Обсуждение: How to add constraints without validating data.
Hi Gurus
Is there any way in postgreSQL to apply constraints forcefully without checking/validating Data ? It should validate only those records which comes after constraints are applied.
I need this help as data is already loaded in database but "ALTER TABLE" sql for adding CONSTRAINTS is taking enormous time.
Thanks for ideas/suggestion in Advance !!
Is there any way in postgreSQL to apply constraints forcefully without checking/validating Data ? It should validate only those records which comes after constraints are applied.
I need this help as data is already loaded in database but "ALTER TABLE" sql for adding CONSTRAINTS is taking enormous time.
Thanks for ideas/suggestion in Advance !!
--
Regards, Amit Jain Synechron Technologies Pvt. Ltd. 4th Floor, B Wing, Block 1.2, Embassy Techzone, Rajiv Gandhi Infotech Park, Hinjewadi Phase II, Pune 411 057. Phone : +91.20.40262000 Ext 2163 | Mobile:+91.9561298565 | VoIP : +1.732.415.0894 http://www.synechron.com MailTo: amitjain@synechron.com
On Thu, May 27, 2010 at 5:55 PM, Amit jain <amitjain@synechron.com> wrote: > Hi Gurus > > Is there any way in postgreSQL to apply constraints forcefully without > checking/validating Data ? It should validate only those records which comes > after constraints are applied. > > I need this help as data is already loaded in database but "ALTER TABLE" sql > for adding CONSTRAINTS is taking enormous time. > > Thanks for ideas/suggestion in Advance !! > > > -- > > Regards, > > Amit Jain > Synechron Technologies Pvt. Ltd. 4th Floor, B Wing, Block 1.2, Embassy > Techzone, > Rajiv Gandhi Infotech Park, Hinjewadi Phase II, Pune 411 057. > Phone : +91.20.40262000 Ext 2163 | Mobile:+91.9561298565 | VoIP : > +1.732.415.0894 > http://www.synechron.com MailTo: amitjain@synechron.com > > I don't think there's any method to do that. If you add a constraint using ALTER TABLE it will check existing data also. One option is you create a new table with the constraints and same column names then: insert into newtable values ( select * from oldtable) but again this will check for old data, but may be faster. -- Nilesh Govindarajan Facebook: nilesh.gr Twitter: nileshgr Website: www.itech7.com
You have to disable triggers.
Two options:
- Export table data, truncate table (if your table is fk source you will have a problem), add constraint and import exported data with --disable-triggers flag in pg_restore.
- Perhaps you could add manually triger via pg_trigger table in pg_catalog whith an insert into this table.
-----Original Message-----
From: Amit jain <amitjain@synechron.com>
To: pgsql-admin@postgresql.org <pgsql-admin@postgresql.org>
Subject: [ADMIN] How to add constraints without validating data.
Date: Thu, 27 May 2010 17:55:56 +0530
Hi Gurus
Is there any way in postgreSQL to apply constraints forcefully without checking/validating Data ? It should validate only those records which comes after constraints are applied.
I need this help as data is already loaded in database but "ALTER TABLE" sql for adding CONSTRAINTS is taking enormous time.
Thanks for ideas/suggestion in Advance !!
--
Two options:
- Export table data, truncate table (if your table is fk source you will have a problem), add constraint and import exported data with --disable-triggers flag in pg_restore.
- Perhaps you could add manually triger via pg_trigger table in pg_catalog whith an insert into this table.
-----Original Message-----
From: Amit jain <amitjain@synechron.com>
To: pgsql-admin@postgresql.org <pgsql-admin@postgresql.org>
Subject: [ADMIN] How to add constraints without validating data.
Date: Thu, 27 May 2010 17:55:56 +0530
Hi Gurus
Is there any way in postgreSQL to apply constraints forcefully without checking/validating Data ? It should validate only those records which comes after constraints are applied.
I need this help as data is already loaded in database but "ALTER TABLE" sql for adding CONSTRAINTS is taking enormous time.
Thanks for ideas/suggestion in Advance !!
