Обсуждение: Monitoring database for changes - backup purposes
Hi, I have a query about a backup policy that I wish to implement. Currently, we are running a PostgreSQL server with a very large database on it. The database consists of a core of read-only tables, with tables created by the users going by default into the user's own schemas. For backup purposes, I have a script that uses pg_dump to create dumps of the individual user schemas. However, this is mainly a read-only database and information is added or updated only rarely. What I really need is a method of monitoring the database, such that my backup script will only back any one schema up if it has changed since it was last backed up. Is there any way to do this? Is there a checksum function or something that I could use? Thanks, Chris -- Chris Jewell, BSc(Hons), BVSc, MRCVS Dept of Maths and Statistics Fylde College Lancaster University Lancaster Lancs LA1 4YF
On Friday 14 October 2005 06:19, Chris Jewell wrote: > Hi, > > I have a query about a backup policy that I wish to implement. > Currently, we are running a PostgreSQL server with a very large database > on it. The database consists of a core of read-only tables, with tables > created by the users going by default into the user's own schemas. For > backup purposes, I have a script that uses pg_dump to create dumps of > the individual user schemas. However, this is mainly a read-only > database and information is added or updated only rarely. What I really > need is a method of monitoring the database, such that my backup script > will only back any one schema up if it has changed since it was last > backed up. Is there any way to do this? Is there a checksum function > or something that I could use? No there is not, but would a diff -q be sufficient for your needs ? > > Thanks, > > Chris -- Darcy Buskermolen Wavefire Technologies Corp. http://www.wavefire.com ph: 250.717.0200 fx: 250.763.1759
Hi, Yes, diff would work and is my current plan, but it requires me to perform the backup first. What I needed really was a system by which a backup would only be run if there was something that needed backing up. Thanks anyway, Chris -- Chris Jewell, BSc(Hons), BVSc, MRCVS Dept of Maths and Statistics Fylde College Lancaster University Lancaster Lancs LA1 4YF Darcy Buskermolen wrote: >On Friday 14 October 2005 06:19, Chris Jewell wrote: > > >>Hi, >> >>I have a query about a backup policy that I wish to implement. >>Currently, we are running a PostgreSQL server with a very large database >>on it. The database consists of a core of read-only tables, with tables >>created by the users going by default into the user's own schemas. For >>backup purposes, I have a script that uses pg_dump to create dumps of >>the individual user schemas. However, this is mainly a read-only >>database and information is added or updated only rarely. What I really >>need is a method of monitoring the database, such that my backup script >>will only back any one schema up if it has changed since it was last >>backed up. Is there any way to do this? Is there a checksum function >>or something that I could use? >> >> > >No there is not, but would a diff -q be sufficient for your needs ? > > > > >>Thanks, >> >>Chris >> >> > > >
On Fri, Oct 14, 2005 at 07:29:31PM +0100, Chris Jewell wrote: > Hi, > > Yes, diff would work and is my current plan, but it requires me to > perform the backup first. What I needed really was a system by which a > backup would only be run if there was something that needed backing up. I believe he meant diffing the files that store the tables. Another possibility that I think would work would be checking the last-modified timestamp of all the files in a schema. Though the easiest way to do that is probably to build a list of any files that have changed since the last backup and then figure out what schemas they're in. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
Chris, If you have a JDBC driver for pgsql, you can use SchemaCrawler. https://sourceforge.net/project/showfiles.php?group_id=148383 SchemaCrawler is a free, open source tool that can produce database schema metadata and/ or data output in a diff-able format. Sualeh. Chris Jewell wrote: > Hi, > > Yes, diff would work and is my current plan, but it requires me to > perform the backup first. What I needed really was a system by which a > backup would only be run if there was something that needed backing up. > > Thanks anyway, > > Chris > > -- > Chris Jewell, BSc(Hons), BVSc, MRCVS > Dept of Maths and Statistics > Fylde College > Lancaster University > Lancaster > Lancs > LA1 4YF > > > > Darcy Buskermolen wrote: > > >On Friday 14 October 2005 06:19, Chris Jewell wrote: > > > > > >>Hi, > >> > >>I have a query about a backup policy that I wish to implement. > >>Currently, we are running a PostgreSQL server with a very large database > >>on it. The database consists of a core of read-only tables, with tables > >>created by the users going by default into the user's own schemas. For > >>backup purposes, I have a script that uses pg_dump to create dumps of > >>the individual user schemas. However, this is mainly a read-only > >>database and information is added or updated only rarely. What I really > >>need is a method of monitoring the database, such that my backup script > >>will only back any one schema up if it has changed since it was last > >>backed up. Is there any way to do this? Is there a checksum function > >>or something that I could use? > >> > >> > > > >No there is not, but would a diff -q be sufficient for your needs ? > > > > > > > > > >>Thanks, > >> > >>Chris > >> > >> > > > > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq