Re: pgsql: Get rid of backtracking in jsonpath_scan.l

On 3/26/19 11:22 AM, Alvaro Herrera wrote:
> On 2019-Mar-26, Andrew Dunstan wrote:
>
>> On 3/25/19 8:44 AM, Alexander Korotkov wrote:
>>> Get rid of backtracking in jsonpath_scan.l
>>>
>>> Non-backtracking flex parsers work faster than backtracking ones. So, this
>>> commit gets rid of backtracking in jsonpath_scan.l. That required explicit
>>> handling of some cases as well as manual backtracking for some cases. More
>>> regression tests for numerics are added.
>> jacana appears to be having trouble with this:
>>
>>
>> 2019-03-26 00:49:02.208 EDT [5c99ae9e.20cc:6] LOG: server process (PID 8368) was terminated by exception 0xC0000028
> 0xC0000028 is STATUS_BAD_STACK, per
> https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/596a1078-e883-4972-9bbc-49e60bebca55
> Not sure how credible/useful a stack trace is going to be.
>

Right, and getting stack traces isn't easy in any case. There is a
gadget from Google that is supposed to trap exceptions and produce a
stack trace on the fly in mingw. I'm going to take a look at it,
although loading it might be ... interesting.

cheers

andrew

--
Andrew Dunstan https://www.2ndQuadrant.com
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