Re: do postgresql this job for me ? (firebird user) - Mailing list pgsql-general

mnavahan wrote:

> 1.have postgresql support online change of tables ?
>  for example i have over 400 table in db with many relation :
>   A: if i dont any user connect to table RR (but many user connect to other
> tables) can in online Db i change   table RR ?

Yes.

>   B: if table A have FK to B can edit table  B for example Add field ?

Yes, though if users are active on tables A or B your ALTER command will
be delayed until their transactions commit or roll back.

> have any documented information for change table when online
> (book,note,.....) of up ?

I strongly recommend reading the whole PostgreSQL manual. It's excellent
 - well written, covers the database's features and usage very well, and
will teach you a lot about SQL in general as well.

> 2. postgresql do any index corruption when memory low or same problem ?

No, nor if it runs out of disk space or if the database crashes. It's
not meant to, anyway, and is designed to avoid it happening.

There have been index corruption reports here, but most seem to boil
down to file system issues, disk issues, RAID controller problems, and
antivirus software interference.

The only thing that's likely to make things go pear-shaped is if the
postmaster is forcibly killed ( kill -9 ) while the worker children are
running, then the postmaster is re-started. This will never happen if
you properly configure the Linux virtual memory manager - in particular,
disable vm overcommit to prevent the OOM killer from running.

> 3. postgresql support recursive call in stored procedure and in depth
> recursive have good performance?

Yes to all of the above.

> 4.have any way port firebird stored procedure to postgresql ?

If firebird stored procedures are written in ordinary SQL, or a quite
SQL-like language (akin to Oracle's PL/SQL) then porting to PostgreSQL's
PL/PgSQL shouldn't be too hard.

I don't know of any automatic tools, but I've never had cause to look.

> 5.postgresql support Sql in stored procedure via sting (i have one string
> contain sql can execute it and get result ?)

Yes - see the EXECUTE command in PL/SQL.

> 6.how performance of temp table (is in memory and then ultra fast ?)

Temp tables are allocated on disk. However, they get the normal benefits
of PostgreSQL's caching, and tend to be very fast. You can put them in a
tablespace on a RAM disk or the like if you want, though.

I don't know if writes to temp tables go through the WAL or not, nor if
they're opened O_SYNC for synchronous writes.

--
Craig Ringer