Re: WIP Incremental JSON Parser - Mailing list pgsql-hackers

From Jacob Champion
Subject Re: WIP Incremental JSON Parser
Date
Msg-id CAOYmi+=rFhT_muEeaUP6eJ-NETkfaPRbehrrdYD5+1S5fbfXqw@mail.gmail.com
Whole thread Raw
In response to Re: WIP Incremental JSON Parser  (Jacob Champion <jacob.champion@enterprisedb.com>)
List pgsql-hackers
On Mon, Mar 25, 2024 at 4:12 PM Jacob Champion
<jacob.champion@enterprisedb.com> wrote:
> Stack size should be pretty limited, at least on the platforms I'm
> familiar with. So yeah, the recursive descent will segfault pretty
> quickly, but it won't repalloc() an unbounded amount of heap space.
> The alternative would just be to go back to a hardcoded limit in the
> short term, I think.

And I should mention that there are other ways to consume a bunch of
memory, but I think they're bounded by the size of the JSON file.
Looks like the repalloc()s amplify the JSON size by a factor of ~20
(JS_MAX_PROD_LEN + sizeof(char*) + sizeof(bool)). That may or may not
be enough to be concerned about in the end, since I think it's still
linear, but I wanted to make sure it was known.

--Jacob



pgsql-hackers by date:

Previous
From: Tomas Vondra
Date:
Subject: Re: Statistics Import and Export
Next
From: Andrew Dunstan
Date:
Subject: Re: WIP Incremental JSON Parser