Database structure question

[jennyflower]

Hi,

I am converting a visual fox pro database to Postgres. When converting this data are primary/foreign keys faster at looking up data then normal indexes?

Thanks

 

[ceco]

these are different things

foreign key is not an index at all (actually it only slows things down, a good idea is to put an index along with the foreign key)
primary key is implemented using index and should be as fast as UNIQUE index

both primary key and foreign key imply constraints the change the behaviour of queries
normal indexes are just indexes they are not constraints, they have only speed implications (may be for good, or for bad - updates, deletes get slower when more indexes exist on a table)

 

[jennyflower]

Ahh, ok, I think I get that.

Thanks