Andrew Dunstan wrote:
>
>
> Simon Riggs wrote:
> >
> > - Heap-Only Tuples (HOT) accelerate space reuse for UPDATEs
> > change to
> > "Heap-Only Tuples (HOT) improve performance of frequent UPDATEs"
> >
> >
> >
>
> I think we need to qualify this, or it could be quite misleading.
> perhaps add "that don't affect indexed columns" or something like that.
This is covered in the detailed text below the item:
<para>
Heap-Only Tuples (<acronym>HOT</>) accelerate space reuse for
<command>UPDATE</>s (Pavan Deolasee, with ideas from many others)
</para>
<para>
<command>UPDATE</>s and <command>DELETE</>s leave dead tuples
behind, as do failed <command>INSERT</>s. Previously only
<command>VACUUM</> could reclaim space taken by dead tuples. With
<acronym>HOT</> dead tuple space can be reclaimed at the time of
<command>UPDATE</> or <command>INSERT</> if no changes are made to
indexed columns. This allows for more consistent performance.
Also, <acronym>HOT</> avoids adding duplicate index entries.
I just updated the wording so the index issue is clearer.
--
Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us
EnterpriseDB http://postgres.enterprisedb.com
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