--
Regards, Amit Jain Synechron Technologies Pvt. Ltd. 4th Floor, B Wing, Block 1.2, Embassy Techzone, Rajiv Gandhi Infotech Park, Hinjewadi Phase II, Pune 411 057. Phone : +91.20.40262000 Ext 2163 | Mobile:+91.9561298565 | VoIP : +1.732.415.0894 http://www.synechron.com MailTo: amitjain@synechron.com
On Thu, May 27, 2010 at 9:30 PM, Iñigo Martinez Lasala <imartinez@vectorsf.com> wrote: > You have to disable triggers. > > Two options: > > - Export table data, truncate table (if your table is fk source you will > have a problem), add constraint and import exported data with > --disable-triggers flag in pg_restore. > > - Perhaps you could add manually triger via pg_trigger table in pg_catalog > whith an insert into this table. > > -----Original Message----- > From: Amit jain <amitjain@synechron.com> > To: pgsql-admin@postgresql.org <pgsql-admin@postgresql.org> > Subject: [ADMIN] How to add constraints without validating data. > Date: Thu, 27 May 2010 17:55:56 +0530 > > Hi Gurus > > Is there any way in postgreSQL to apply constraints forcefully without > checking/validating Data ? It should validate only those records which comes > after constraints are applied. > > I need this help as data is already loaded in database but "ALTER TABLE" sql > for adding CONSTRAINTS is taking enormous time. > > Thanks for ideas/suggestion in Advance !! > > > -- > > Regards, > > Amit Jain > Synechron Technologies Pvt. Ltd. 4th Floor, B Wing, Block 1.2, Embassy > Techzone, > Rajiv Gandhi Infotech Park, Hinjewadi Phase II, Pune 411 057. > Phone : +91.20.40262000 Ext 2163 | Mobile:+91.9561298565 | VoIP : > +1.732.415.0894 > http://www.synechron.com MailTo: amitjain@synechron.com > > > > > How would disabling triggers help that ? He just wants to add constraints without loss of data. I don't think he has any triggers. -- Nilesh Govindarajan Facebook: nilesh.gr Twitter: nileshgr Website: www.itech7.com
Constraints are special triggers, but triggers anyway.
So, If you truncate the table, create the contraint and then restore with triggers disabled, it could be faster that create the contraint and wait until it checks all table data... or not... :)
-----Original Message-----
From: Nilesh Govindarajan <lists@itech7.com>
To: Iñigo Martinez Lasala <imartinez@vectorsf.com>
Cc: Amit jain <amitjain@synechron.com>, pgsql-admin@postgresql.org
Subject: Re: [ADMIN] How to add constraints without validating data.
Date: Thu, 27 May 2010 21:45:25 +0530
So, If you truncate the table, create the contraint and then restore with triggers disabled, it could be faster that create the contraint and wait until it checks all table data... or not... :)
-----Original Message-----
From: Nilesh Govindarajan <lists@itech7.com>
To: Iñigo Martinez Lasala <imartinez@vectorsf.com>
Cc: Amit jain <amitjain@synechron.com>, pgsql-admin@postgresql.org
Subject: Re: [ADMIN] How to add constraints without validating data.
Date: Thu, 27 May 2010 21:45:25 +0530
How would disabling triggers help that ? He just wants to add constraints without loss of data. I don't think he has any triggers.
On Thu, May 27, 2010 at 9:49 PM, Iñigo Martinez Lasala <imartinez@vectorsf.com> wrote: > Constraints are special triggers, but triggers anyway. > > So, If you truncate the table, create the contraint and then restore with > triggers disabled, it could be faster that create the contraint and wait > until it checks all table data... or not... :) > > > > -----Original Message----- > From: Nilesh Govindarajan <lists@itech7.com> > To: Iñigo Martinez Lasala <imartinez@vectorsf.com> > Cc: Amit jain <amitjain@synechron.com>, pgsql-admin@postgresql.org > Subject: Re: [ADMIN] How to add constraints without validating data. > Date: Thu, 27 May 2010 21:45:25 +0530 > > How would disabling triggers help that ? He just wants to add > constraints without loss of data. I don't think he has any triggers. > > > I agree constraints are triggers. But as far as I know, truncating table doesn't disable the constraints. Its same as deleteing all rows and then altering the table. In that manner, even my solution would be appropriate because it creates a duplicate table with the constraints. Whatever be the method, I don't think its possible to avoid the constraints. Correct me if I'm wrong. -- Nilesh Govindarajan Facebook: nilesh.gr Twitter: nileshgr Website: www.itech7.com
Why don't you use a partition? Create another table that inherits from the table and add your new constraints to the new table. On Thursday 27 May 2010 19:32:33 Nilesh Govindarajan wrote: > On Thu, May 27, 2010 at 9:49 PM, Iñigo Martinez Lasala > > <imartinez@vectorsf.com> wrote: > > Constraints are special triggers, but triggers anyway. > > > > So, If you truncate the table, create the contraint and then restore with > > triggers disabled, it could be faster that create the contraint and wait > > until it checks all table data... or not... :) > > > > How would disabling triggers help that ? He just wants to add > > constraints without loss of data. I don't think he has any triggers. > > I agree constraints are triggers. But as far as I know, truncating > table doesn't disable the constraints. > Its same as deleteing all rows and then altering the table. > In that manner, even my solution would be appropriate because it > creates a duplicate table with the constraints. > Whatever be the method, I don't think its possible to avoid the > constraints. Correct me if I'm wrong. -- Robert Voinea <robert (dot) voinea (at) topex (dot) ro> Software Developer Phone: +40 21 408 38 00 / ext. 343 Fax: +40 21 408 38 08 Local time: GMT+2 http://www.topex.ro