| Lists: | pgsql-hackers |
|---|
| From: | Gregory Stark <stark(at)enterprisedb(dot)com> |
|---|---|
| To: | PostgreSQL-development Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Small Release Notes Comment |
| Date: | 2007-09-17 11:09:30 |
| Message-ID: | 87tzpto8et.fsf@oxford.xeocode.com |
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| Lists: | pgsql-hackers |
I think the change to the hash functions needs to be called out in the release
notes.
If anyone stored any results of hashintN, hashfloat8, etc in their database or
outside the database those results will have changed. It's fairly unlikely but
there could be someone out there doing that.
No intervention is required for normal expression indexes using those
functions or hash indexes which will be rebuilt during a database upgrade
anyways. I don't think hash_any itself changed so this wouldn't affect
hashtext or any hash function which was already using hash_any.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Gregory Stark <stark(at)enterprisedb(dot)com> |
| Cc: | PostgreSQL-development Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Small Release Notes Comment |
| Date: | 2007-11-01 22:38:11 |
| Message-ID: | 200711012238.lA1McBx10993@momjian.us |
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| Lists: | pgsql-hackers |
Gregory Stark wrote:
>
> I think the change to the hash functions needs to be called out in the release
> notes.
>
> If anyone stored any results of hashintN, hashfloat8, etc in their database or
> outside the database those results will have changed. It's fairly unlikely but
> there could be someone out there doing that.
>
> No intervention is required for normal expression indexes using those
> functions or hash indexes which will be rebuilt during a database upgrade
> anyways. I don't think hash_any itself changed so this wouldn't affect
> hashtext or any hash function which was already using hash_any.
Agreed. Added to the Migration section of the 8.3 release notes:
<listitem>
<para>
Internal hashing functions are now more uniformly-distributed (Tom)
</para>
<para>
If application code was calling and storing hash values using
internal <productname>PostgreSQL</> hashing functions, the hash
values must be regenerated.
</para>
</listitem>
I assume people will realize this does _not_ affect md5(), or should I
add a mention of that too.
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://postgres.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +