Re: Does PostgreSQL check database integrity at startup?
>There should be a "catalog" that point where tables are stored in physical files...
Here is the query that gives you that information.SELECT c.oid,
n.nspname as schema,
c.relname as table,
(SELECT oid FROM pg_database WHERE datname = current_database() ) as db_dir,
c.relfilenode as filename
FROM pg_class c
JOIN pg_namespace n ON (n.oid = c.relnamespace)
WHERE relname NOT LIKE 'pg_%'
AND relname NOT LIKE 'information%'
AND relname NOT LIKE 'sql_%'
AND relkind = 'r'
ORDER BY 2, relname;
On Fri, Dec 29, 2017 at 8:13 PM, Stephen Frost <sfrost@snowman.net> wrote:
Greetings,
* Edson Carlos Ericksson Richter (richter@simkorp.com.br) wrote:
> There should be a "catalog" that point where tables are stored in physical
> files (I think, at least, because at some point PostgreSQL need to know from
> where to read the data).
Yes, it's pg_class. Specifically, the relfilenode.
> Based on information from this catalog, would I have a tool (perhaps, a C
> function) that check that data is really there?
You could write such a function, but it wouldn't be able to be general
purpose as a zero-byte file is, in fact, a valid file. You could just
as easily do a 'select 1 from table limit 1;' and make sure that you get
back a successful, single-row, result, if you wish to verify that certain
tables in your database always have at least 1 row.
Thanks!
Stephen
--
Melvin Davidson
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.
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