Re: user authentication crash by Erik Luke (20-08-2001; 1.3kb)
"Thomas Yackel" <yackelt@ohsu.edu> writes:
I got the error: "Bad abstime external representation ''" when attempted to start psql as a particular user and the postmaster shutdown.
The problem, we discovered, is that this user had a carriage return contained within his password. Changing the password to remove the CR avoided the system shutdown.
Hmm. I can see how a linefeed in a password would create a problem (it
breaks the line-oriented formatting of the pg_pwd file). However, I
can't reproduce a postmaster crash here. Either I'm not testing the
right combination of circumstances, or current sources are more robust
about this than 7.1. That's not unlikely given that Bruce rewrote the
password-file-parsing code a couple months ago.
In any case it seems like it'd be a good idea to forbid nonprinting
characters in passwords. Comments anyone?
regards, tom lane
Import Notes
Reply to msg id not found: sbdfec8d.014@gwsmtp.ohsu.eduReference msg id not found: sbdfec8d.014@gwsmtp.ohsu.edu
when doing some works with views, I faced the following problem :
consider the following schema :
create table A (v1 int4,v2 int4);
create table B (v1 int4,v2 int4);
create view C as select v1,v2 from A union all select v1,v2 from B;
populate A and B with several thousands records
select v1 from c where v2=1000; give the following plan :
Subquery Scan c (cost=0.00..4544.12 rows=294912 width=8)
-> Append (cost=0.00..4544.12 rows=294912 width=8)
-> Subquery Scan *SELECT* 1 (cost=0.00..252.84 rows=16384 width=8)
-> Seq Scan on a (cost=0.00..252.84 rows=16384 width=8)
-> Subquery Scan *SELECT* 2 (cost=0.00..4291.28 rows=278528
width=8)
-> Seq Scan on b (cost=0.00..4291.28 rows=278528 width=8)
select v1 from a where v2=5 union all select v1 from b where v2=1000;
give the following plan :
Append (cost=0.00..217.88 rows=83 width=4)
-> Subquery Scan *SELECT* 1 (cost=0.00..2.02 rows=1 width=4)
-> Index Scan using idx1 on a (cost=0.00..2.02 rows=1 width=4)
-> Subquery Scan *SELECT* 2 (cost=0.00..215.86 rows=82 width=4)
-> Index Scan using idx2 on b (cost=0.00..215.86 rows=82 width=4)
Is there a way for the optimizer to move the view "where" clause in the
elementary union queries in order to use an index scan instead of the Seq
scan ?
I'm using 7.1.3
cyril
Import Notes
Reference msg id not found: sbdfec8d.014@gwsmtp.ohsu.edu
"Cyril VELTER" <cyril.velter@libertysurf.fr> writes:
Is there a way for the optimizer to move the view "where" clause in the
elementary union queries in order to use an index scan instead of the Seq
scan ?
This is on the "to look at" list. It's not immediately clear to me
whether there are any restrictions on when the system can safely make
such a transformation, nor whether there are cases where it would be
a pessimization rather than an optimization.
regards, tom lane