maheshpostgres9@gmail.com <mailto:maheshpostgres9@gmail.com>> wrote:

So i need unlimited length data type for required column of the
table for storing the large values
is there any issue to use unlimited length datatype  text  for
the required column of the table instead of using varchar ?

Between the two you should use the "text" data type for those
columns.  You will need to describe your use case in more detail if
you want input as to whether you need to use the large object API
instead.

The database cannot store an unlimited amount of data in a single
row+column (cell) - you will still encounter a physical limit to the
number of bytes able to be stored in a single cell when using text.

David J.

Hi sir

 i need to store more values on required column of the table by using
text  than varchar

you said that physical limit needs to be stored values  in column of the
table

|text| variable unlimited length

There are two limits at work here. n in varchar(n) and char(n) is the
number of characters that can be stored. Text does not have the ability
to limit the characters on declaration. In the special case of varchar
(no n declared) it is equal to text. All the character types(varchar,
char, text) have a storage limit of 1GB per field. This storage value is
not necessarily a one to one relationship to n as the encoding for the
string maybe a multibyte one and a character may occupy multiple bytes.

ype
Thank you for this valuable information

 PostgreSQL is always no 1 world s leading open source  RDBMS

 I request you all community members to provide built in bdr v3 version
replication for public as multimaster replication is on high priority
against other dbms

--
Adrian Klaver
adrian.klaver@aklaver.com

On 10/15/18 8:56 AM, Durgamahesh Manne wrote:

 I request you all community members to provide built in bdr v3 version
replication for public as multimaster replication is on high priority
against other dbms

BDR v3 is third party extension from 2ndQuadrant, it is not community
code. Elements of it have found there into the community code as logical
replication, but that is as far as it has gotten. You will need to take
this up with 2ndQuadrant.

--
Adrian Klaver
adrian.klaver@aklaver.com

On Mon, Oct 15, 2018 at 9:52 PM Adrian Klaver <adrian.klaver@aklaver.com>
wrote:

On 10/15/18 8:56 AM, Durgamahesh Manne wrote:

I request you all community members to provide built in bdr v3 version
replication for public as multimaster replication is on high priority
against other dbms

BDR v3 is third party extension from 2ndQuadrant, it is not community
code. Elements of it have found there into the community code as logical
replication, but that is as far as it has gotten. You will need to take
this up with 2ndQuadrant.

--
Adrian Klaver
adrian.klaver@aklaver.com

Thank you for this information sir