Re: [SPAM?]: Re: Support for REINDEX CONCURRENTLY

On 12/10/12 5:21 PM, Simon Riggs wrote:
> On 10 December 2012 22:18, Peter Eisentraut <peter_e@gmx.net> wrote:
>> On 12/8/12 9:40 AM, Tom Lane wrote:
>>> I'm tempted to propose that REINDEX CONCURRENTLY simply not try to
>>> preserve the index name exactly.  Something like adding or removing
>>> trailing underscores would probably serve to generate a nonconflicting
>>> name that's not too unsightly.
>>
>> If you think you can rename an index without an exclusive lock, then why
>> not rename it back to the original name when you're done?
> 
> Because the index isn't being renamed. An alternate equivalent index
> is being created instead.

Right, basically, you can do this right now using

CREATE INDEX CONCURRENTLY ${name}_tmp ...
DROP INDEX CONCURRENTLY ${name};
ALTER INDEX ${name}_tmp RENAME TO ${name};

The only tricks here are if ${name}_tmp is already taken, in which case
you might as well just error out (or try a few different names), and if
${name} is already in use by the time you get to the last line, in which
case you can log a warning or an error.

What am I missing?