Re: Tackling JsonPath support

On Mon, Dec 05, 2016 at 11:28:31AM -0500, Robert Haas wrote:
> The overall need is that it needs to be possible for PostgreSQL to
> throw an ERROR, and thus longjmp, without leaking resources.

As long as one can interpose jump buffers, that should be possible.

> Sometimes those errors happen asynchronously due to query cancel or
> replication conflicts or similar, and those don't have to be processed
> at once but the delay can't be unbounded or more than some modest
> fraction of a second. Integrating with PostgreSQL's memory-context
> stuff might make that or other resource leak problems easier, or it
> might not. To really get a clear notion of what would be involved, I
> think you'd probably need to produce a prototype patch and submit it
> here for review to really find out what issues people see with it.

Understood. Thanks.

> Library integrations are tricky but, since you wrote JQ and seem

Just to be clear, Stephen Dolan wrote jq. I've added to, and maintained
jq, to be sure, but I would not want to take credit from Stephen.

> potentially willing to modify it to work with PostgreSQL better, this
> one might be a lot less painful than some. I can't promise we'd
> accept an integration even if you came up with a patch, but I see
> looking back over this thread that there are several people cautiously
> supporting the idea of using JQ in some form, which is promising.

Fair enough. I won't be able to work on an integration for a few more
months, so we'll see (and Stephen might well veto some such changes to
jq), and it is time for me to shut up about this for now. Thanks for
the very useful comments, and sorry for the noise.

Nico
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