Re: Performance difference in accessing differrent columns in a Postgres Table

2018-07-29 Thread Pavel Stehule
2018-07-30 1:00 GMT+02:00 Tom Lane : > David Rowley writes: > > On 29 July 2018 at 17:38, Dinesh Kumar wrote: > >> I found performance variance between accessing int1 and int200 column > which > >> is quite large. > > > Have a look at slot_deform_tuple and heap_deform_tuple. You'll see > > that

Re: Performance difference in accessing differrent columns in a Postgres Table

2018-07-29 Thread Tom Lane
David Rowley writes: > On 29 July 2018 at 17:38, Dinesh Kumar wrote: >> I found performance variance between accessing int1 and int200 column which >> is quite large. > Have a look at slot_deform_tuple and heap_deform_tuple. You'll see > that tuples are deformed starting at the first attribute.

Re: Performance difference in accessing differrent columns in a Postgres Table

2018-07-29 Thread David Rowley
On 29 July 2018 at 17:38, Dinesh Kumar wrote: > I found performance variance between accessing int1 and int200 column which > is quite large. Have a look at slot_deform_tuple and heap_deform_tuple. You'll see that tuples are deformed starting at the first attribute. If you ask for attribute 200 t