On 29 January 2018 at 13:34, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote:
> The important detail is that we only really care > about aborts in transactions that modified catalogs in some way (e.g. by > doing DDL). But we can safely decode (and stream) changes up to the > point when the catalogs get modified, so we can do two different things > at that point: Safely? Hmm. I think what we are missing here is a test case, or a detailed description of what we think happens. I can't see why a concurrent abort would be unsafe, as in, it would make decoding explode. If all it does is give the wrong answer when we process DDL, then all we have to do is check for abort before and after we process any DDL during decoding. Handling DDL is rare, so that test won't cost much in terms of handling DDL. So ISTM that we can continue decoding after we hit DDL, we just need some care. (My earlier comments were based on the idea that 2PC patch would simply block aborts, which of course will not work for streaming, hence the difference) -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
