Re: Updating pg_attribute to change field's data type from integer to bigint on very large table

[Bèrto ëd Sèra <berto.d.sera@xxxxxxxxx>]

Hi Jeff,

read carefully, he said it does stuff ON DISK, which means that all of your fields must be physically remade (so it a lot more than telling it "it's an int4, Sheila", which is what just modifying the catalog would do). Since you are not a dba be aware that you are producing a new record for each of the existing ones, and thus bloating things quite a bit. You may want to vacuum it asap :)

Bèrto

On 13 April 2012 16:30, Jeff Adams <jeff.adams@xxxxxxxx> wrote:

so i can? if so, how do i go about? i should mention that, while i dabble in postgres dba activity, it is not my day job...

On Fri, Apr 13, 2012 at 11:27 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote:

I wrote:
> No, that is an actual on-disk change (making the field physically
> wider), so it's going to cost ya.  There are some cases where the
> on-disk representation doesn't change and so a catalog update isn't
> needed, but int4->int8 isn't one of them.

Sheesh, hit send too quickly on that.  Of course I meant "and so a
catalog update is all that's needed".

                       regards, tom lane

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Jeffrey D. Adams
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