Pól: On Fri, May 28, 2021 at 11:36 AM Pól Ua Laoínecháin <lineh...@tcd.ie> wrote: > BIGINTEGER and INTEGER tables the same size? Comparing tables of 100M records. ... > test=# CREATE TABLE big_int (x BIGINT NOT NULL); > test=# CREATE TABLE int_32 (y INT); Bear in mind a row has more data than just the fields ( thingx like xmin,xmax and some others ) and there are alignment issues, and other things.
If, for example, the whole row needs to be 8-byte aligned on a synthetic example with a single field the rows may be the same lengths for both cases, note how your tables ocupy 3458Mb but the data is just 800/400 Mb. You may want to investgate putting some more realistic data ( i.e., try 2/4/8 fields per row ) to gain some insight, and reading https://www.postgresql.org/docs/current/storage-page-layout.html which gives some pointers on where to go next. Francisco Olarte.
