Re: segfault with expression index, btree_gist and HOT Update

On 2018-Nov-07, Tobias Bussmann wrote:

> Hello,
> 
> my colleague Jürg Senn recently found a backend crash in Postgres 11 and trimmed it down to a reproducible test case.
Testingrevealed the crash is still present in last week's master branch but not in 10. I further simplified the test
caseto:
 
> 
> CREATE EXTENSION btree_gist;
> CREATE TABLE segfault (i int);
> CREATE INDEX ON segfault USING gist ((i + 10));
> INSERT INTO segfault VALUES (1);
> UPDATE segfault SET i = 2;
> 
> Our tests were performed on macOS: PostgreSQL 12devel on x86_64-apple-darwin17.7.0, compiled by Apple LLVM version
9.1.0(clang-902.0.39.2), 64-bit
 
> 
> Apparently the segfault happens within the check for the possibility of HOT Updates with expression / functional
indexeswhich was added by c203d6cf8 in 11.
 

Yeah, this code was disabled yesterday :-(  Updating to current tip of
either branch should "fix" it.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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