Thread: configure datatype name > 31?

Is there a way to configure PostgreSQL to make the name field larger?

The name datatype, which is used for these two columns in these system
tables:

    pg_database.datname
    pg_shadow.usename

is a 31 character field.  That seems awfully low.  For instance, what if I'm
silly enough to want to make a database named:

    customer_GUID

where GUID is something like:

    0ff7d0cc-7394-4b15-a28e-7018b1056f9c

You can imagine I have many customers, each with their own database; since I
use a guid to distinguish the customers, it makes most sense to me to use a
guid to distinguish their databases.

Since GUIDs (in that form at least) are 36 characters, I'm already SOL.  I
can condense the data, but I'd really much rather just use it like it is.

SQL Server 2000, for example, uses nvarchar(256) for the sysname field,
which seems to perform a similar function.

Thanks,

// mark

"Mark McEahern" <marklists@mceahern.com> writes:
> Is there a way to configure PostgreSQL to make the name field larger?

Edit src/include/postgres_ext.h to change NAMEDATALEN (keep it a
multiple of 4).  Build, install, initdb.

In current releases there are client-side dependencies on NAMEDATALEN,
so you should take care to recompile *everything*.  We are working to
remove all dependencies on NAMEDATALEN in the standard clients and
client libraries for 7.3, though.

According to recent tests there's a measurable performance hit for
large values of NAMEDATALEN, so I wouldn't recommend making it bigger
than about 100 ...

            regards, tom lane