Re: need an information on PostgreSQL

On Thu, 9 Nov 2000, Denis A. Doroshenko wrote:

> Hello,
>
> i'm a newbie to pgsql (and SQL as well) so please be patient :-)
>
> first, i would like to know all limitations (or call it parameters) of
> PostgreSQL 7 (i use 7.0.2). that includes for example, number of
> columns in a row, number of rows in a table, number of triggers,
> indexes per table. the only limitations i've seen in various sources is
> a row size (currently -- 8k) and indexning length of text (something
> about 2k). i like many things in PostgreSQL and such information would
> help me to evaluate the possibility to use it in bigger projects...

All of the below IIRC... :)
The total row size must be under 8k, so that limits the number columns
to a row by minimum size requirements (you can't fit 10k ints for
example), but otherwise I don't know of anything for columns.
I don't know of a number of row in table limit, the system breaks
up heap files to get around filesystem limits, probably disk space and
performance related (make sure you have indexes and are using queries
that use them). The length of views and procedure text is limited
since a format of those need to fit into a database row. The
text length limit for indexes is approximately 2700 bytes and that
might be the procedure length.

> does PoestgreSQL support stored procedures? and will it do, if
> it isn't. i could not find any reference on this in docs/htmls...
> BTW, about "will it support", is there some roadmap for PostgreSQL?
> i've looked at TODO, but hmm :-) it's more detailed than i need...
Sort of, it has user defined functions, but pl functions in 7.0
can't really intelligibly return sets of rows (at least without
jumping through hoops). But functions that act on data are there.
Also in 7.0, functions don't take null parameters very well.

> does PostgreSQL support object naming as "[[[server.]dbname.]
> owner.]objectname"?
Not yet. Schemas have been talked about, but I haven't heard to much
about supporting server.dbname.

> how could i restrict a user from looking what tables are in database
> as well as what their structures are. i know i could restrict
> select/update/alter/delete/whatever, but can i hide the tables from
> a user? also, can PostgreSQL hide some particular columns from user?
Not really. Also in 7.0 you can't prevent someone who can connect
from creating database objects.

Some of these are fixed or changed in current sources and will be part
of 7.1.