Re: Unbounded (Possibly) Database Size Increase - Toasting - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: Unbounded (Possibly) Database Size Increase - Toasting
Date
Msg-id 1021909168.14280.285.camel@taru.tm.ee
Whole thread Raw
In response to Re: Unbounded (Possibly) Database Size Increase - Toasting  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Unbounded (Possibly) Database Size Increase - Toasting  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Mon, 2002-05-20 at 16:08, Tom Lane wrote:
> Hannu Krosing <hannu@tm.ee> writes:
> > On Sun, 2002-05-19 at 19:37, Tom Lane wrote:
> >> I'd rather expect the toast indexes to grow given the lack-of-btree-
> >> collapse-logic issue. 
>
> > Why sould the toast indexes grow significantly more than the primary key
> > of main table ?
> 
> Well, the toast indexes will grow because they're using an OID key,
> and so the range of indexed values keeps increasing.  AFAIR Mark didn't
> say whether he *had* a primary key, let alone what it was --- but it's
> possible that he has one that has a range that's not changing over the
> test.

his table is this:

CREATE TABLE grow (id integer,body text,CONSTRAINT grow_pk PRIMARY KEY (id)) 
> In particular, if the test consists simply of updating the toasted
> field, that will not change the primary keys at all ... but it will
> change the toast table's key range, because each new value will get
> a new toast OID.

But does PG not have a new index entry for each _version_ of table row ?

Or does lack-of-btree-collapse-logic affect only keys where there are
many _different_ keys and not many repeating keys?

--------------
Hannu




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