Thread: why the DB file size does not reduce when 'delete' the data in DB?
I had deleted a very large number of records out of my SQL table in order to decrease the harddisk space. But after I use command 'ls -l /usr/local/pgsql/data/base/', it is found that the size of concerning files do not reduce due to the effect of 'delete' SQL command. What should I do if I would like to decrease the harddisk space? I am looking forward to your response. Thank you very much for any help. - Jaruwan
Re: [HACKERS] why the DB file size does not reduce when 'delete' the data in DB?
From
Hannu Krosing
Date:
Jaruwan Laongmal wrote: > I had deleted a very large number of records out of my SQL table in order to > decrease the harddisk space. But after I use command 'ls -l > /usr/local/pgsql/data/base/', it is found that the size of concerning files > do not reduce due to the effect of 'delete' SQL command. What should I do > if I would like to decrease the harddisk space? Run the command VACUUM; This will do the actual removal of deleted records. DELETE just marks them as deleted > I am looking forward to your response. Thank you very much for any help. > - > Jaruwan
Re: [HACKERS] why the DB file size does not reduce when 'delete' the data in DB?
From
Thomas Lockhart
Date:
> I had deleted a very large number of records out of my SQL table in order to > decrease the harddisk space. But after I use command 'ls -l > /usr/local/pgsql/data/base/', it is found that the size of concerning files > do not reduce due to the effect of 'delete' SQL command. What should I do > if I would like to decrease the harddisk space? Run "vacuum" from SQL or "vacuumdb" from the command line. Tables will be reduced in size, though currently indices are not. - Thomas