Hi David,
Hi,
I am trying to create partitions on the table which have around 2BIL records 
and users will always look for the "name", its not possible to create a 
partition with a list, so we are trying to create a partition-based first 
letter of the name column. name column has a combination of alpha numeric 
values.


> postgres=# select chr(ascii('z')+1) ;
> chr
> -----
> {
> (1 row)

I tried as below, I'm able to create a partition table for 'Z', but it's not 
identifying partition table. 

postgres=# select chr(ascii('Z')+1) ;
chr
-----
[
(1 row)
 create table mytable_z of mytable  for values from ('Z') to ('Z[');CREATE 
TABLE 
insert into mytable  values(4,'ZAR83NB');

ERROR: no partition of relation "mytable" found for rowDETAIL: Partition key of 
the failing row contains (name) = (ZAR83NB).SQL state: 23514




    On Friday, May 21, 2021, 01:24:13 AM PDT, David Rowley 
<dgrowle...@gmail.com> wrote:  
 
 On Fri, 21 May 2021 at 19:02, Nagaraj Raj <nagaraj...@yahoo.com> wrote:
> then what would be the range of Z
> FROM (Z) to (?) ;

postgres=# select chr(ascii('z')+1) ;
 chr
-----
 {
(1 row)


> same way for 9

postgres=# select chr(ascii('9')+1) ;
 chr
-----
 :
(1 row)

https://en.wikipedia.org/wiki/ASCII

You can also use MINVALUE and MAXVALUE to mean unbounded at either end
of the range.

But is there a particular need that you want to partition this way? It
seems like it might be a bit painful to maintain, especially if you're
not limiting yourself to ASCII or ANSI characters.

You might want to consider HASH partitioning if you're just looking
for a way to keep your tables and indexes to a more manageable size.
You've not really mentioned your use case here, so it's hard to give
any advice.

There are more details about partitioning in
https://www.postgresql.org/docs/current/ddl-partitioning.html

David


  

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