Thread: size of a table on postgresql
| Hello, The following is the procedure to calculate the disk space occupied by postgresql from a flat file. In this I didn't understood some terms 24 bytes: each row header (approximate) |
aravind chandu wrote: > Hello, > > The following is the procedure to calculate the disk space > occupied by postgresql from a flat file. > > In this I didn't understood some terms > > 24 bytes: each row header (approximate) > 24 bytes: one int field and one text field > + 4 bytes: pointer on page to tuple > > here row header is taken as 24 bytes and in some sites it is given > row header as 40 bytes and in some 32 bytes > http://www.sbras.ru/rus/docs/db/postgres/doc/howto/faq-english.shtml#3.6 > http://www.softlab.ntua.gr/facilities/documentation/unix/postgres/faq-english.html > > Is the row header value is constant or it is variable?If so what could be the maximun value? > what is that additional +4bytes as pointer on page to tuple. > > Should all these were fixed or is there any command to find the values for these fields? Maybe you want: http://www.postgresql.org/docs/8.3/interactive/functions-admin.html pg_relation_size(text) Disk space used by the table or index with the specified name. The table name can be qualified with a schema name pg_total_relation_size(text) Total disk space used by the table with the specified name, including indexes and toasted data. The table name can be qualified with a schema name ? Cheers Tino