RE: [CDBI] Class::DBI vs DBIx::Class

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From: Dmitri Bichko
Subject: RE: [CDBI] Class::DBI vs DBIx::Class
Date: 18:20 on 18 Jan 2006
If 24/7 uptime is necessary and a few failed queries are not acceptable,
I believe the Right Thing to do is run the database as a cluster: bring
up the new schema as a new node, transfer users to it and then change
the existing installation.  Admittedly, I don't have much experience
with this sort of thing.

Generally, I don't know how well any database can be expected to deal
with schema changes during the lifetime of a transaction.  What if a
query is actually scanning that index as you are dropping it?

On the other hand, I've had a lot of problems with postgres prepared
statements and how the planner handles them.  For me at least, the
possibility that the planner will do better on complicated queries
knowing the actual bind values (rare big wins) outweighed the time spent
reparsing the queries on every execute (frequent small losses), so I
just turn them off.  YMMV of course.

Dmitri


> -----Original Message-----
> From: classdbi-bounces@xxxxx.xxxxxxxxxxxxxxxx.xxx=20
> [mailto:classdbi-bounces@xxxxx.xxxxxxxxxxxxxxxx.xxx] On=20
> Behalf Of John Siracusa
> Sent: Wednesday, January 18, 2006 1:07 PM
> To: Class::DBI
> Subject: Re: [CDBI] Class::DBI vs DBIx::Class
>=20
>=20
> On 1/18/06, Dmitri Bichko <dbichko@xxxxxxxxxx.xxx> wrote:
> >> Maybe...I'll try it.  But it won't help in a web server=20
> environment=20
> >> because of the obvious race.
> >=20
> > How often do you have schema changes in a running=20
> application, anyway?=20
> > Seems a little sketchy to begin with.
>=20
> In a 24/7 webapp, you either never change the schema or you=20
> do it while it's running.  Both are preferable to any=20
> downtime.  Also, a "schema change" can be as simple as adding=20
> or dropping an index.  "Sketchy" or not, sometimes things=20
> like this are necessary.
>=20
> -John
>=20
>=20
>=20
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>=20
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[CDBI] Class::DBI vs DBIx::Class
David Lloyd 00:29 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Matt S Trout 01:18 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Tim Bunce 10:04 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Tim Bunce 00:15 on 28 Feb 2006

Old announce thread
Matt S Trout 15:29 on 28 Feb 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Brad Bowman 11:07 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
yoorobot 15:14 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Matt S Trout 16:15 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Christopher H. Laco 16:10 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Perrin Harkins 16:42 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Ryan Tate 18:30 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Matt S Trout 01:27 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Matt S Trout 18:40 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Perrin Harkins 18:44 on 17 Jan 2006

RE: [CDBI] Class::DBI vs DBIx::Class
Dmitri Bichko 16:22 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
John Siracusa 16:43 on 18 Jan 2006

RE: [CDBI] Class::DBI vs DBIx::Class
Dmitri Bichko 17:49 on 18 Jan 2006

RE: [CDBI] Class::DBI vs DBIx::Class
Perrin Harkins 18:03 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
John Siracusa 18:05 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
John Siracusa 18:06 on 18 Jan 2006

RE: [CDBI] Class::DBI vs DBIx::Class
Dmitri Bichko 18:20 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Matt S Trout 19:00 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Simon Wilcox 19:16 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Perrin Harkins 20:30 on 17 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Tim Bunce 00:56 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
John Siracusa 01:12 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Tim Bunce 11:36 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
John Siracusa 12:37 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Matt S Trout 01:21 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Tim Bunce 11:37 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Tim Bunce 23:43 on 18 Jan 2006

Re: [CDBI] Class::DBI vs DBIx::Class
Ryan Tate 23:57 on 18 Jan 2006

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