Re: Re: BUG #10329: Could not read block 0 in file "base/56100265/57047884": read only 0 of 8192 bytes

Bruce Momjian <bruce@momjian.us> wrote:
> On Wed, Sep 10, 2014 at 02:07:36PM -0700, Kevin Grittner wrote:

>>  Bruce Momjian <bruce@momjian.us> wrote:
>>> On Sat, Sep  6, 2014 at 11:07:43AM -0400, Bruce Momjian wrote:
>>>> Here is a patch which implements the warning during CREATE INDEX
> ...
>>>> HASH.  If WAL-logging of hash indexes is ever implemented, we can remove
>>>> this warning.
>>>
>>> Applied, though I used the term "streaming standbys" to match our docs.
>>
>>  Hmm.  The wording of the warning doesn't seem to really indicate
>>  the full scope of the limitation.  Any a standby (warm or hot)
>>  maintained by WAL file copying would also be affected (i.e.,
>>  streaming replication as the WAL delivery mechanism is irrelevant),
>>  and you also have problems after a database crash or PANIC.  I'm
>>  not sure how to state that concisely, though.
>
> I am open to improved wording.  :-)

Instead of:

hash indexes are not WAL-logged so they are not crash-safe and cannot be used on streaming standbys

how about?:

hash indexes are not WAL-logged and thus are not crash-safe and cannot be used on standby servers

That seems consistent with the terminology used here:

http://www.postgresql.org/docs/current/interactive/warm-standby.html

--
Kevin Grittner
EDB: http://www.enterprisedb.com
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