a couple of newbie question - deferrable, varchar vs text, 2 dbs

Started by Sergei Shelukhinabout 19 years ago3 messagesgeneral
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#1Sergei Shelukhin
realgeek@gmail.com

1) Do I understand it correctly that cross database queries are not
possible? Two dbs on the same server are used in this case.

2) What's the difference between unlimited length varchar and text
columns? I am mostly interested in performance, namely = 'blah' and
like '%blah%' queries over these column types.

3) Will adding "deferrable" to FKs that reference very large tables
speed up insert performance for individual inserts? for multiple
inserts within a single transaction?

Thanks ;)

#2Peter Eisentraut
peter_e@gmx.net
In reply to: Sergei Shelukhin (#1)
Re: a couple of newbie question - deferrable, varchar vs text, 2 dbs

Sergei Shelukhin wrote:

1) Do I understand it correctly that cross database queries are not
possible?

Yes.

2) What's the difference between unlimited length varchar and text
columns?

Mostly only the spelling.

3) Will adding "deferrable" to FKs that reference very large tables
speed up insert performance for individual inserts? for multiple
inserts within a single transaction?

I think you can answer that yourself with a quick test.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

#3Sergei Shelukhin
realgeek@gmail.com
In reply to: Peter Eisentraut (#2)
Re: a couple of newbie question - deferrable, varchar vs text, 2 dbs

Thanks :)
As for pt3, I don't have the database I will use yet so it's hard to
test :(